Some facts about "weapon focus."

TLDR

Weapon focus refers to a crime witness’s attention concentrating on a weapon, which reduces recall of other crime details. The study presented slide sequences of a fast‑food restaurant incident, with half showing a gun and half a check, and recorded eye movements to assess where witnesses looked. Subjects made more and longer fixations on the weapon and remembered the weapon scenario less well, providing the first direct empirical support for weapon focus.

Abstract

“Weapon focus” refers to the concentration of acrime witness's attention on a weapon, and the resultant reduction in ability to remember other details of the crime. We examined this phenomenon by presenting subject-witnesses with a series of slides depicting an event in a fast-food restaurant. Half of the subjects saw a customer point a gun at the cashier; the other half saw him hand the cashier a check. In Experiment 1, eye movements were recorded while subjects viewed the slides. Results showed that subjects made more eye fixations on the weapon than on the check, and fixations on the weapon were of a longer duration than fixations on the check. In Experiment 2, the memory of subjects in the weapon condition was poorer than the memory of subjects in the check condition: In Experiment 1 similar, though only marginally significant, performance effects were obtained. These results provide the first direct empirical support for weapon focus.