State leaders also want to know if parole officers missed an opportunity to put Rafael Jones, Officer Moses Walker's accused killer, in jail three days before the murder.
The family of slain Philadelphia Police Officer Moses Walker filed a federal lawsuit that contends the state parole board is to blame for his death.
The wrongful death and civil rights lawsuit filed Tuesday argues that Walker's alleged killer should have been behind bars.
Investigators said Rafael Jones, 23, was released from prison 10 days before he and another man, Chancier McFarland, allegedly shot and killed Walker on Aug. 18 during a robbery as the officer walked home in street clothes after his shift.
The lawsuit said Jones was supposed to be under electronic monitoring and failed a probation office drug test but wasn't taken into custody as a judge had ordered.
Also named in the lawsuit are parole board chairman Michael Potteiger and a parole officer, among others.