SCANNING THE BACKSIDE OF THE CASING ALLOWS POLICE TO UNDERSTAND THE EXACT GUN THE BULLET CAME FROM. CONNECTING GUNS TO DIFFERENT SHOOTINGS LIKE THIS IN HERE, ALMOST IDENTICAL. SAME GUN.

Nara prefectural police believe Tetsuya Yamagami, 41, the murder suspect, used commercially available bullets with his homemade gun. The gun ... metallic barrels and plastic pieces that appear ...