This is a story about the gun that killed Sgt. Patrick McDonald last year after a car stop, street chase and shoot-out, and how it came to Philadelphia. The weapon - a Taurus, Model PR 145 Pro, a .45-caliber semiautomatic pistol - was found clutched in the hand of Daniel Giddings, 27, released from state prison 33 days before the Sept. 23, 2008, murder. McDonald, 30, a highway cop with eight years' experience, stopped Giddings' car, and the ex-con took off. He turned... (GunPolicy.org)