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. No date has yet been set for a retrial, which must take place within 120 days.

A prosecutor told jurors in her opening statement Tuesday that DNA on the murder weapon matched that of the defendant, the Tribune-Review reported. Defense attorney Carmen Robinson, however, said the case was about “a rush to judgment and a biased investigation.” Prosecutors last month notified the court that they no longer intended to seek the death penalty if the defendant is convicted of first-degree murder.