Improving juror sensitivity to specific eyewitness factors: judicial instructions fail the test.

A recent New Jersey Supreme Court decision recognized the difficulty jurors have with evaluating eyewitness evidence. This decision resulted in the development of instructions that highlight factors affecting identification accuracy. Research has explored the efficacy of eyewitness instructions for improving jurors' decision-making. Jurors in these studies are typically presented with identifications that manipulate multiple witnessing and identification conditions simultaneously, making it difficult to ascertain whether instructions help jurors evaluate any one eyewitness factor. We conducted two experiments to examine how jurors evaluate eight individual eyewitness factors with and without instructions. Across both experiments, none of the individual eyewitness factors nor instructions influenced jurors. Instructions only assisted jurors when multiple eyewitness factors were collapsed to create either extremely good or poor-quality identifications. These findings contribute to the long history of jurors remaining largely insensitive to the nuances of witnessing and identification conditions. Current safeguards may only assist jurors under limited circumstances.

New signal detection theory-based framework for eyewitness performance in lineups.

OBJECTIVES: Eyewitness research has adapted signal detection theory (SDT) to investigate eyewitness performance. SDT-based measures in yes/no tasks fit well for the measurement of eyewitness performance in show-ups, but not in lineups, because the application of the measures to eyewitness identifications neglects the role of fillers. In the present study, we introduce a SDT-based framework for eyewitness performance in lineups-Multi-d' Model. METHOD: The Multi-d' model provides multiple discriminability measures which can be used as parameters to investigate eyewitness performance. We apply the Multi-d' model to issues in eyewitness research, such as the comparison of eyewitness discriminability between show-ups and lineups; the influence of lineup bias on eyewitness performance; filler selection methods (match-to-description vs. match-to-suspect); eyewitness confidence; and lineup presentation modes (simultaneous vs. sequential lineups). RESULTS: The Multi-d' model demonstrates that the discriminability of a guilty suspect from an innocent suspect is a function of discriminability involving fillers; and underscores that the decisions that eyewitnesses make in lineups can be regarded from two perspective-detection and identification. CONCLUSIONS: We propose that the Multi-d' model is a useful tool to understand decisionmakers' performance in a variety of compound decision tasks, as well as eyewitness identifications in lineups. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Research-Based Instructions Induce Sensitivity to Confession Evidence.

Evidence is mixed on whether or not laypersons have sufficient knowledge of false confession risk factors. Procedural safeguards such as judicial instructions may assist jurors who are unable to effectively evaluate confession evidence. Participants were randomly assigned to one of five conditions that varied in the quality of a confession and the presence of instructions on coercive interrogation techniques. The results indicate that instructions induce sensitivity by altering verdict decisions and perceptions of evidence strength and confession voluntariness in line with the quality of the interrogation. Furthermore, the presence of instructions in low-quality interrogations resulted in participants completely discounting the confession. These findings suggest that research-based instructions on coercive interrogation techniques may be an effective safeguard against the use of potentially unreliable confession evidence.

Fair lineups are better than biased lineups and showups, but not because they increase underlying discriminability.

Receiver Operating Characteristic (ROC) analysis has recently come in vogue for assessing the underlying discriminability and the applied utility of lineup procedures. Two primary assumptions underlie recommendations that ROC analysis be used to assess the applied utility of lineup procedures: (a) ROC analysis of lineups measures underlying discriminability, and (b) the procedure that produces superior underlying discriminability produces superior applied utility. These same assumptions underlie a recently derived diagnostic-feature detection theory, a theory of discriminability, intended to explain recent patterns observed in ROC comparisons of lineups. We demonstrate, however, that these assumptions are incorrect when ROC analysis is applied to lineups. We also demonstrate that a structural phenomenon of lineups, differential filler siphoning, and not the psychological phenomenon of diagnostic-feature detection, explains why lineups are superior to showups and why fair lineups are superior to biased lineups. In the process of our proofs, we show that computational simulations have assumed, unrealistically, that all witnesses share exactly the same decision criteria. When criterial variance is included in computational models, differential filler siphoning emerges. The result proves dissociation between ROC curves and underlying discriminability: Higher ROC curves for lineups than for showups and for fair than for biased lineups despite no increase in underlying discriminability. (PsycINFO Database Record

Examining pretrial publicity in a shadow jury paradigm: issues of slant, quantity, persistence and generalizability.

