Redefining Mental Retardation in Capital Murder

Redefining Mental Retardation in Capital Murder

Of Unsound Mind

According to court records, Jorge Junior Vidal was born in Delano, California, on October 23, 1969 [See: People v. Superior Court (Vidal), 07 S.O.S. 1781; People v. Superior Court (Vidal), Ct. App. 5 F045226 (2004); People v. Vidal, Tulare County Super. Ct. No. 69782-C]. On January 24, 2001, Vidal was one of seven men who invited Eric Jones to enter a private garage to join them in “getting high.” Once inside the garage, instead of partying, Jones was bound, hands and feet, with an extension cord and beaten severely. Vidal reportedly stripped an electrical cord, attached the exposed ends to Jones’ fingers, poured water on the garage floor where Jones lay, repeatedly inserted and removed the plug from a wall outlet, and as Jones was being shocked, asked, “Are you feeling energized?” At some point, Jones’ clothes were cut off, and while he was being brutally sodomized, stabbed with a screwdriver, and jolted with a stun gun, music blasting from a car radio was used to drown out his screams. Eventually, Jones was thrown into the trunk of a car and driven to a field in southern Tulare County, where he was shot nine times at close range in the back and through his cheek. Left naked in the field, Eric Sean Jones, who was 17 years old at the time, bled to death within a few minutes, after having been tortured for nearly 2 hours. All this was apparently done in response to or in retribution for Jones’ earlier alleged attempt to steal Vidal’s car.

Three days after Jones was killed, Vidal and two others were arrested and charged with Jones’ “torture killing.” Of the seven men involved in the crime, two, Juan Dedios Soto and his younger brother Gerardo Soto, have yet to be apprehended and are believed to have fled to Mexico. Gerardo Zavala was convicted of second-degree murder and sentenced to 16 years to life. Keith John Seriales and Daniel Portugal were each convicted and sentenced to life in prison, without the possibility of parole. Tyrone Ebaniz’s conviction (for 1st degree murder, torture, and kidnapping) and sentence (36 years to life) has been overturned twice on appeal (because of error in jury instructions), with his third trial pending. Ebaniz was 16 years old at the time and, reportedly, Jones’ best friend.

Vidal was charged with murder (with special circumstances and enhancement), torture, forcible sexual penetration, sexual assault in concert, unlawful sexual penetration of person under age 18, kidnapping, false imprisonment, multiple counts of unlawful weapon possession, and other lesser charges. The prosecution filed the case as a capital offense; the defense responded by filing a motion to preclude the imposition of the death penalty under Atkins, as implemented in California law [See: Atkins v. Virginia, 536 U.S. 304 (2002) and California Penal Code Section 1376]. California law allows defendants a choice in this matter: to have the issue decided by a judge in a pretrial hearing or by a jury after the guilt phase of trial. Opting for the former, in October 2003 and March 2004, Vidal’s motion was heard during an evidentiary hearing.

Proving Mental Retardation

As might be expected, psychological experts for the defense (who has the burden of proof) and the prosecution disagreed as to whether Vidal met the legal standard for mental retardation. Consistent with the clinical diagnosis of mental retardation or intellectual disability of both the American Association on Intellectual and Developmental Disabilities [AAIDD; known as the American Association on Mental Retardation (AAMR) prior to 01/01/07] and the American Psychiatric Association (APA), the legal definition of mental retardation set forth in both Atkins and the California Penal Code involves a three-pronged test: significantly sub-average general intellectual functioning, which must exist concurrently with deficits in adaptive behavior, and which must have a manifest onset before the age of 18 (AAMR, 2002; West, 2007; APA, 2000; Atkins v. Virginia, 2002).

In assessing the first prong of mental retardation—Vidal’s general intellectual functioning—the psychologists were able to review several standardized intelligence tests administered to Vidal through the public school system as early as 1980 (when he was 11), as well as one administered by a defense expert in 2003. Across administrations, Vidal consistently scored in the mentally retarded range in terms of his Verbal Intelligence Quotient (VIQ), while his Performance Intelligence Quotient (PIQ) ranged from average to high average (See Table 1). Vidal’s Full Scale Intelligence Quotient (FSIQ) ranged from borderline mental retardation to average intelligence. With each administration, there was a strikingly significant split between his VIQ and PIQ.

In addition to administering the Wechsler Abbreviated Scale of Intelligence to Vidal in 2003, the defense expert, psychologist Eugene Couture, also administered the Peabody Picture Vocabulary Test, which is designed to assess the respondent’s ability to understand spoken language. As Vidal’s first language was Spanish, the Peabody was given in both English and Spanish, with Vidal scoring in the lowest percentile on both versions (as he had on prior administrations in 1980 and 1989).

According to family members, it was clear early on that Vidal was “not very smart.” His older sister noted his ability to read and write was not the same as his peers and that, even with help, he was unable to understand and complete homework assignments. As early as kindergarten, Vidal’s academic records identified him as having language problems. He was held back in the 4th grade, and while his communication skills had improved somewhat by the 9th grade, Vidal was never completely fluent in Spanish or English (he was never able to read or write anything beyond the simplest of words) and had difficulty understanding both languages. Throughout his school years, Vidal took approximately seven achievement tests, never performing at grade level (with the exception of scoring at the 12th-grade level on a letter identification subtest when in 8th grade) and never showing improvement between administrations. Several individualized educational plans were constructed (and unsuccessfully implemented) for Vidal and he received the support of special education services or a resource specialist throughout his education. While he reached the 12th grade, Vidal did not graduate and never functioned beyond a 2nd- or 3rd-grade level academically.

To address the second prong of mental retardation, “deficits in adaptive functioning,” Couture administered the Vineland Adaptive Behavior Scales, using Vidal’s sisters and ex-wife as informants. Vidal’s scores were below 70 on “daily living,” “communication,” and “social” across informants, while Vidal rated himself as below 70 on only two of the three subscales. In addition to standardized test results, lay witnesses described Vidal’s historical difficulties with routine tasks and with remembering chores and household rules. Thirty-two years old at the time of Jones’ murder, Vidal never lived independently, only leaving his mother’s home when he married. The father of several children, Vidal was described as a loving father who occasionally provided his children with a degree of care. Over the years, Vidal had worked as a seasonal field laborer.

After hearing all the evidence, in mid-March 2004, the Superior Court judge ruled that Vidal had met his burden of proof. The judge reasoned that Vidal’s VIQ (combined with clear deficits in adaptive functioning) was sufficient to establish a severe lack of verbal ability that went to the issues of “premeditation, deliberation, appreciation of concepts of wrongful conduct, ability to think and weigh reasons for and not for doing things and logic [and] foresight,” as proscribed by Atkins. A finding that Vidal was, in fact, mentally retarded was issued, thereby blocking the prosecution from seeking the death penalty.

The prosecution appealed the decision in the 5th District Court of Appeals on several grounds. Most relevant to this discussion was the People’s contention that the trial court “exceeded its jurisdiction” by basing its decision on the defendant’s VIQ score—rather then the FSIQ score—combined with adaptive behavior scores. The People argued that Vidal’s behavior in the instant offense calls into question the nature and degree of any manifest adaptive deficits and that while his VIQ had been consistently low, his PIQ and FSIQ argued against mental retardation. In May 2005, the lower court’s ruling was reversed when, in a split decision, the Appeals Court held that the FSIQ is (or should be) the primary determinant of intellectual functioning and mental retardation.

Intellectual Error

Since 1976, when the death penalty was reinstated, approximately 44 persons with mental retardation have been executed, with others pending (Keyes, Edwards, & Perske, 2002). In Virginia, a mentally retarded man sat on death row for 10 years before being exonerated by DNA evidence (Elgie, 2001). In Texas, a man is awaiting execution whose IQ scores (on three different administrations), as entered into evidence, were 65, 68, and 74 (Clark v. Dretke, 2004). Before the U.S. Supreme Court decided Atkins in 2002, 18 states and the federal government had existing laws that banned the execution of persons identified as mentally retarded. Of those 19 jurisdictions, nine specified a FSIQ score of 70 or below (on a standardized assessment procedure) as the cut-off for classification.

However, when the Supreme Court published its opinion in Atkins, it did not operationally define, delimit, or quantify “subaverage general intellectual functioning” or “deficits in adaptive functioning.” The Court intentionally did not provide a specific cut-off score for mental retardation or identify a particular measure (or measures) to be employed in that determination. The Court’s intention was that the best measure of intellectual functioning remains a matter of fact to be resolved on the trial court level, based on the evidence unique to each given case.

Despite this, of the eight states that passed new legislation to be in compliance with Atkins, two opted to institute a cut-off FSIQ of 70 and one, a FSIQ of 75. Like Atkins, the remaining states’ statutes had no fixed IQ score, thereby allowing trial courts greater flexibility in determining the degree of weight given to different categories of evidence. In those states, which include California, the trier of fact is bound to treat each defendant individually when determining whether the death penalty is an appropriate sentencing option.

