The letter-writer linked from the Duke Chronicle stated, "The fact is that ballistics testing linked the bullets found in the officer's body to Abu-Jamal's gun, a gun purchased and registered in Abu-Jamal's name and found at Abu-Jamal's side on the scene. The fact is that testing also identified the bullet that wounded Abu-Jamal as coming from the officer's weapon." On the other hand
Terry Bisson wrote, "Mumia says it was someone else, and several witnesses saw another shooter flee the scene. Mumia's legally registered .38 was never decisively linked to Faulkner's wounds."
Lori Allen wrote, "In addition, the relative widths of the lands and grooves on the bullet reportedly taken from Faulkner's head wound is opposite of all, but a few percent of the Charter Arms revolvers produced. Thus, the prosecution's ballistics evidence (or lack thereof) itself raises a strong likelihood that the bullet in evidence from Faulkner's head wound was not fired by Mumia's gun. The police ballistics tests were admittedly "inconclusive" because properly and competently performed ballistics would exclude Mumia's gun as the murder weapon." I don't have any special knowledge of ballistics. However, if I were to get interested in this case, I would look into whether the National Academy of Sciences had anything to say about it in their 2009 report on forensics. Allen's article also raises the question of whether the gun found at the scene was really the officer's service revolver.