When police confronted Tamerlan Tsarnaev four nights after the Boston Marathon bombing last year, he leaped from his car with a 9-millimeter semiautomatic pistol and opened fire. He critically wounded one officer and, despite being shot himself, kept firing until the gun emptied or jammed. In a final act of defiance, he threw the pistol at police before he was killed. The tale of that handgun, a black Ruger P95, Serial Number 317-87693, offers new insights into the... (GunPolicy.org)