Given this, on April 2007, the California Supreme Court unanimously overturned the Fifth District Court of Appeals ruling in Vidal. In writing the opinion, Justice Werdegar noted that the District Court erred in presuming that the best measure of intellectual functioning is a matter of law when in actuality, it is a factual question to be determined or decided in each case by the trier of fact. In turn, the Supreme Court concluded that the trial court judge did not exceed his authority or use an incorrect standard when finding Vidal was mentally retarded. In other words, although Vidal’s FSIQ scores were generally within the standard average range of intellectual functioning, as a matter of law that fact alone does not preclude a finding of mental retardation. Because Atkins does not incorporate the set requirement of a specific test score, the Supreme Court did not find error in the trial court giving greater weight to one piece of evidence (Vidal’s VIQ) over another (his FSIQ), even when the evidence comes from the same source or test.

Between Black and White

There are issues in the domain of forensic psychology where clinical definitions are not a clean match to legal definitions, nor do they directly inform the factual question at hand. The definition and determination of mental retardation appears to be one such issue. In terms of clinical diagnosis, the purported purpose of which is to direct treatment interventions, the APA has established three criteria for a diagnosis of mental retardation: “significantly subaverage intellectual functioning”; concurrent “deficits or impairments in adaptive functioning”; and onset of these indicators before age 18 (APA, 2000).

To be diagnosed with “mild mental retardation,” the APA requires an approximate IQ score of 70 or below (on an individually administered test). The more impaired subcategories of mental retardation (i.e., moderate, profound, and severe) do not have a set range of scores, but allows for a “give-or-take” of 5 to 10 points. The APA’s adaptive functioning criterion is defined as “the person’s effectiveness in meeting the standards expected for his or her age by his or her cultural group.” To meet this criteria, the individual must demonstrate deficits or impairments in at least two areas specified by the APA. These include communication, social/interpersonal skills, self-care, health, safety, home living, use of community resources, self-direction, functional academic skills, work, and leisure.

The Social Security Administration (SSA) uses comparatively flexible eligibility requirements (in terms of qualifying criteria, domains, cut-off scores, and age) when classifying individuals as mentally retarded for the purpose of assigning financial benefits (SSA, 2003). The AAIDD, which influences the definition of mental retardation used by other agencies and service providers (such as the Department of Education), is expected to issue a new definition of mental retardation or intellectual disability in 2009 or 2010. As with the APA, the AAIDD’s existing definition requires “subaverage intellectual functioning,” “deficits or impairments in adaptive functioning,” and onset/manifestation by the age of 18 years (this is to rule out brain/neurological damage in a previously non-retarded adult) (AAMR, 2002). In order to account for measurement error, the AAIDD’s ceiling for “subaverage intellectual functioning” is an IQ score of 75, or a score representing at least two standard deviations above the mean on a standardized test.

The AAIDD currently defines adaptive behavior as “the collection of conceptual, social, and practical skills that people have learned so they can function in their everyday lives.” According to the AAIDD, significant limitations in adaptive functioning “impact a persons’ daily life and affect the [individual’s] ability to respond to a particular situation or to the environment.” When standardized tests are used to assess “deficits or impairments in adaptive functioning,” the AAIDD requires a score of at least two standard deviations below the mean on a measure of one or more of the three domains. While adaptive functioning can be assessed by standardized measures, it is often determined by subjective impressions, reported observations, integrated documentation, and/or clinical assessment.

How mental retardation is defined has bearing on several legal issues, such as determining juvenile fitness and adult competence, proving certain elements of murder, and whether the death penalty is an appropriate sentence in a given case. In the context of capital murder by defendants who are mentally retarded, the Atkins Court found that, “Because of their disabilities in areas of reasoning, judgment, and control of their impulses, however, they do not act with the level of moral culpability that characterizes the most serious adult criminal conduct. Moreover, their impairments can jeopardize the reliability and fairness of capital proceedings against mentally retarded defendants.”

Redefining Mental Retardation

In 2005, the California Supreme Court chose not to adopt an IQ score of 70 as the upper limit for making a “prima facie” showing of mental retardation (Hawthorne, 2005). Rather than base the finding on a single test score (measuring either intellectual or adaptive functioning), the Court concluded that making a finding of mental retardation requires “an assessment of the individual’s overall capacity, based on a consideration of all the relevant evidence.” In 2007, with Vidal, the Court went further, holding that even with a FSIQ score that would preclude clinical diagnosis, a defendant may be found mentally retarded based on subscores of the same test (provided the other two prongs of mental retardation have been proved).

Many states (and expert witnesses) have held to a definitive IQ score cut-off despite the clear intention of Atkins. Using a cut-off score obviously makes the decision of whether a defendant is mentally retarded a simple one; it is not, however, sufficient to make the decision one that is definitively accurate or just. Our understanding of intelligence is constantly evolving, with no universally accepted definition of the construct itself. Likewise, our understanding of how to best measure “intelligence” is evolving. While re-norming standardized intelligence tests may help offset the Flynn Effect, defendants tested at either end are at risk of being misdiagnosed, especially if experts do not determine exactly when each test was administered in the given test’s life-cycle.

To ensure that neither proceedings nor the punishment of a capital crime of those with mental retardation is cruel, unusual, or excessive, the trier of fact must be given more information than is necessary for making a clinical diagnosis. As was the case for Vidal, a defendant may have a FSIQ that precludes a diagnosis of mental retardation, but may manifest significant deficits in components of intelligence that have great legal relevance, such as in the ability to process information. Another defendant may have IQ scores that indicate retardation, yet possess the capacity to create intent and to kill with premeditation by “lying in wait.” As noted in Atkins, “there are many persons who have been diagnosed as mentally retarded who know the difference between right and wrong and are competent to stand trial, but, by definition, they have diminished capacities to understand and process information, to communicate, to abstract from mistakes and learn from experience, to engage in logical reasoning, to control impulses, and to understand others’ reactions. Their deficiencies do not warrant an exemption from criminal sanctions, but diminish their personal culpability.”

A thorough forensic evaluation of intellectual and adaptive functioning must address each and every aspect of intelligence as provided in the legal definition of mental retardation. For example, beyond the initial question of whether the defendant knows right from wrong in both a social and cultural context, comes the matter of how complex a moral question the defendant can answer. Beyond that, how capable is the defendant of controlling his or her impulses, and in the context of what degree and nature of internal and external pressures? Ultimately, the expert witness must provide information for the trier of fact to use in deciding whether the defendant meets the legal definition of mental retardation, a definition that determines moral culpability.

References

American Association on Mental Retardation (AAMR). (2002). Mental retardation: Definition, classification, and systems of supports (10th ed.) Annapolis, MD: Author.

American Psychiatric Association (APA). (2000). Diagnostic and statistical manual of mental disorders, 4th edition – test revision (DSM IV-TR). Arlington, VA: Author.

Atkins v. Virginia, 536 U.S. 304 (2002).

Clark v. Dretke, No. 5:04-cv-00124-DF (2004).

Elgie T. (2001, July 10). The death penalty in Virginia: Attempts at legislative reform. The Richmond Journal of Law and the Public Interest. Retrieved June 18, 2007, from http://law.richmond.edu/rjolpi/Issues_Archived/2001_Spring_Issue/Elgie.html

Keyes, D., Edwards, W., & Perske, R. (2002). People with mental retardation are dying—legally: At least 44 have been executed. Mental Retardation, 3, 243–244.

Penry I (Penry v. Lynaugh, 492 U.S. 302 (1989).

Penry II (Penry v. Johnson, 532 U.S. 782 (2001) (Penry II).

People v. Hawthorne, 35 Cal.4th 40 (2005).

People v. Superior Court (Vidal), 07 S.O.S. 1781.

People v. Superior Court (Vidal), Ct.App. 5 F045226 (2004).

People v. Vidal, Tulare County Super. Ct. No. 69782-C.

Social Security Administration (SSA), Office of Disability Programs. (2003). Disability evaluation under social security. [SSA Pub. No. 64-039]. Washington, DC: U.S. Government Printing Office.

West. (2007). California penal code section 1376. Retreived June 18, 2007, from http://www.leginfo.ca.gov/cgi-bin/displaycode?section=pen&group=01001-02000&file=1367-1376

About the Author

Bruce Gross, PhD, JD, MBA, is a Fellow of the American College of Forensic Examiners and is an Executive Advisory Board member of the American Board of Forensic Examiners. Dr. Gross is also a Diplomate of the American Board of Forensic Examiners and the American Board Psychological Specialties. He has been an ACFEI member since 1996 and is also a Diplomate of the American Psychotherapy Association.

