The weapon focus effect is weaker with Black versus White male perpetrators.

We compared the influence of a weapon's presence on eyewitnesses' memory for a White versus a Black male perpetrator. Prior data indicate that unusual objects in visual scenes attract attention and that a weapon's effect depends on how unusual it seems within the context in which it appears. Therefore, given the stereotype linking Black men and weapons, we predicted a weaker weapon focus effect with the Black perpetrator.

Judging veracity impairs eyewitnesses' memory of a perpetrator.

Witnesses to crimes sometimes perform cognitively demanding tasks while simultaneously observing a perpetrator. This division of attentional resources can cause witnesses to remember the perpetrator less accurately. We hypothesised that judging the veracity of a target individual can impair subsequent memory for his or her appearance and message.

A perpetrator's accent impairs witnesses' memory for physical appearance.

Sometimes witnesses to crimes must remember both a perpetrator's appearance and voice. Drawing upon multiple resource theory as well as previous findings that processing foreign-accented speech is more demanding than processing unaccented speech, we hypothesized that a perpetrator's accent can impair memory for his or her appearance. In Experiment 1, we used a secondary visual search task to demonstrate that processing an accented versus unaccented message demands more cognitive resources.

The weapon focus effect on memory for female versus male perpetrators.

Previous research suggests that weapons are often inconsistent with the schema activated by eyewitnesses, which leads them to attend to weapons more than they would to neutral objects. Therefore an especially strong weapon focus effect should occur when a perpetrator holds an object primarily associated with the opposite rather than the same gender. As predicted, a handgun reduced the accuracy of witnesses' descriptions of a female perpetrator more than descriptions of a male perpetrator (Experiment 1).

When a lie becomes the truth: the effects of self-generated misinformation on eyewitness memory.

This research investigated whether generating misinformation impairs memory for actual information. After watching a videotaped robbery, some witnesses were interviewed about it, but others did not rehearse the event details. One week later, the witnesses tried to remember the robber's appearance.