ST. LOUIS (AP) — A St. Louis police officer is suing the city and the police department, claiming he was violently beaten by colleagues while working undercover during a protest.

The St. Louis Post-Dispatch reported Tuesday that Luther Hall’s lawsuit mirrors allegations made by federal prosecutors in the November indictment of four police officers. One officer pleaded guilty earlier this month to lying to the FBI. The other three have pleaded not guilty.

Hall was working undercover on Sept. 17, 2017, during a protest that followed the acquittal of former officer Jason Stockley, who is white, in the fatal shooting of a black suspect.

The lawsuit says the other officers named in the suit did not know Hall was a colleague. The suit says he was slammed to the ground, kicked and beaten.