In two separate but related decisions, in 1989 and 2001, the United States Supreme Court held that mental retardation is a mitigating factor to be considered by capital juries during sentencing, that the class of individuals diagnosed as “mentally retarded” is not homogeneous in terms of their capacity for legal and moral culpability, and that capital punishment of mentally retarded persons is not a universal or per se violation of the Eighth Amendment’s protection against “cruel and unusual punishment” (Penry I, 1989; Penry II, 2001). One year later, in deciding the 2002 case of Atkins v. Virginia, the Court noted the shift in social thought and practice regarding the execution of mentally retarded defendants, reversed its position in Penry, and made the mentally retarded a class exempt from the death penalty. In April 2007, a ruling by the California Supreme Court gave trial court judges broader discretion in determining if a defendant is mentally retarded and, therefore, exempt from the death penalty. Not only in California, but throughout the United States, this ruling has the potential to affect those persons on death row and currently facing capital charges whose intellectual functioning borders on the classification of mentally retarded.

Fall 2007 THE FORENSIC EXAMINER

By Bruce Gross, PhD, JD, MBA, FACFEI, DABFE, DABPS, DABFM, DAPA

The American College of Forensic Examiners

Antidepressant Withdrawal Syndrome and DUI Evaluation

Antidepressant Withdrawal Syndrome and DUI Evaluation

By Henry Spiller, MS, DABAT, FACFEI, DABFE, and Tama S. Sawyer, PharmD, CSPI

Key Words: withdrawal syndrome, DUI, selective serotonin reuptake inhibitor

Abstract

Millions of Americans annually receive selective serotonin reuptake inhibitor antidepressants and dual-action antidepressants for their symptoms of depression. These patients are at risk for a well-documented withdrawal syndrome if they abruptly stop their medication. This withdrawal syndrome may produce significant effects that may impair a person’s ability to drive, putting at risk both the driver and others on the road. In a situation of the antidepressant withdrawal syndrome, the impairment is due to the absence of drugs in the patient, producing the paradox of a potentially impaired driver because of an absence of the influence of a drug. This article reviews the antidepressant withdrawal syndrome and describes the effects on cognition, memory, vision, and motor performance and reviews how these clinical effects might be misinterpreted using standardized field sobriety tests suggesting the patient is intoxicated in the absence of other drugs or alcohol.

THE FORENSIC EXAMINER Fall 2007

This article is approved by the following for continuing education credit:

(ACFEI) The American College of Forensic Examiners International provides this continuing education credit for Diplomates.

(CFC) The American College of Forensic Examiners International provides this continuing education credit for Certified Forensic Consultants.

The American College of Forensic Examiners International is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. This activity has been planned and implemented in accordance with the Essential Areas and Policies of the Accreditation Council for Continuing Medical Education (ACCME). The American College of Forensic Examiners International designates this educational activity for a maximum of 1 hour AMA PRA Category 1 Credits™.. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Introduction

Worldwide use of antidepressants has increased dramatically in the past decade (Berndt, Bhattacharjya, Mishol, Arcelus, & Lasky, 2002; Ciuna et al., 2004; Helgason, Tomasson, & Zoega, 2004; Hemels, Koren, & Einarson, 2002). Use of antidepressants may range from 26 to 72 defined daily doses per 1000 people, depending on the country (Ciuna et al.; Helgason et al.; Hemels et al.). The estimated range of Americans using antidepressants is from 7 to 18 million patients annually. Of the various classes of antidepressants available, the Selective Serotonin Reuptake Inhibitors (SSRI) and Dual Action Antidepressants (DAA), involving serotonin and norepinephrine reuptake inhibition, make up more than 75% of the prescriptions filled for antidepressants (Berndt et al.; Hemels et al.). Additionally, use of SSRIs and DAAs has increased more than 600% in the last 10 years (Ciuna et al.). While the drugs in these two classes have proven to be generally safe and effective, studies have documented a problem with the effects of withdrawal (Stahl et al., 1997).

Though symptoms from withdrawal are diverse, all include effects on cognition (impaired concentration and/or confusion) and motor performance (impaired coordination, loss of balance). (See Table 2 for a complete list of the clinical effects reported with withdrawal syndrome associated with the SSRI and DAA drugs.) These withdrawal effects may put patients at risk of impaired driving in the absence of other drugs or alcohol. While this is a potentially serious problem for both the patient/driver and others on the road, it has not been previously explored in the literature. This article describes the withdrawal syndrome associated with the SSRI and DAA drugs including clinical effects, with a focus on the potential effects these drugs may have on driving. Additionally, this article includes a discussion on the impact antidepressant withdrawal syndrome might have on field evaluation of a driver with tests such as the standard field sobriety test.
Antidepressant Withdrawal syndrome

Several groups of antidepressants, including the tricyclic antidepressants, the tetracyclic antidepressants, the SSRIs, the DAAs, and newer antidepressants such as mirtazapine (Remeron), may produce a withdrawal syndrome (Benazzi, 1998a; Coupland, Bell, & Potokar, 1996; Dilsaver, Kronfol, Sackellares, & Greden, 1983; Hindmarch, Kimber, & Cockle, 2000; Rosenbaum, Fava, Hoog, Ascroft, & Krebs, 1998). However, the withdrawal syndrome produced by the SSRIs and the DAAs is clinically different from that produced by the classic tricyclic antidepressants (Lejoyeux, Ades, Mourad, Solomon, & Dilsaver, 1996; Stahl et al., 1997). The withdrawal syndrome from the tricyclic and tetracyclic antidepressants is primarily a cholinergic syndrome with symptoms such as nausea, vomiting, anorexia, diarrhea, rhinorrhea (runny nose), diaphoresis (excessive sweating), myalgias (muscle pain), increased anxiety, agitation, and sleep disturbances (Dilsaver, 1994; Dilsaver et al.). In contrast, the withdrawal syndrome from the SSRIs and DAAs is primarily a serotonergic syndrome, with symptoms such as dizziness, lethargy, impaired concentration, electric-like shock sensations, impaired coordination, blurred vision, and sleep disturbances (see Table 2). This article discusses the impact of the serotonin-related antidepressants. The SSRI and DAA drugs that may produce a withdrawal syndrome are listed in Table 1. The syndrome may be seen in a substantial minority of patients taking these drugs—up to 25% (Coupland et al.; Michelson et al., 2000; Rosenbaum et al., 1998).

A brief understanding of the mechanism(s) of action of these drugs will improve the understanding of the withdrawal syndrome. The selective serotonin reuptake inhibitor class includes 6 drugs that are widely available. (See Table 1 for a list of drugs in this class with associated pharmacokinetic information.) These drugs inhibit the human serotonin transporter, inhibiting re-uptake of serotonin into presynaptic neurons (Schmidt, Fuller, & Wond, 1988). This allows for persistence of serotonin in the neuronal synapse and increased serotonergic neuron transmission. In effect, it increases activity on the pathways of the brain that use serotonin as the neurotransmitter. Chronic use has been shown to cause reduced serotonin transporter density, maintenance of normal cell-firing rates, and increased activation of post-synaptic firing.

The SSRIs produce little or no clinically significant activity on dopamine, norepinephrine, histamine, or acetylcholine receptors, or re-uptake transporters. The DAAs inhibit both the human serotonin transporter and the human norepinephrine transporter, inhibiting re-uptake of both serotonin and norepinephrine. The end result of the actions of both these classes of drugs is increased nerve transmission in select areas of the brain because of prolonged duration of neurotransmitters in the synapse. The sudden withdrawal of these drugs produces a sudden decrease in serotonin transmission due to reduced persistence of the neurotransmitter in the synaptic cleft (Zajecka, Tracey, & Mitchell, 1997). In effect, it produces a reduction of activity in some areas of the brain controlled by serotonin in the case of SSRIs and by serotonin and norepinephrine in the case of the DAAs.

It is this sudden decrease in activity that is responsible for the effects seen in these patients. If the decrease is of sufficient magnitude, an antidepressant withdrawal syndrome will occur. The dosage range of these drugs varies, with as much as a five-fold difference in some of the drugs between the lower and upper range of the therapeutic dose. (See table 1.) Any decrease that significantly effects serotonin transmission may produce a withdrawal syndrome. The withdrawal syndrome is transitory but may persist for days to weeks as the brain adjusts to new levels of activity on these neuronal pathways. Additionally, the syndrome may be reversed by restarting the antidepressant therapy. The true incidence of the withdrawal syndrome is unclear, with reports suggesting that 3%–30% of patients experience some form of the syndrome (Coupland et al., 1996; Oehrberg et al., 1995; Stahl et al., 1997).

