A protester throws a rock and Minneapolis police respond with a flash-bang grenade as violence erupts at the third precinct police headquarters two days after George Floyd died while in police custody, in Minneapolis, Minnesota, May 27, 2020. A bystander posted a video on social media that appeared to show the 46-year-old Floyd pleading with police that he couldn't breathe as an officer knelt on his neck on 25 May 2020.