One of the most vocal bystanders as a Minneapolis police officer murdered George Floyd three years ago is suing the city, alleging he was assaulted and suffered emotional distress as he witnessed the handcuffed Black man beg for his life, go limp and stop breathing.

Donald Williams of Minneapolis filed the lawsuit Tuesday in Hennepin County District Court.

While now ex-officer Derek Chauvin kneeled on Floyd’s neck on May 25, 2020, he threatened Williams and other bystanders with a can of mace, shaking it at them after Williams expressed concern for Floyd, according to the lawsuit.

The lawsuit also alleges that Chauvin and another now-former officer, Tou Thao, taunted Floyd, Williams and other bystanders who expressed concern and that Thao placed his hand on Williams’ chest. Williams took those actions as threats and, the lawsuit says, he was fearful for his safety and the safety of the other witnesses.

The lawsuit says Williams is seeking more than $50,000 for each count, a standard dollar amount that must be listed in Minnesota if a plaintiff intends to seek anything above that figure. He alleges one count of assault, one count of intentional infliction of emotional distress and one count of negligent infliction of emotional distress.

Because of the officers’ conduct, William has endured emotional distress, pain, suffering, humiliation, embarrassment and medical expenses, according to the lawsuit.

A city spokesperson told The Associated Press in an email Wednesday that the City Attorney’s Office does not have a comment.

Chauvin was convicted of state murder and manslaughter charges in Floyd’s death and was sentenced to 22 1/2 years in prison. Chauvin also pleaded guilty to a separate federal charge of violating Floyd’s civil rights and was sentenced to 21 years on that count. He is serving the sentences concurrently at a federal prison in Arizona.

Thao was recently convicted of aiding and abetting manslaughter and is awaiting sentencing on that count. He has also been convicted of violating Floyd’s civil rights and received a 3 1/2-year federal sentence.

Floyd, a Black man, died May 25, 2020, after Chauvin, who is white, pinned him to the ground with his knee on Floyd’s neck for 9 1/2 minutes as he pleaded for air. The killing, captured on bystander video, touched off protests around the world and prompted a national reckoning with police brutality and racism.

Williams, a former wrestler and a mixed martial arts fighter who also worked security, testified during Chauvin’s trial. He said Chauvin appeared to increase the pressure on Floyd’s neck with a shimmying motion and in response he had yelled at Chauvin that he was cutting off Floyd’s blood supply.

Williams was asked during the trial if he grew angrier as the arrest continued, and he agreed that he did. He also didn’t disagree when a lawyer for Chauvin said Williams also called Chauvin names multiple times including “tough guy” and a “bum.”

Thao stepped toward Williams and touched him as a result of Williams’ expressing concern for Floyd’s safety, the lawsuit says. Thao was facing the bystanders and admonishing them to stay on the sidewalk, and then moved toward Williams when he appeared to step off a curb, according to trial testimony.