The most frequently reported symptoms from the serotonin antidepressant withdrawal syndrome are dizziness, altered balance, lethargy, parathesias (numbness, tingling feeling, electric shock-like sensations), nausea, behavioral changes, and sleep disturbances. The clinical effects that can occur with the antidepressant withdrawal syndrome are diverse, and a broader list is provided in Table 2. It should be noted that the syndrome is varied from patient to patient—from mild to severe—and not all symptoms will be seen in every patient.

Criteria for diagnosis of antidepressant withdrawal syndrome vary, but generally include sudden discontinuance or reduction of dosage of an SSRI or DAA after a period of at least 1 month of use, two or more symptoms from Table 2, and symptoms not triggered by a general medical condition or other recognized cause (Black, Shea, Dursun, & Kutcher, 2000; Ditto, 2003). The onset of symptoms may be interpreted as a return of psychiatric symptoms (Benazzi, 1998b). Additionally, it may be interpreted by the patient as the onset of a flu-like syndrome (nausea, fatigue/lethargy, dizziness) along with return of depression (behavioral changes and sleep disturbances). The symptoms may be sufficiently severe to interrupt activities of daily living, such as going to work or driving a car, and patients should be warned about the dangers of operating a motor vehicle if they begin experiencing moderate to severe withdrawal symptoms. In some cases, the symptoms may be severe enough for the patients to recognize they should not drive (Campagne, 2005). However, in other cases, the patients may not recognize the degree of impairment and attempt to continue with their daily lives including commitments to work, school, or other outside commitments.

Patients may have an interruption in their medication for a number of reasons. They might miss one or several days of therapy due to non-compliance (“drug holiday”) (Hylan, Dunn, Tepner, & Meurgey, 1998) or there may be an interruption in the patients’ medication supply due to travel, lack of access to a pharmacy, or inability to pay (Campagne, 2005). In some cases, the patient will suddenly stop taking the medication due to perceived problems with the side effects of the medication itself (Leiter, Nierenberg, Sanders, & Stern, 1995).

Symptoms of the SSRI and DDA withdrawal syndrome may occur from as early as 12 hours after a missed dose and up to 3 weeks after discontinuance, although the average time of onset of symptoms is 1 to 3 days (Campagne, 2005; Zajecka et al., 1997). One factor impacting the onset of symptoms is the half-life of the drug involved, which can vary significantly depending on the drug involved (Michelson et al., 2000) (See Table 1).

Withdrawal Syndrome and Driving

Generally speaking, impaired driving (driving while intoxicated) is considered secondary to the effects of drugs or alcohol while these substances are in the patient and producing a direct effect on cognition, attention, motor control, and reaction time. However, in the situation of the antidepressant withdrawal syndrome, the impairment is due to the absence of drugs in the patient. This produces the paradox of a potentially impaired driver that is not under the influence of any drugs or alcohol. While there may be significant impairment, the term driving under the influence may be an inappropriate term for these cases.

There are a number of symptoms of the withdrawal syndrome that could potentially cause a patient to operate a motor vehicle in a manner that might be interpreted as operating under the influence of alcohol or drugs. These symptoms include visual disturbances, dizziness/vertigo, impaired coordination, tremors, confusion, impaired concentration, and jerking eye movements that cause difficulty with tracking and memory impairment. These clinical effects might produce an altered driving pattern, including weaving, erratic speed and erratic lane changes, which might be interpreted as driving while intoxicated. Additionally, if the vehicle were stopped for possible impaired driving and the patient evaluated, there are a number of symptoms that might be interpreted as the patient being under the influence of drugs or alcohol. These symptoms include confusion, agitated behavior, distracted affect if the patient is experiencing repeated sensations of electric shocks, an unsteady gait, and inattention to questions because of inability to hear on account of tinnitus.

Withdrawal Syndrome and the Standard Field Sobriety Test

When a police officer stops a driver for suspicion of impaired driving, the most common procedure is to have the driver perform a field sobriety test. The National Highway Traffic and Safety Administration (NHTSA) has validated three tests that have become generally recognized as the Standardized Field Sobriety Test (Tharp, Burns, & Moskowitz, 1981). These three tests are the Walk and Turn (WAT), Horizontal Gaze Nystagmus (HGN), and One Leg Stand (OLS). However, other tests may be performed at the discretion of the police officer or local jurisdiction such as asking the driver to count backwards from a certain number and to stop at a certain number (e.g. count down from 55 to 18) or to recite the alphabet beginning at a particular letter and ending at a particular letter (e.g., beginning at F and ending at R). These latter tests have not been validated by NHTSA.

In the course of administering the WAT, the subject is given oral instructions to take nine steps heel-to-toe along a straight line. After taking nine steps the subject must execute a one-foot turn and return in the same manner in the opposite direction. There are 7 indicators of impairment for which the police officer is instructed to watch to indicate successful completion or failure of the test: 1) subject cannot maintain balance while listening to instructions, 2) subject begins test before instructions are complete, 3) subject stops to regain balance while walking, 4) subject does not touch heel-to-toe, 5) subject uses arms to maintain balance, 6) subject loses balance during turn, and 7) subject takes incorrect number of steps. In a patient experiencing antidepressant withdrawal syndrome, there are a number of symptoms that would cause them to fail the WAT test, even in the absence of intoxicants. The most important of these are gait instability, dizziness/vertigo, lack of coordination, and loss of balance. Additionally, such symptoms as confusion, impaired concentration, and short-term memory impairment might cause the patient to fail by beginning too soon, failing to take the correct number of steps, or failing to walk heel-to-toe on the return walk.

In the course of administering the HGN, the subject is instructed to focus on an object 12 to 15 inches in front of his or her face as the object is moved horizontally to the left and right. The police officer is instructed to watch for smooth pursuit, nystagmus before onset of 45 degrees, distinct nystagmus at maximal deviation, and head movements and/or jerks. A patient experiencing antidepressant withdrawal syndrome might fail the HGN because of misinterpretation of already existing jerking eye movements and blurred vision.

In the course of administering the OLS, the subject is instructed to stand with one foot held approximately 6 inches off the ground and to count by thousands (e.g. one thousand one, one thousand two, etc.) until told to put the foot down. The subject is timed for 30 seconds. There are 4 indicators of impairment that the police officer is instructed to watch for to indicate successful completion or failure of the test: 1) swaying while balancing; 2) using arms to balance; 3) hopping to maintain balance; and 4) putting the raised foot down. There are numerous symptoms that could cause a patient experiencing antidepressant withdrawal syndrome to fail the OLS test, even in the absence of intoxicants. The most important of these are dizziness/vertigo, lack of coordination, and loss of balance.

Finally, the patient may be agitated and experiencing significant anxiety. The patient’s behavior may initially be interpreted by the police officer as a refusal to obey commands during the initial evaluation or during one of the SFSTs. In either case, refusal may be interpreted as reason to suspect intoxication.

It should be noted that the primary role of field sobriety tests is to give the police officer a reasonably accurate tool to determine if intoxication might be suspected and if further verifiable documentation such as an alcohol breathalyzer test or blood alcohol test should be administered. The tests themselves should not be sufficient evidence of intoxication without clinical evidence such as a breathalyzer test or blood alcohol test. In the case of drug intoxication, field sobriety tests again are not sufficient evidence of intoxication without supporting evidence of a blood concentration of the suspected drug. Because of situations such as the antidepressant withdrawal syndrome, the field sobriety tests may provide misleading indications of intoxication when no intoxication has occurred.

Conclusion

Millions of Americans annually receive SSRIs and DAAs for their symptoms of depression. These patients are at risk for a well-documented withdrawal syndrome if they abruptly stop their medication. The antidepressant withdrawal syndrome may produce significant effects on cognition and motor performance. Further, these effects might be misinterpreted in the use of standardized field sobriety tests to suggest the patient is intoxicated in the absence of other drugs or alcohol.

References

Benazzi, F. (1998a). Mirtazapine withdrawal symptoms. Canadian Journal of Psychiatry, 43(5), 525.

Benazzi, F. (1998b). Sertraline discontinuation syndrome presenting with severe depression and compulsions. Biological Psychiatry, 43(12), 929–930.

Berndt, E. R., Bhattacharjya, A., Mishol, D. N., Arcelus, A., & Lasky, T. (2002). An analysis of the diffusion of new antidepressants: Variety, quality, and marketing efforts. Journal of Mental Health Policy and Economics, 5(1), 3–19.

Black, K., Shea, C., Dursun, S., & Kutcher, S. (2000). Selective serotonin reuptake inhibitor discontinuation syndrome: proposed diagnostic criteria. Journal of Psychiatry and Neuroscience, 25(3), 255–261.

Campagne, D. M. (2005). Venlafaxine and serious withdrawal symptoms: Warning to drivers. Medscape General Medicine, 7(3), 22.

