I live in "Lost Angeles" and former police chief Bill Bratton took credit for any statistic he could. It's my belief that the reason for crime reduction here in L.A. is that the standard of living has gone up via social services and drugs as a income vehicle are more ubiquitous. (See the first 60-seconds of the intro to the film "Layer Cake" where the bank robbers realize they "are in the wrong game..." http://youtu.be/QHKI8zMHCjE )

Then there is credit card fraud too which is non-violent. In other words info and contraband crimes.