Using 2014’s street protests in Ferguson, Mo., as a framing device, Craig Atkinson’s documentary looks at the growing militarization of America’s police force. He checks in with small towns that are snapping up surplus military equipment, including massive armored personnel carriers and high-tech body armor. (The glut of this war-ready material is a byproduct of our ramp-down in Iraq and Afghanistan.) But it’s not just equipment: Atkinson’s film suggests that certain training programs create an us-against-them mentality that further emphasizes the “war” mentality of policing. One for-hire trainer explains to a room full of law-enforcement personnel that “[superior] violence is your tool.” But not always, as we see in a disturbing raid on one man’s house, where the extreme amount of force hardly matches the crime in question.