Ciuna, A., Andretta, M., Corbari, L., Levi, D., Mirandola, M., Sorio, A., et al. (2004). Are we going to increase the use of antidepressants up to that of benzodiazepines? European Journal of Clinical Pharmacology, 60(9), 629–634.

Coupland, N. J., Bell, C. J., & Potokar, J. P. (1996). Serotonin reuptake inhibitor withdrawal. Journal of Clinical Psychopharmacology, 16(5), 356–62.

Dilsaver, S. C. (1994). Withdrawal phenomena associated with antidepressant and antipsychotic agents. Drug Safety, 10(2), 103–114.

Dilsaver, S. C., Kronfol, Z., Sackellares, J. C., & Greden, J. F. (1983). Antidepressant withdrawal syndromes: Evidence supporting the cholinergic overdrive hypothesis. Journal of Clinical Psychopharmacology, 3(3), 157–164.

Ditto, K .E. (2003). SSRI discontinuance syndrome: Awareness as an approach to prevention. Postgrad Medicine, 114(2), 79–84.

Helgason, T., Tomasson, H., & Zoega, T. (2004). Antidepressants and public health in Iceland. Time series analysis of national data. British Journal of Psychiatry, 184(2), 157–162.

Hemels, M. E., Koren, G., & Einarson, T. R. (2002). Increased use of antidepressants in Canada 1991–2000. Annals of Pharmacotherapy, 36(9), 1375–1379.

Hindmarch, I., Kimber, S., & Cockle, S. M. (2000). Abrupt and brief discontinuation of antidepressant treatment: Effects on cognitive function and psychomotor performance. International Clinical Psychopharmacology, 15(6), 305–318.

Hylan, T. R., Dunn, R. L., Tepner, R. G., & Meurgey, F. (1998). Gaps in antidepressant prescribing in primary care in the United Kingdom. International Clinical Psychopharmacology, 13(6), 235–243.

Leiter, F. L., Nierenberg, A. A., Sanders, K. M., & Stern, T. A. (1995). Discontinuation reactions following sertraline. Biological Psychiatry, 38(10), 694–695.

Lejoyeux, M., Ades, J., Mourad, I., Solomon, J., & Dilsaver, S. (1996). Antidepressant withdrawal syndrome. Recognition, prevention and management. CNS Drugs, 5(4), 278–292.

Michelson, D., Fava, M., Amsterdam, J., Apter, J., Londborg, P., Tamura, R., et al. (2000). Interruption of selective serotonin reuptake inhibitor treatment: Double-blind placebo-controlled trial. British Journal of Psychiatry, 176(4), 363–368.

Oehrberg, S., Christiansen, P. E., Behnke, K., Borup, A. L., Severin, B., Soegaard, J., et al. (1995). Paroxetine in the treatment of panic disorder. British Journal of Psychiatry, 167(3), 374–397.

Rosenbaum, J. F., Fava, M., Hoog, S. L., Ascroft, R. C., & Krebs, W. B. (1998). Selective serotonin reuptake inhibitor discontinuation syndrome: A randomized clinical trial. Biological Psychiatry, 44(2), 77–87.

Schmidt, M. J., Fuller, R. W., & Wond, D. T. (1988). Fluoxetine, a highly selective serotonin reuptake inhibitor: A review of preclinical studies. British Journal of Psychiatry, 153(3), 40–46.

Stahl, M. M. S., Lindquist, M., Pettersson, M., Edwards, I. R., Sanderson, J. H., Taylor, N. F. A., et al. (1997). Withdrawal reactions with selective serotonin re-uptake inhibitors as reported to the WHO system. European Journal of Clinical Pharmacology, 53(3–4), 163–169.

Tharp, V., Burns, M., & Moskowitz, H. (1981). Development and field test of psychophysical tests for DWI arrest. (DOT HS 805–864). Washington, DC: U.S. Department of Transportation, NHTSA.

Young, A., & Haddad, P. (2000). Discontinuation symptoms and psychotropic drugs. Lancet, 355(9210), 1184.

Zajecka, J., Tracey, K. A., & Mitchell, S. (1997). Discontinuation symptoms after treatment with serotonin reuptake inhibitors: a literature review. Journal of Clinical Psychiatry, 58(7), 291–297.

Henry A. Spiller, MS, DABAT, DABFE, FACFEI, is board certified in Toxicology and the Director of a certified regional poison center, with more than 20 years clinical experience. He has authored more than 180 toxicology related publications, including peer-reviewed medical/scientific journals, comprehensive toxicology textbooks, and scientific abstracts. He has more than a decade of experience in training toxicologists and specialists in poison information and has directed, as principal investigator, more than 35 multi-center national studies in toxicology. He has made toxicology-related presentations at scientific meetings in North America, South America, and Europe and has presented evidence as an expert in numerous state and federal courts on toxicology related subjects.

Tama Sawyer, PharmD, is a Certified Specialist in Poison Information with more than 20 years clinical experience at a regional poison center.

Fall 2007 THE FORENSIC EXAMINER

THE FORENSIC EXAMINER Fall 2007

Table 1: SSRI and DAA Medications

Generic Drug Name Brand Name Drug Class Elimination Half-life Starting Dose Dosing Range

Escitalopram

Citalopram

Fluoxetine

Fluvoxamine

Paroxetine

Sertraline

Duloxetine

Venalfaxine

Lexapro

Celexa

Prozac

Luvox

Paxil

Zoloft

Cymbalta

Effexor

SSRI

SSRI

SSRI

SSRI

SSRI

SSRI

DAA

DAA

22–32 hours

33–37 hours

70 hours

17–23 hours

15–22 hours

24–27 hours

11–16 hours

5 hours

10mg

20mg

20mg

50mg

10mg

50mg

20mg

75mg

10–20mg

20–60mg

20–60mg

50–300mg

10–50mg

50–200mg

20–60mg

75–375mg

Cognitive Impairment Effects

• Agitation
• Anxiety
• Confusion
• Depersonalization/detachment
• Electric shock-like sensations
• Impaired concentration
• Irritability
• Short-term memory impairment

(Table complied from references: Black, Shea, Durson, & Kutcher, 2000; Campagne, 2005; Coupland, Bell, & Potokar, 1996; Leiter, Nierenberg, Sanders, & Stern, 1995; Michelson et al., 2000; Rosenbaum, Fava, Hoog, Ascroft, & Krebs, 1998; Stahl et al., 1997; Young & Haddad, 2000; Zajecka, Tracey, & Mitchell, 1997)

Table 2: Clinical Effects Reported with Antidepressant Withdrawal Syndrome

Motor Impairment Effects

• Blurred vision
• Dizziness/lightheaded/vertigo
• Gait instability
• Incoordination or impaired coordination
• Jerking eye movements
• Loss of balance
• Tremor
• Visual disturbances

Other Effects

• Diarrhea
• Chills
• Headache
• Insomnia
• Myalgia
• Nausea/vomiting
• Parathesias
• Sleep disturbances
• Suicide thoughts or behavior
• Sweating
• Tinnitus (ringing in the ears)
• Vivid dreams or nightmares

Fall 2007 THE FORENSIC EXAMINER

THE FORENSIC EXAMINER Fall 2007 - published by Dr. Robert OBlock

Eyewitness Memory in Context: Toward a Systematic Understanding of Eyewitness Evidence

Toward a Systematic Understanding of Eyewitness Evidence

Abstract

Eyewitness identification research has typically been focused either on isolated specific factors or on more broadly defined and more ecologically valid contexts that occur in more realistic but less-controlled crime simulations. However, a paucity of studies have addressed both controlled and realistic contexts, investigating specific factors systematically in context. In the present study, researchers have addressed the effects of the following circumstances on memory: stimulus complexity, gender of assailant, gender of respondent, presence of weapons, clothing and physical characteristics of assailants, peripheral sources of hazard, and seeing perpetrators in lineups. Standardized contexts were used to strengthen experimental controls. Results indicated that eyewitness memory, even under idealized conditions, was highly unreliable, both for perpetrator characteristics and for other aspects of the crime scene, including weapons and peripheral sources of hazard. These results provide important information about the elements of eyewitness testimony that are most likely to yield difficulties in both investigative and courtroom settings.

THE FORENSIC EXAMINER Fall 2007

Fall 2007 THE FORENSIC EXAMINER

This article is approved by the following for continuing education credit:

(ACFEI) The American College of Forensic Examiners International provides this continuing education credit for Diplomates.

(CFC) The American College of Forensic Examiners International provides this continuing education credit for Certified Forensic Consultants.

(APA) The American College of Forensic Examiners International is approved by the American Psychological Association to sponsor continuing education for psychologists. ACFEI maintains responsibility for this program and its content.