The purpose of this study was to examine the influence of pretrial publicity (PTP) on mock juror decision making. Specifically, we examined the influence of quantity and slant of the PTP (proprosecution vs. prodefense), the persistence of PTP effects over time, and whether the PTP effects demonstrated in research laboratories would also occur in more naturalistic settings (generalizability). Using a shadow jury paradigm we examined these effects using a real trial as stimulus. Mock jurors included 115 jury-eligible community members who were naturally exposed to PTP in the venue in which the actual case occurred and 156 who were experimentally exposed. We found mock jurors were significantly influenced by both the slant and quantity of the PTP to which they were exposed, such that those exposed to proprosecution or prodefense PTP tended to render decision in support of the party favored in the PTP, and those exposed to greater quantities of PTP tended to be more biased. Additionally, PTP effects persisted throughout the course of the trial and continued to influence judgments in face of trial evidence and arguments. A finding of no significant difference in the effect of exposure slant between the naturally exposed and experimentally exposed samples provides support for the external validity of laboratory studies examining PTP effects. This research helps address some of the concerns raised by courts with regard to the durability of PTP effects and the application of laboratory findings to real world settings.

Forgetting the once-seen face: estimating the strength of an eyewitness's memory representation.

The fidelity of an eyewitness's memory representation is an issue of paramount forensic concern. Psychological science has been unable to offer more than vague generalities concerning the relation of retention interval to memory trace strength for the once-seen face. A meta-analysis of 53 facial memory studies produced a highly reliable association (r=.18, d=0.37) between longer retention intervals and positive forgetting of once-seen faces, an effect equally strong for both face recognition and eyewitness identification studies. W. A. Wickelgren's (1974, 1975, 1977) theory of recognition memory provided statistically satisfactory fits to 11 different empirical forgetting functions. Applied to the results of field studies of eyewitness memory, the theory yields predictions relevant to fact finders' evaluations of eyewitness credibility. A plausible upper limit for witness initial memory strength corresponds to a probability of .67 of being correct on a fair six-person lineup. Furthermore, not only can the percentage of remaining memory strength be determined for any retention interval, but this strength estimate can be translated into an estimated probability of being correct on a fair lineup of a specified size.

Death Penalty Decisions: Instruction Comprehension, Attitudes, and Decision Mediators.

A primary goal of this research was to empirically evaluate a set of assumptions, advanced in the Supreme Court's ruling in Buchanan v. Angelone (1998), about jury comprehension of death penalty instructions. Further, this research examined the use of evidence in capital punishment decision making by exploring underlying mediating factors upon which death penalty decisions may be based. Manipulated variables included the type of instructions and several variations of evidence. Study 1 was a paper and pencil study of 245 undergraduate mock jurors. The experimental design was an incomplete 4×2×2×2×2 factorial model resulting in 56 possible conditions. Manipulations included four different types of instructions, presence of a list of case-specific mitigators to accompany the instructions, and three variations in the case facts: age of the defendant, bad prior record, and defendant history of emotional abuse. Study 2 was a fully-crossed 2×2×2×2×2 experiment with four deliberating mock juries per cell. Manipulations included jury instructions (original or revised), presence of a list of case-specific mitigators, defendant history of emotional abuse, bad prior record, and heinousness of the crime. The sample of 735 jury-eligible participants included 130 individuals who identified themselves as students. Participants watched one of 32 stimulus videotapes based on a replication of a capital sentencing hearing. The present findings support previous research showing low comprehension of capital penalty instructions. Further, we found that higher instruction comprehension was associated with higher likelihood of issuing life sentence decisions. The importance of instruction comprehension is emphasized in a social cognitive model of jury decision making at the sentencing phase of capital cases.

The role of societal benefits and fairness concerns among decision makers and decision recipients.

