The video of George Floyd's death was critical evidence in the murder trial of convicted ex-Minneapolis police officer Derek Chauvin. That video and others are changing trials and police training.
Overhauling police has been a critical issue for more than two years after the release of a video which showed a white Chicago police officer shooting and killing a black teenager.
Small police departments struggling with high crime and low budgets tend to pay fast-food wages, may employ officers with troubled pasts and can miss out on opportunities to learn from mistakes.
Author Andrea Ritchie wants the incidents of police violence involving women of color and transgender women to get as much attention as black men and boys have received in recent years.
Law enforcement officers are using the trucks to prevent vehicle attacks like the one in Charlottesville that killed one woman and injured several other people.