By Matthew J. Sharps, PhD, DABPS, FACFEI; Adam B. Hess, MA; Hilary Casner; Bethany Ranes, BA; and Jenna Jones, BA

Key Words: eyewitness memory, recognition memory

Over the past century, numerous studies have addressed eyewitness identification. Many sophisticated studies have addressed individual factors of importance, such as exposure time, suspect race, witness gender, or weapon presence (e.g., Narby, Cutler, & Penrod, 1996), typically in isolation. Such studies of isolated variables have been designed to improve experimental control. However, isolating such critical factors from their contexts, while increasing experimental control, has typically reduced ecological validity (for review, see Sporer, Malpass, & Koehnken, 1996; also, see Kassin, Tubb, Hosch, & Memon, 2001).

Other research has been directed at field studies, video, or live simulations of crime events. However, these studies, which improve on ecological validity, are necessarily less controlled (Morgan et al., 2004) and, consequently, are more difficult to interpret. There is a lack of systematic research on eyewitness testimony that bridges the gaps between isolated variables with better experimental controls and more realistic ecological variables with better validity. Additionally, whether an isolated-variable focus or a more ecological approach, there has been little research on eyewitness memory for forensically important elements other than identification of persons (elements such as recall of weapons and peripheral sources of hazard) (e.g., Sharps, Barber, Stahl, & Villegas, 2003; Villegas, Sharps, Satterthwaite, & Chisholm, 2005).

The integration of experimental control with more realistic environmental validity formed the foundation for the studies reported in this research. The experiments described in this research were designed to enhance the development of a systematic contextual understanding of eyewitness memory, which would help bridge the gap between isolated variables in experimentally controlled designs and environmental variables that are more realistic, but less controlled. Also, the present research was designed to address the broader context of eyewitness memory to include important inanimate elements of crime scenes while identifying the narrower specifics for each individual to get the highest degree of experimental precision possible.

In previous studies, Sharps et al. (2003) and Villegas et al. (2005) utilized this integrated tradition of addressing relatively ecologically valid contexts in experimentally controlled environments—in the important, but hitherto neglected, areas of weapon and vehicle identification. These studies were conducted under conditions of ideal lighting, exposure time, and freedom from contextual distraction. Even under these ideal conditions, which would be considerably diminished under the real-world conditions of a typical crime-scene, eyewitness memory was shockingly poor.

In our study of weapon identification (Sharps et al., 2003), response rates for semi-automatic pistol identification were correct in fewer than half the cases. More familiar handgun types were better recognized than less familiar types, but even familiar revolvers were recognized correctly only 43% of the time. Even assault weapons, which are used less frequently in crimes but are larger in size and have greater complexity of features and, consequently, are subject to a higher level of feature-intensive processing (Sharps, 2003; Sharps & Nunes, 2002), were correctly recognized less than three-quarters of the time. These data strongly suggest appreciable reconfiguration of memory for weapons after initial encoding at the given crime scene.

A similar study of vehicle identification (Villegas et al., 2005) yielded even poorer results. Again under idealized conditions, vehicles were identified correctly, on average, only one quarter of the time.

In Villegas et al.’s study (2005), vehicle color was more important in the generation of errors than vehicle model. This result was consistent with the Gestalt/Feature-Intensive Processing (G/FI) theory of visual cognition, which has proven useful in several areas of eyewitness memory research (Sharps, 2003; Sharps et al., 2003; Sharps & Nunes, 2002). Color, an identifiable feature of an object that may readily be processed linguistically, was more important in the generation of errors than was the vehicle model, which depends on the less linguistically-accessible shapes of the various structural elements of the given vehicle body type (see Sharps & Nunes).

The results of this research may be helpful in explaining such apparent anomalies as occurred in the Washington sniper case, in which the suspect vehicle, a dark-blue Chevrolet Caprice, was apparently misidentified by multiple witnesses as a white or cream-colored van (Blades, 2005). In this case, of course, neither color nor vehicle model were particularly helpful to witness memory. The repetition of the error is explicable in view of the relatively poor performance of witnesses in our laboratory situation, in which factors of darkness, brief exposure, occlusion, movement, and perceived danger had not been present. In these studies, memory for vehicles and for weapons was reconfigured in young, healthy witnesses to an extent that reliable eyewitness identification was unlikely.

The fact that such reconfiguration of memory occurs has been known for more than 70 years. Bartlett (1932) showed that memory is not the static, videotape-like system of popular imagination. Rather, memories become reconfigured in three primary ways. First, memories become shorter and more abbreviated. Second, details are lost, leaving a general representation upon which information obtained after the fact may act to alter elements of initial memory that may or may not have been correct in the first place. Finally, personal belief can alter memory significantly in both the visual and verbal realms. Bartlett showed that custom and cultural beliefs significantly reconfigured British subjects’ memories of Native American stories and that relatively abstract figures were recalled by respondents as specific, meaningful pictures of everyday objects if suggested to be such by the experimenter. Modern work in several venues has confirmed the major points originally described by Bartlett (e.g., Ahlberg & Sharps, 2002; Bergman & Roediger, 1999).

Research in G/FI theory has shown that these various phenomena may be encapsulated along a single processing dimension (Sharps, 2003; Sharps & Nunes, 2002). People in eyewitness situations typically encode a given original memory in a gestalt manner, with little attention to details that might assist in making a correct identification.

However, as the witness reviews the given memories over time, especially under circumstances in which others such as attorneys and investigators are directing and framing the viewpoint from which the events are considered, reviewed, and reported, the resultant feature-intensive analysis will process both actual/true details as well as details that have been derived from a reconfigurative process or from post-event suggestions. As Bartlett demonstrated, such details may readily be fabricated wholly unconsciously on the part of the witness from vague impressions, post-event information, or other sources. Thus, researchers can now explain the respondents’ tendencies to focus on feature-intensive factors such as vehicle color or on the greater number of identifiable features presented by a large assault weapon than by a small, simple handgun. Witnesses may search their memories for veridical features of the given crime situation, but then focus instead on inconsequential, inaccurate, or even accidentally fabricated elements that alter their memories further from the underlying genuine memory stimuli.

What happens to eyewitness memory in a context where features and details must be sorted and separated from visual situations with differing elements such as weapon presence and complexity? The experiments reported herein are initial attempts to cohere variable-by-variable studies of the variable components of eyewitness memory typically addressed solely in isolation, with more ecologically valid but less controlled studies employing simulated live or video-based crime scenes. In this initial effort, researchers employed high-quality digital photographs of ecologically valid crime scenes developed under the advice and supervision of expert senior field-training officers of the Fresno, California, Police Department. These officers were highly experienced in tactical realities and in the sorts of situations encountered by witnesses and officers on the street.

The photographs employed in these studies depicted a potentially violent crime scene in which either a male or a female perpetrator appeared armed with a Beretta handgun. The scene was either simple, sparse in terms of potentially distracting objects, or complex, including a victim being threatened by an armed perpetrator and typical street clutter. Peripheral sources of hazard were also included in the complex scenes. Researchers included in the complex scene an explicit explosive device (i.e., a disarmed and hollowed-out surplus hand grenade, which, from outward appearance, could not be distinguished from a live weapon) and a potentially implicit explosive device (i.e., a military-surplus ammunition box which may or may not have contained live explosives, but which was clearly out of place in the street scene and was placed next to the hand grenade, near the perpetrator). These crime elements were included because such weapons and ambush tactics have become increasingly important in real-world criminal and terrorist operations (Gelles, 2006).

For the sake of control in the case of weapon identification, in one full set of conditions (either a simple or complex context, and each with either male or female perpetrator), the Beretta was replaced by a power screwdriver, which the perpetrator might have been pointing or waving for emphasis in a non-lethal argument with the victim.

The conditions for all scenes involved uniformly excellent lighting (strong sunlight), extended exposure time, and the relative comfort of witnesses being seated 10–20 feet from a standard white movie screen, which they faced and on which the given scene was projected. There was no movement or occlusion of important elements of the scene, and of course, there was an absence of personal danger. As in our previous work (Sharps et al., 2003; Villegas et al., 2005), these idealized conditions were selected with the knowledge that an actual crime scene might well involve uncertain lighting and potentially occluded conditions and would typically result in poorer performance of eyewitnesses because of established dynamics of human visual cognition (e.g., Narby et al., 1996; Spoehr & Lehmkule, 1982).

Method

The participants in this study were 149 women (mean age 19.86 years, SD = 2.48) and 49 men (mean age = 21.10 years, SD = 4.59) recruited from freshman psychology classes at California State University, Fresno. Gender proportions reflect the proportions of the classes. Also, this population was generally younger and probably in better health than the population at large. A Snellen test of visual acuity was performed, and all respondents possessed at least 20/40 eyesight corrected or uncorrected. Each respondent viewed only one scene (simple or complex, with a male or female perpetrator either armed or holding the power tool).

