From Law Enforcement Today:

Police said that they received a 911 call after the shooting from a man claiming they shot someone at the protest who had approached their vehicle and pointed a rifle at them.
Police brought the caller and another individual–who claimed they fired back at the vehicle as it drove away–in for questioning. That person has not yet been identified.
Police confiscated both of the involved person’s handguns, but both individuals have been released. Both had concealed handgun licenses, said police in a press conference on Sunday.