John Mancos, a Pennsylvania State Constable, was stabbed to death by Michael Plavetich while attempting to serve a warrant on his wife, Cecelia, in Braddock Park on July 22, 1925. The warrant alleged assault and battery against a neighbor.
Plavetich, who claimed the police were treating his wife with excessive force, pled guilty to voluntary manslaughter and was sentenced to two to four years in prison.
State Killings in the Steel City: The History of the Death Penalty in Pittsburgh 