In real-world eyewitness identification situations in general, exposures to critical stimuli are frequently brief and fragmented. Witnesses may be under stress and may be operating under elevated levels of arousal. Also, elements that might be important for later identification may actually be obscured in real crime situations by vehicles, buildings, curbs, or other contextual features. Further research should address eyewitness memory under systematically varied conditions of these critical parameters, and efforts along these lines are currently in progress in this laboratory. However, in this preliminary research, researchers sought to evaluate identification under ideal conditions and to establish baseline data as outlined above. Therefore, the condition of an extended exposure time was imposed—a full 5 seconds. Law enforcement experts suggest that, generally, a firearm assault situation, such as the one depicted in this study, tends to develop rapidly and may result in a violent conclusion in literally less than a second (e.g., Moore, 2006; Montejano, 2005; Tietjen, 2005). Therefore, respondents in this research had substantially more than the typical period of observation and processing time.

In order to evaluate witness performance, the aid of senior, experienced Fresno Police field training officers were enlisted to produce a realistic police interview focused on the scenes viewed by respondents. The interview administered requested information on the perpetrator’s dress, physical characteristics (as both general verbal descriptions and as specific numerical estimates of height, weight, and age), weapon type if any, and the presence of other sources of hazard in the scene. This information was collected via multiple methods for each topic. Respondents were scored on each item in an objective scoring system from 1 to 3: 3 reflected a correct answer, 1 reflected an incorrect answer, and 2 reflected uncertainty or an answer too vague to be of use.

These scores were combined and summed into specific indices: a clothing index (composed of 3-point scales for hat, coat, shirt, and shoes), and a physical characteristics index (composed of 3-point scales for complexion, facial hair, marks or tattoos, height, weight, and age). Numerical estimates for the latter three elements of this index were also obtained, although these were not entered into the combined score to avoid potential redundancy. Finally, there was an index of weapon characteristics (3-point scales on whether the respondent was armed, with what type of weapon generally, and then requesting a specific description of the firearm in question).

These combined indices were subjected to analysis of variance against four independent variables: the complexity of the scene; the gender of the perpetrator; whether or not the perpetrator was actually armed or carried the power screwdriver; and the gender of the witness.

A second study employing a sample of 47 college students (thirty-one females, mean age 25.68, years, SD = 7.44, and sixteen males, mean age 23.38 years, SD =3.14), was conducted to investigate standard line-up identification under the conditions provided by the same scenes described above. To replicate typical and realistic crime scenes, only the scenes involving the armed male perpetrator were employed in the second study. Witnesses were exposed to the given scene for the usual 5-second exposure, followed by administration of a “six-pack” photographic lineup recognition test, to which the sample responded between 10 and 15 minutes after termination of the exposure.

The lineup was administered according to Department of Justice (DOJ) guidelines (1999). In the lineups, the perpetrator was placed at either position 3 or 5. A simultaneous lineup procedure was chosen because this remains the most commonly employed technique in actual criminal investigations (Wogalter, Malpass, & Burger, 1993), despite research that indicates sequential lineups are typically more accurate (e.g., MacLin, Zimmerman, & Malpass, 2005; Wells, 1993; Wogalther, Malpass, & McQuiston, 2004).

Finally, all respondents in both experiments completed the Conners Adult ADHD Rating Scales (CAARS) (Conners, Erhardt, & Sparrow, 1999) and the Dissociative Experiences Scale (DES) (Carlson et al., 1991). These scales were included to explore the possibility that symptoms of attention deficit and dissociation at levels found in a general, non-diagnosed population and falling below the threshold of identifiable clinical significance might influence performance in eyewitness identification. These specific factors were analyzed, as they have been shown in previous research to influence performance in other areas of G/FI processing (e.g., Sharps, Matthews, & Asten, 2006; Sharps, Price-Sharps, Day, Villegas, & Nunes, 2005).

Results and Discussion

Neither DES scores nor scores on any subscales of the CAARS were significantly predictive of performance on any index or measurement in either of these experiments. Within the present research framework, and with symptomatology at clinically non-significant levels, eyewitness abilities were influenced minimally, if at all, by attention deficit or dissociative anomalies. These results do not, of course, speak to clinically significant disorders or syndromes or to other possible frameworks of research.

Specific memory results for each index described above are as follows:

Memory for Clothing

The average combined score for witness recall of perpetrator clothing was a respectable 9.64 out of 12 (SD = 1.67), an accuracy of 80.3%. The effect of scene complexity was significant, F (1,182) = 4.60, p = .033, but modest; complex scenes resulted in only 3.3% less accuracy than did simple (sparse) scenes. The effect of perpetrator gender was also significant, F (1,182) = 12.55, p < .001, with the female perpetrator’s clothing being described 12.6% better than that of the male on average. This effect interacted significantly with the effect of scene complexity, F (1,182) = 3.93, p = .049. The presence or absence of a weapon was not significant on clothing description, but the gender of the witness was, F (1,182) = 4.08, p = .045. This effect should be interpreted with caution because of the disparity in numbers of the two sexes, but within this research framework, women were 7.46% better than men on average at describing perpetrator clothing.

Memory for Physical Characteristics

The average combined score for witness recall of perpetrator physical appearance was less impressive than that for clothing—only 12.71 out of a possible 18 points (SD = 1.81), an accuracy of 70.6%. For this index, the effects of scene complexity, witness gender, and weapon were non-significant; the only significant variable was gender of perpetrator, F (1,182) = 12.64, p < .001, with the appearance description scores for the female perpetrator 11.97% higher on average than those of the male.

As noted above, in addition to the questions requesting verbal descriptions of height, weight, and age, numerical estimates were sought from witnesses as well. There was no identifiable correlation, significant or otherwise, between numerical or verbal estimates. In other words, a descriptive term like heavy, thin, or tall had no identifiable relationship with numerical estimates of the same quantities. Further research will be needed to understand the mechanisms by which witnesses arrived at these apparently unrelated qualitative and quantitative descriptions. However, if confirmed in other research, this finding may have important implications for police interview techniques. For example, respondents may be better at making general, qualitative descriptions of persons than they are at attempting to convert their observations into realistic quantitative estimates. How law enforcement officers elicit such information (qualitatively or quantitatively) may result in differences in the utility of such information in searches, investigations, and courtroom proceedings.

Memory for Weapons and for Peripheral Sources of Hazard.

In contrast to the data concerning the physical description of the perpetrator, the independent variables of scene complexity, perpetrator gender, and gun-versus-screwdriver all resulted in significant effects on identification of the weapon carried by the perpetrator. Also significant were the interaction of complexity and perpetrator gender and the interaction of these factors with the gun/screwdriver variable [F values, respectively, were F (1,182) = 4.18, p = .042; F (1,182) = 4.053, p = .046; F (1,182) = 242.69, p < .001; F (1,182) = 7.50, p = .007; and F (1,182) = 8.17, p = .005].

The effect of witness gender was not significant. Average performance across conditions was not impressive, with a mean score of 6.20 (SD = 2.63) out of a possible 9 points, producing an average witness accuracy of 68.9%. The simple scene yielded better performance than the complex scene by 4.12%. The male perpetrator resulted in better performance than the female by 22.28%. Further, the gun condition was massively superior to the screwdriver condition, by 211%.

This gun condition results warranted further investigation. In the screwdriver condition, out of 103 respondents, 92 were in error, believing the screwdriver to have been, in fact, a firearm. Only five witnesses had been uncertain as to what they had seen, and a mere six correctly identified the power tool. It should be reiterated that this result was obtained under conditions of ideal lighting and exposure, as well as an exposure period several times longer than typical for real-world criminal activity.

Even with enhanced light and time, most witnesses identified the tool as a gun. This result may prove useful in explaining the large numbers of cases in which civilians and police mistake an innocuous object for a firearm. Rather than having anything to do with witness or law enforcement duplicity, such errors may frequently derive from typical characteristics of human visual cognition when witnesses are faced with this type of situation (see Sharps et al., 2003). It is important to develop a better empirical understanding of the types of conditions under which such errors are most prevalent.

Identification of peripheral sources of hazard was also unexpectedly poor. Only a single respondent, out of 94, identified the hand grenade, even though the grenade was in plain sight and viewed under the optimized observation conditions described above. Not a single individual identified the ammunition box as a potential source of hazard, even though it was placed close to the hand grenade and was clearly an anomalous object in a normal street scene.

In view of the terrorist threats currently confronting law enforcement and military authorities in much of the world and the relative reliance of terrorists on ambush tactics and pre-placed improvised explosive devices (e.g., Gelles, 2006), the failure to detect a grenade hazard clearly highlights the need for a better understanding of witness, bystander, and professional perceptual and cognitive responses to such devices. This is especially important in view of the fact that such devices are not normally placed in plain sight, as they were in the present study.

