A Pennsylvania state trooper has sued Pittsburgh police, saying they arrested him on false charges and used excessive force when he tried to calm down a rowdy groomsman following a brawl after his brother's wedding.

Thirty-five-year-old Trooper David Williams of Plum filed the lawsuit Tuesday in federal court in Pittsburgh. He claims city officers falsely claimed he attacked and confronted them when, in fact, they pushed and punched him for no reason, escalating a situation he was trying to help them control.

City police policy is to not comment on litigation. The city's law department didn't immediately comment.

But Williams' attorney, Timothy O'Brien, says the case is important because if a fellow officer can be abused, "who amongst us is not in danger of having it happen to them?"