Philadelphia's top prosecutor will fight a decision that gives former Black Panther Mumia Abu-Jamal a new appeals hearing in a 1981 police slaying.

District Attorney Larry Krasner said in a filing Friday that he'll challenge an order that would revive the high-profile case. The 64-year-old activist is serving life without parole after his death sentence was thrown out over flawed jury instructions.

He has now been granted a new appeals hearing because of a Supreme Court ruling that said a former Pennsylvania justice who heard his appeal had a potential conflict of interest.

Krasner has tangled with the city's police union since taking office last year, especially over pleas that spared two men the death penalty in a 2015 police slaying.