Mumia Abu-jamal murdered officer Faulkner...period.
There is no dispute.
Witnesses saw him shoot Faulkner.
Mumia was shot by Faulkner.
Faulkner was killed by a gun owned by Mumia, incidentally, said gun was found on Mumia at the scene.
At the hospital after the shooting, Mumia admitted to killing Faulkner.
To this day, Mumia has never offered a contradictory explanation.
On his website, the explanation now seems to be “he (Faulkner) brought it on himself”.