PITTSBURGH (AP) — A mistrial has been declared in the western Pennsylvania trial of a man charged in the death of an off-duty Pittsburgh police officer shot and killed in a street confrontation more than 3 1/2 years ago. Attorneys for 34-year-old defendant Christian Bey sought and were granted a mistrial ruling by an Allegheny County judge Wednesday after a prosecution witness mentioned that she had known the defendant since he moved into the neighborhood after having been “released from prison.” Bey is charged with homicide in the July 2019 shooting that killed 36-year-old Officer Calvin Hall after an apparent dispute at a Homewood block party.