The New York Times ran a piece back in June about the rapid militarization of America's police departments through the Congress-backed military-transfer program, which began in the 90s, and has ballooned since 2006. Above is a graphic showing the raw numbers for select military items that have found their way to police departments, and the distribution of Mine-Resistant, Ambush Protected (MRAP) vehicles.
Read the full story at the Times. It's a good look at how some departments rationalize their way into equipment that they know they don't quite need:
A quiet city of about 25,000 people, Neenah has a violent crime rate that is far below the national average. Neenah has not had a homicide in more than five years. ...
Neenah's police chief, Kevin E. Wilkinson, said he understood the concern. At first, he thought the anti-mine truck was too big. But the department's old armored car could not withstand high-powered gunfire, he said.