Republican Senators including Tom Cotton and Josh Hawley have invoked the death of retired St. Louis Police captain David Dorn as proof of some kind of awful epidemic of anti-cop violence coming from the political left. Dorn was working as a security guard at a friend's pawn and jewelry shop when he was tragically shot and killed during a 2:30am robbery that was unrelated to protests against police brutality.
Dorn was a black man, who was deeply beloved in the community; while his death was certainly heartbreaking, it had nothing to do with any "defund the police narrative." Pawn shops and jewelry shops do unfortunately get robbed sometimes, but not because people hate the police; these stores get robbed because there are desperate people out there who saw the risk as worth it for the potentially lucrative target. In most cases, that desperation is caused by poverty, or addiction, or mental health, or some combination of these issues — the exact same issues that most of the "defund the police" crowd believe would benefit from more focused financial resources, which have otherwise been tied up in policing.
But there is no actual evidence of any increase of extreme violence from the political left (not even from "Antifa"). The bulk of political violence — both against civilians, and police officers — continues to come from the far right.