Presentation order of ID and Alibi evidence was manipulated for undergraduate participants who conducted a simulated police investigation. Experiment 1 found a recency effect when an eyewitness rejected the investigator's suspect. Experiment 2 also examined order effects, exploring how participant-investigators evaluated alibi information in addition to eyewitness ID information. When investigators saw the witness identify the suspect but also received a strong alibi for that suspect a recency effect occurred, such that whichever piece of information occurred at the end of the procedure had the strongest impact on investigators. Thus, type of evidence and evidence order both had a dramatic influence on participant-investigators' decisions.

We explored the effects of presentation order and evidence strength on participants acting as investigators in a criminal context. Participants evaluated evidence and suspect guilt in a study in which alibi witness and eyewitness evidence of varying strength, presented in different orders, were compared. In contrast to research on the confirmation bias, which suggests that evidence presented early distorts subsequent evaluations of evidence, the present findings suggest that under certain circumstances, evidence received most recently can have a greater impact on decision-making. Recency effects were observed most frequently when recent evidence was particularly strong and often when it contradicted previously encountered strong evidence. The impact of recency extended beyond the impact of evidence and to evaluations of the credibility of individual pieces of evidence. Copyright

Undergraduate participants who conducted a simulated police investigation were presented with either a child (6 years old) or adult (25 years old) alibi witness, who was either the son or neighbor of the participant's suspect. Replicating previous research, participants were more likely to believe the adult neighbor alibi witness than the adult son. In fact, an alibi provided by the adult son actually proved detrimental to that suspect, as participants thought the suspect was more likely to be guilty after viewing an alibi provided by the adult son. However, child-provided alibis reduced perceptions of suspect guilt, regardless of that child's relationship to the suspect. The child alibi witnesses were also viewed by the participants as more credible than the adult witnesses.

This research examined the influence of eyewitness identification decisions on participants in the role of police investigators. Undergraduate "investigators" interviewed confederate "witnesses" and then searched a computer database of potential suspects. The database included information on each suspect's physical description, prior criminal record, alibi, and fingerprints. Participants selected a suspect and estimated the probability that the suspect was guilty. Investigators subsequently administered a photo lineup to the witness and re-estimated the suspect's guilt. If the witness identified the suspect probability estimates increased dramatically. If the witness identified an innocent lineup member or rejected the lineup, investigators' probability estimates dropped significantly, even when pre-lineup objective evidence (e.g., fingerprints) was strong. Performance of participants acting as witnesses in two baseline studies was at chance. Therefore, participant-investigators greatly overestimated the amount of information gain provided by eyewitness identifications.

We investigated the effects of post-identification feedback and viewing conditions on beliefs and interviewing tactics of participant-investigators, crime reports of participant-witnesses and participant-evaluators' credibility judgments of the witnesses. Study 1 participants assumed the roles of witness and investigator (N ¼ 167 pairs). Witnesses' view of a simulated crime video was manipulated by distance from viewing monitor: 2 or 9 ft. Participants made a line-up identification and received either positive feedback or no feedback. Significant effects for witnesses and investigators were associated with viewing condition and post-identification feedback. Interviews between investigator-witness pairs were videotaped. Investigators asked more positive, leading questions when they were led to believe that the witness had identified the suspect. In Study 2 evaluators (N ¼ 302) viewed the witness-investigator interviews. Viewing condition had no effect on judgments of witness credibility but positive post-identification feedback led evaluators to judge witnesses as more credible than witnesses who received no feedback.