The Iowa Court of Appeals has overturned the murder conviction of a Des Moines man who played a role in a fatal 2013 beating at a party along the Des Moines River near Wells Fargo Arena.

Kent Anthony Tyler III, 20, was convicted of second-degree murder in the Aug. 24, 2013, death of Richard Daughenbaugh, 40. Witnesses at a December 2013 trial testified that Tyler punched Daughenbaugh once after Daughenbaugh drove his pickup truck into a parking lot where dozens of young people were throwing a late-night party.

Witnesses said Tyler knocked Daughenbaugh to the ground after he grabbed Tyler’s arm. After the punch, a group attacked and “stomped” Daughenbaugh, leaving him with fatal injuries. But there was no evidence that Tyler participated in the attack after his punch.

At sentencing hearing, Tyler told a judge he shouldn’t be sent to prison for the beating. He received a 50-year sentence that he’s serving at the Anamosa State Penitentiary.

“I was protecting myself. … I am not responsible for other people’s actions,” Tyler said.