On a train or in a crowded street, observation of such peripheral sources of explosive hazard prior to their detonation and the recognition of an anomaly—something that simply should not be there—is likely to come from a law enforcement officer, a security officer, or a particularly alert civilian. Given the poor performance of respondents in this study to such hazards placed in plain sight and under optimal viewing conditions, more research on the topic of observation, detection, and interpretation of anomalous threatening devices is clearly needed.

Lineup Performance

This experiment required witnesses to respond to a typical police lineup, only 10 to 15 minutes after viewing the simple or the complex scene of the armed male perpetrator under ideal conditions. The sole visual transformation required of the respondents involved viewing the perpetrator in profile in the crime scenes and viewing the perpetrator and foils full-face in the lineup photographs. Though there appear to be no current statistics on this subject, it seems that in a typical, actual crime situation, witnesses rarely have the opportunity to gaze full-face on a suspect. Actual perpetrators are typically in motion, frequently with their faces occluded by a partial disguise, such as a hood, cap, or even stocking mask, and conditions are seldom optimal (e.g., Narby et al., 1996). Thus, this simple transformation of the view of the alleged perpetrator under optimized laboratory conditions would seem to pose little challenge compared to the use of lineups in real-world forensic practice (e.g., DOJ, 1999).

However, the results of this experiment led to little cause for optimism in the realm of alleged perpetrator identification. Out of 47 respondents, only 5 were able to identify the perpetrator correctly from a standard simultaneous lineup. Position 5 (central, bottom row) was slightly more likely to result in a correct identification than Position 3 (more visually peripheral). However, the level of identification observed here was sufficiently poor as to render miniscule the position effect, and, essentially, render moot this picture-placement finding. Of the five correct identifications, four of the five came from the simple condition. Only one individual in the complex and more realistic condition was able to make the identification correctly.

These results are sufficiently close to the statistical “floor” as to defy inferential statistical testing. The data clearly indicate that, at least within the conditions of this research, at best, only about 10% of witnesses can be anticipated to be correct in their identifications. Furthermore, accuracy is probably likely to be lower in more complex, and hence more realistic, visual situations. These results may at first seem to fly in the face of some schools of conventional wisdom on this subject. For example, human visual recognition memory was shown to be quite efficient in a series of classic studies, especially for detailed pictures (e.g., Nelson, Metzler, & Reed, 1974), but performance declined with shorter exposure times (e.g., Loftus & Bell, 1975). However, these studies required recognition of pictures in their entirety, rather than the recognition of abstracted elements of original encoding situations involving visual transformations, which is typical of lineup procedures.

Other studies have, of course, found recall or recognition-enhancing effects of, for example, instructional manipulations (e.g., Cutler, Penrod, & Martens, 1987), which may enhance lineup memory (in the case of the Cutler et al. study, to 44% accuracy). However, in the absence of such manipulations, and with only a single visual change in the aspect of the individual to be identified, the present results add to the growing body of information suggesting that person identification, even when obtained from properly conducted police lineups (DOJ, 1999), must be viewed with extreme caution by law enforcement and judicial personnel.

Summary and Conclusions

As anticipated from previous research (e.g., Narby et al., 1996; Sporer, Malpass, & Koehnken, 1996; Sharps et al.; Villegas et al., 2005), levels of eyewitness performance in person description, weapon description, and person identification were generally low. When a contextual systematic assessment of specific factors involved in these effects was conducted, more complex (and hence more realistic) scenes resulted in diminished performance compared to simpler situations. Witnesses generally reported an innocuous object (i.e., the screwdriver) to have been a handgun, even under the ideal viewing conditions employed here. Under typical, approved lineup conditions, recognition of a perpetrator seen in context was effectively at a statistical floor. Peripheral sources of hazard, even when placed in plain view, generally went unnoticed and unreported. Finally, the viewing of a female perpetrator, as opposed to a male, improved person description significantly but reduced weapon recognition.

An immediate limitation on the present research is noted. The use of a single male and female perpetrator in these studies obviously does not allow broad general conclusions about perpetrator gender and identification. A more exhaustive accounting of this effect would require depictions of a large number of individuals of both sexes, systematically varied according to race, physique, perceived attractiveness, and other characteristics. Such an effort would require a substantial long-term research project devoted to this question alone, well beyond the scope of this preliminary research. There must be, however, limitations to the generalized results of such a broad effort, as any given real-world perpetrator might possess characteristics that differed significantly from those evaluated.

For the present, there is a reasonable, parsimonious working explanation for the significant effects of perpetrator gender observed here. Although women do commit violent crimes, the vast majority are committed by men. Confronting a female perpetrator may reduce processing and performance, even in seasoned combatants and law-enforcement officers (e.g., Grossman, 1996; Kessler, 2002). The authors suggest that the witnesses’ patterns of attention and cognitive resources may have been altered by the surprise or the violation of expectations, engendered by the depiction of the female perpetrator. The higher average reportage of the female perpetrator’s clothing and physical characteristics than those of the male may speak to this effect. Attention and processing resources were drawn to her as an unexpected stimulus, resulting in the superior description of her clothing and body per se.

However, with better identification of the female perpetrator, resources were reciprocally drawn away from other elements of the scene, such as the gun, which might have been more expected in the hands of a male. As a result, the study suggests that weapon identification was superior with the male perpetrator.

The role of expectations may also help explain the tendency of witnesses to report the innocuous power screwdriver as a firearm. There may have been a tacit expectation that a given object, pointed by one individual at another, was in fact a weapon. This expectation-based reconfiguration (see Bartlett, 1932; Ahlberg & Sharps, 2002) could have resulted in the potentially vast witness misperception observed in this research. However, these impressions are conjectural at present. A significant body of future research will be needed to elucidate the mechanisms of these effects.

The gender of the witness had a significant effect on clothing description. Women’s performance exceeded that of men on average. However, and perhaps contrary to expectations, no gender differences were observed in weapon identification, physical description, or lineup recognition of persons. Because of the extremely poor performance of witnesses of both sexes, lineup recognition could not even be analyzed statistically.

Also, there was also no evidence of an effect, in this civilian witness population, of familiarity with weapons on witnesses’ ability to identify them. One might, however, expect such an effect with trained law-enforcement or military personnel, who are familiar with the idiosyncratic features of many weapons, including the standard police Beretta used in these studies. Finally, tendencies toward attention deficit and dissociation at subclinical levels did not influence eyewitness performance.

In aggregate, these studies attest to the importance of the empirical evaluation of eyewitness memory in systematically-varied context. The combined effects observed here further add to the growing body of evidence indicating the necessity of viewing eyewitness evidence with extreme caution. Contrary to beliefs often observed to prevail in courtroom proceedings, eyewitness identifications of persons, weapons, and peripheral sources of hazard in crime scenes are unlikely to be highly accurate, especially under the relatively brief conditions of exposure, the high levels of arousal, and the poor viewing conditions typical of real-world crime scenes.

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Acknowledgements

The authors wish to thank Chief of Police Jerry Dyer of the Fresno Police Department and the staff and field training officers of the Fresno Police Department for giving of their time and expertise and for their continued and very generous assistance, advice, and support of this research. They would also like to thank Officer Scott Larson, Los Angeles Police Department and Amy Neff, Morgan Goodwin, and Randy Vaughn-Dotta for their excellent help in the preparation of the materials for this research. The research, views, and opinions presented in this article are those of the authors and do not necessarily reflect the views or opinions of the Fresno or Los Angeles Police Departments or their chiefs, staffs, officers, or employees.

About the Authors

Matthew J. Sharps, PhD, DABPS, FACFEI, is professor of psychology at California State University, Fresno, and adjunct faculty member at Alliant International University. He received his MA (clinical psychology) from UCLA and MA and PhD (psychology) from the University of Colorado. He is the author of numerous articles and papers on visual cognition and related topics as well as the book Aging, Representation, and Thought: Gestalt and Feature-Intensive Processing (2003, Transaction Publishers). He has consulted on issues of eyewitness identification in more than 160 criminal cases.

Adam B. Hess, MA, is a lecturer in Criminology at California State University, Fresno, and a doctoral candidate in forensic clincical psychology at Alliant International University, Fresno.

Bethany Ranes, BA, is a doctoral candidate in Forensic Clinical Psychology at Alliant International University, Fresno.

Jenna Jones, BA, is a doctoral candidate in Forensic Clinical Psychology at Alliant International University, Fresno.

Hilary Casner, BA, is a graduate student in psychology at the University of Arkansas.

Factors Leading to Wrongful Convictions

The most common factors leading to wrongful convictions that were found in the first 130 DNA exonerations.

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False Confessions (35)

Microscopic Hair Comparison Matches (21)

Informants/Snitches (21)

DNA Inclusions at Time of Trial (3)