I’ve looked for stats, and if one just uses incarceration rates it’s rather low. That of course doesn’t paint an accurate picture, as many individuals both American and foreign do not receive any prison time particularly if the offense is not considered serious or it’s a first time offense.
http://heyjackass.com/
These two sites offer some data for you. The first explains that, at least in Chicago, embarrassing crime stats are stroked by simply downgrading the offences.
The second simply offers an actual running tally of the constant savagery of Baghdad By the Lake. That IEDs are not used is only because they are too effing stupid to know how to build them.