Four experiments examined the role of costs and benefits versus procedural and distributive justice for procedural fairness and procedural evaluations among decision makers and decision recipients. Experiments 1 and 2 examined the responses of actual judges in a 2 (high versus low benefit) x 2 (search procedure conducted respectfully versus disrespectfully) randomized factorial. In both studies judges evaluated procedures differently than is typical among samples of decision recipients: outcome concerns strongly influenced both procedural evaluations and procedural fairness while procedural concerns such as voice and respect were minimally influential. Whereas fairness concerns continued to be important among these decision makers, outcome fairness was more influential than procedural fairness. Studies 3 and 4 varied role (authority versus subordinate), procedural respect, and societal benefits. Both experiments supported our predictions that procedural criteria would dominate the procedural evaluations of subordinates whereas outcome concerns such as societal benefits would dominate the procedural evaluations of authorities.

Eyewitness Evidence: Improving Its Probative Value.

The criminal justice system relies heavily on eyewitnesses to determine the facts surrounding criminal events. Eyewitnesses may identify culprits, recall conversations, or remember other details. An eyewitness who has no motive to lie is a powerful form of evidence for jurors, especially if the eyewitness appears to be highly confident about his or her recollection. In the absence of definitive proof to the contrary, the eyewitness's account is generally accepted by police, prosecutors, judges, and juries. However, the faith the legal system places in eyewitnesses has been shaken recently by the advent of forensic DNA testing. Given the right set of circumstances, forensic DNA testing can prove that a person who was convicted of a crime is, in fact, innocent. Analyses of DNA exoneration cases since 1992 reveal that mistaken eyewitness identification was involved in the vast majority of these convictions, accounting for more convictions of innocent people than all other factors combined. We review the latest figures on these DNA exonerations and explain why these cases can only be a small fraction of the mistaken identifications that are occurring. Decades before the advent of forensic DNA testing, psychologists were questioning the validity of eyewitness reports. Hugo Münsterberg's writings in the early part of the 20th century made a strong case for the involvement of psychological science in helping the legal system understand the vagaries of eyewitness testimony. But it was not until the mid- to late 1970s that psychologists began to conduct programmatic experiments aimed at understanding the extent of error and the variables that govern error when eyewitnesses give accounts of crimes they have witnessed. Many of the experiments conducted in the late 1970s and throughout the 1980s resulted in articles by psychologists that contained strong warnings to the legal system that eyewitness evidence was being overvalued by the justice system in the sense that its impact on triers of fact (e.g., juries) exceeded its probative (legal-proof) value. Another message of the research was that the validity of eyewitness reports depends a great deal on the procedures that are used to obtain those reports and that the legal system was not using the best procedures. Although defense attorneys seized on this nascent research as a tool for the defense, it was largely ignored or ridiculed by prosecutors, judges, and police until the mid 1990s, when forensic DNA testing began to uncover cases of convictions of innocent persons on the basis of mistaken eyewitness accounts. Recently, a number of jurisdictions in the United States have implemented procedural reforms based on psychological research, but psychological science has yet to have its fullest possible influence on how the justice system collects and interprets eyewitness evidence. The psychological processes leading to eyewitness error represent a confluence of memory and social-influence variables that interact in complex ways. These processes lend themselves to study using experimental methods. Psychological science is in a strong position to help the criminal justice system understand eyewitness accounts of criminal events and improve their accuracy. A subset of the variables that affect eyewitness accuracy fall into what researchers call system variables, which are variables that the criminal justice system has control over, such as how eyewitnesses are instructed before they view a lineup and methods of interviewing eyewitnesses. We review a number of system variables and describe how psychological scientists have translated them into procedures that can improve the probative value of eyewitness accounts. We also review estimator variables, variables that affect eyewitness accuracy but over which the system has no control, such as cross-race versus within-race identifications. We describe some concerns regarding external validity and generalization that naturally arise when moving from the laboratory to the real world. These include issues of base rates, multicollinearity, selection effects, subject populations, and psychological realism. For each of these concerns, we briefly note ways in which both theory and field data help make the case for generalization.

Mugshot exposure effects: Retroactive interference, mugshot commitment, source confusion, and unconscious transference.

