Safety in Numbers: A Policy-Capturing Study of the Alibi Assessment Process

You don't know: knowledge as supportive alibi evidence

Until now, supportive evidence for alibis has been conceptualised into two distinct types: witness and physical evidence. The present study examined whether knowledge, as a third type of supportive evidence, can contribute to the understanding of evidence for alibis. Three experiments were conducted in which police detectives, laypersons and undergraduate students were asked to evaluate four alibis with witness, physical or knowledge supportive evidence, or with no supportive evidence. The results from the three experiments show that knowledge evidence is equally believable as strong witness evidence. We also found that not all items of strong physical evidence are evaluated as equally strong and believable. We therefore suggest adjusting the criteria to determine the strength of physical evidence and conducting more research on knowledge evidence.

Credibility assessments of alibi accounts: the role of cultural intergroup bias

Research has shown that judges and jurors are influenced by suspect ethnicity and that they might discriminate against out-group suspects in making decisions. This study examined the tendency to favor in-group members, as predicted by social identity theory, in assessing alibi credibility. Forty Israeli-Jewish and 40 Israeli-Arab participants assessed the credibility of an alibi statement provided by a suspect who was either Israeli-Jewish or Israeli-Arab. Findings show that participants were more likely to believe the alibi when it was provided by an in-group suspect than by an out-group suspect, supporting intergroup bias in alibi credibility assessments. Practical and theoretical implications are discussed.

Alibi believability: Corroborative evidence and contextual factors

A disbelief in alibis is one contributor to wrongful convictions. One reason that triers-of-fact may disbelieve alibis is that they lack evidence to corroborate the whereabouts of the suspect at the time of the crime. Contextual factors, such as when the alibi was disclosed and what was the nature of the crime, can also affect alibi believability. This paper outlines two studies where mock jurors evaluated an investigation and trial description online and rated alibi believability, defendant character trait ratings, and verdicts. Both studies examined the impact of corroborative alibi evidence and the timing of the alibi disclosure. In addition, Study 1 included the type of crime and Study 2 included the number of alibi corroborators as additional independent variables. We hypothesized that alibis would be viewed more positively when they were disclosed earlier rather than later, were corroborated by strong physical evidence and multiple corroborators, and involved less violent offenses. As hypothesized, in both studies, alibis with strong physical evidence were thought to be more believable than those with no physical evidence but the number of corroborators and type of crime did not affect any dependent measures. Delayed timing had some negative effects on views of the defendant's character. Corroborative physical evidence affected alibi believability consistently, and contextual factors mattered less. Both implications and suggestions for future research are further discussed.

Quality vs. quantity: the effect of relationship and number of corroborators on alibi assessments

The effect of the suspect-corroborator relationship and number of corroborators on alibi assessments was examined across two experiments. In both experiments, we explored the effect of relationship type and number of corroborators on believability, likelihood of guilt, and decision to retain the suspect as the primary suspect; we increased the social distance between the alibi provider and suspect and the size of difference between the number of corroborators in Experiment 2. Collectively, our results support Olson and Wells' taxonomy of alibi believability as (a) any form of person evidence mitigates pre-alibi judgments of guilt (although there is a ceiling effect), and (b) alibis corroborated by non-motivated others were judged more favourably than those corroborated by motivated others. Our results lend support toward extending the original taxonomy to include the number of corroborators. The implications for the alibi assessments are discussed.

Children as alibi witnesses: the effect of age and confidence on mock-juror decision making

This study investigated the influence of child alibi witness age and confidence upon mock juror decision making. Participants (N = 145) read a mock murder trial transcript containing the evidence of a defendant and a corroborating child alibi witness. Six versions of the trial transcript were created manipulating the alibi witness's age (8, 12, 16 years of age) and the confidence they displayed (high, low) while giving evidence. Despite a tendency towards returning not-guilty verdicts, no associations between alibi witness age, confidence and verdicts were found. However, confident alibi witnesses were perceived as more honest, accurate and reliable than unconfident alibi witnesses. The findings do not support the two-factor model of witness credibility, but do suggest that the alibi scepticism commonly found towards adult alibi witnesses may not extend as strongly towards children corroborating the defendant's alibi. More research is required before policy recommendations can be made.

True and false alibis among prisoners and their detection by police detectives

The present study was designed to determine whether differences exist between true and false alibis and how accurate police detectives and lay people are in determining the veracity of alibis. This article provides a replication of the research by Culhane et al. (2013) with more representative participants. In the first experiment, real suspects in a remand prison generated true or false alibis. In the second experiment, a subset of those alibis were written out and were provided to experienced police officers and students for alibi evaluation and discrimination. Our results show that differentiating between true and false alibis is difficult, and even when more representative materials and participants are included, the accuracy did not exceed 60%. Interestingly we found that students and police officers focus on other aspects during the alibi discrimination. Thus, research using student participant cannot be, directly, used in alibi discrimination studies.