Since 1997, there’s been an easy pipeline of combat equipment from the military to local community police departmentsincluding assault rifles, grenade launchers, and bomb-detonating robots. In 2014, that police departments in Arizona had collectively amassed a military arsenal that included: 712 rifles, 64 armored vehicles, 42 forced-entry tools, 32 bomb suits, 704 night-vision items, 830 units of surveillance equipment, and, in at least one department, a .50 caliber machine gun that shoots bullets powerful enough to blast through the buildings on multiple city blocks.