Rayshard Brooks was arrested for being drunk/on drugs/whatever and behind the wheel. For all the cops knew he could have driven there under the influence or got under the influence in the car at the Wendy's then drove away sometime later putting everyone else in danger. He was all jovial to the cops until he realized that the cops weren't letting him go with a warning. Then he body slammed one cop and tried to use the other's taser almost killing the cop.