Weapon focus
（重定向自Weapon effect）
Weapon focus is a factor affecting the reliability of eyewitness testimony. Weapon focus signifies a witness to a crime diverting his or her attention to the weapon the perpetrator is holding, thus leaving less attention for other details in the scene and leading to memory impairments later for those other details. Elizabeth Loftus, Yuille and Burns, have all been associated with studies showing the existence of a weapon focus effect. According to a 2001 survey of eyewitness experts, 87% found the effect sufficiently reliable to form the basis of expert testimony in criminal trials.