The U.S. Supreme Court on Monday rejected a case against activist DeRay Mckesson, sending it back to state courts for now. The lawsuit was filed by a police officer who was injured at a protest over the 2016 police killing of Alton Sterling in Baton Rouge, Louisiana. The unnamed officer was hit with a piece of concrete or rock allegedly thrown by a protester. The officer sued Mckesson for damages because of his affiliation with Black Lives Matter, even though the identity of the alleged assailant is unknown.