More than 25 years of research has accumulated concerning the possible biasing effects of mugshot exposure to eyewitnesses. Two separate metaanalyses were conducted on 32 independent tests of the hypothesis that prior mugshot exposure decreases witness accuracy at a subsequent lineup. Mugshot exposure both significantly decreased proportion correct and increased the false alarm rate, the effect being greater on false alarms. A mugshot commitment effect, arising from the identification of someone in a mugshot, was a substantial moderator of both these effects. Simple retroactive interference, where the target person is not included among mugshots and no one in a mugshot is present in the subsequent lineup, did not significantly impair target identification. A third metaanalysis was conducted on 19 independent tests of the hypothesis that failure of memory for facial source or context results in transference errors. The effect size was more than twice as large for "transference" studies involving mugshot exposure in proximate temporal context with the target than for "bystander" studies with no subsequent mugshot exposure.

Fractional factorial designs for legal psychology.

Researchers considering novel or exploratory psycholegal research are often able to easily generate a sizable list of independent variables (IVs) that might influence a measure of interest. Where the research question is novel and the literature is not developed, however, choosing from among a long list of potential variables those worthy of empirical investigation often presents a formidable task. Many researchers may feel compelled by legal psychology's heavy reliance on full-factorial designs to narrow the IVs under investigation to two or three in order to avoid an expensive and unwieldy design involving numerous high-order interactions. This article suggests that fractional factorial designs provide a reasonable alternative to full-factorial designs in such circumstances because they allow the psycholegal researcher to examine the main effects of a large number of factors while disregarding high-order interactions. An introduction to the logic of fractional factorial designs is provided and several examples from the social sciences are presented.

Web-based research: methodological variables' effects on dropout and sample characteristics.

Previous research has made a beginning in addressing the importance of methodological differences in Web-based research. The present paper presents four studies investigating whether sample type, financial incentives, time when personal information is requested, table design, and method of obtaining informed consent influence dropout and sample characteristics (both demographics and measured attitudes). Undergraduates were less likely to drop out than nonstudents, and nonstudents offered a financial incentive were less likely to drop out than those offered no incentive. Complex tables, tables that were too wide, requests for personal information on the first page, and the imposing of additional informed consent procedures each provoked early dropout. As was expected, nonstudents and those presented with complex tables showed more measurement error and attitude differences. Asking for personal information and imposing additional consent procedures affected the demographic makeup, raising challenges to external validity.

A meta-analytic review of the effects of high stress on eyewitness memory.

In the past 30 years researchers have examined the impact of heightened stress on the fidelity of eyewitness memory. Meta-analyses were conducted on 27 independent tests of the effects of heightened stress on eyewitness identification of the perpetrator or target person and separately on 36 tests of eyewitness recall of details associated with the crime. There was considerable support for the hypothesis that high levels of stress negatively impact both types of eyewitness memory. Meta-analytic Z-scores, whether unweighted or weighted by sample size, ranged from -5.40 to -6.44 (high stress condition-low stress condition). The overall effect sizes were -.31 for both proportion of correct identifications and accuracy of eyewitness recall. Effect sizes were notably larger for target-present than for target-absent lineups, for eyewitness identification studies than for face recognition studies and for eyewitness studies employing a staged crime than for eyewitness studies employing other means to induce stress.

Studying pretrial publicity effects: new methods for improving ecological validity and testing external validity.

Although research examining the effects of pretrial publicity (PTP) on individuals' appraisals of a defendant and verdict decision making generally has been found to be internally valid, the external validity has been questioned by some social scientists as well as lawyers and judges. It is often proposed that the verisimilitude (or ecological validity) ofthe research should be increased in the service of increasing external validity; however, increasing verisimilitude can be costly in terms of both time and money. It is proposed that the Internet is a viable means of conducting PTP research that allows high verisimilitude without high costs. This is demonstrated with a study in which we used the Internet to examine PTP effects in an actual trial as it was taking place. Successful use of the Internet to conduct experimental research in other areas of psychology and law is discussed, as well as the importance of future research examining whether independent variables interact with methods in ways that undermine the generalizability of research findings.