In light of recent advances, this study updated a prior survey of eyewitness experts (S. M. Kassin, P. C. Ellsworth, & V. L. Smith, 1989). Sixty-four psychologists were asked about their courtroom experiences and opinions on 30 eyewitness phenomena. By an agreement rate of at least 80%, there was a strong consensus that the following phenomena are sufficiently reliable to present in court: the wording of questions, lineup instructions, confidence malleability, mug-shot-induced bias, postevent information, child witness suggestibility, attitudes and expectations, hypnotic suggestibility, alcoholic intoxication, the crossrace bias, weapon focus, the accuracy-confidence correlation, the forgetting curve, exposure time, presentation format, and unconscious transference. Results also indicate that these experts set high standards before agreeing to testify. Despite limitations, these results should help to shape expert testimony so that it more accurately represents opinions in the scientific community.

The effect on juror verdicts of judicial instructions to disregard inadmissible evidence was evaluated using meta-analysis. One hundred seventy-five hypothesis tests from 48 studies with a combined 8,474 participants were examined. Results revealed that inadmissible evidence (IE) has a reliable effect on verdicts consistent with the content of the IE. Judicial instruction to ignore the inadmissible evidence does not effectively eliminate IE impact. However, if judges provide a rationale for a ruling of inadmissibility, juror compliance may be increased. Contested evidence ruled admissible accentuates that information, resulting in a significant impact on verdicts. Suggestions for how the courts may mitigate the impact of inadmissible evidence more effectively are discussed.

Previous studies have shown that mock jurors are skeptical of alibi witnesses who are related to or even have a close social relationship with a defendant. The present project tested respondents' ability to recall their whereabouts for a particular date and time. It also provided the first descriptive data on a variety of alibi topics. The majority of individuals claimed to have an alibi witness for a given time and the majority of alibi witnesses were friends or family members. Hispanic participants relied more heavily on family to serve in an alibi witness capacity whereas non-Hispanic Whites relied more heavily on friends.

Two studies tested the impact of an alibi witness's relationship to a defendant on the perceived credibility of that witness. In the first study, 291 mock jurors estimated the frequency with which individuals would invent alibis, the frequency they themselves would do so, and the frequency of interpersonal contact among individuals of varying relationships. The degree of relationship between an alibi witness and a defendant remained a predictor of witness credibility when contact frequency was controlled. In the second study, 512 mock jurors were randomly assigned to case scenarios. Skepticism toward witnesses who are biologically or affinally related to a defendant was greater than skepticism toward a socially linked witness. Both studies supported predications from kinship theory and reciprocal altruism.

The impact of alibi testimony on juror decision making is not yet clear because it has been examined empirically infrequently. This study was designed to determine the impact of alibi witness' testimony, the impact of an alibi witness with a relationship in comparison to one without a relationship to the defendant, and the impact of an eyewitness' confidence on juror decision making. Results indicated that mock jurors acquit a defendant more often when an alibi witness with no relationship to the defendant testified on his behalf. Participants did not believe an alibi witness who had a relationship with the defendant even though the witness was not a family member. Implications for these results are discussed.