When police shoot and kill someone, the officers’ descriptions of what they saw and felt – and accounts of the danger facing them or someone else – can be a major part of the defense, experts say. “In many of the shooting cases, the officer will say, ‘I perceived a threat in the form of reaching for a gun, or an aggressive move towards me,’” said Rachel Harmon, a UVA law professor. “It is difficult for the state to disprove the perception of that threat.” In George Floyd’s case, Harmon said, “there’s not the same kind of ability to claim a perception of a threat.”