All crime in USA is decreasing and we know the answer why:
1) Abortions and Birth Control
2) More (and aggressive) prosecutions (zero tolerance) and incarceration.
3) More (and aggressive) policing and record keeping.
4) Extensive expansion of the use of cheap strong pot.
5) Cheap high-caloric foods with sugar and msg (sedatives), and obesity.
6) Cheap video games, and other entertainment.
7) Free, and endless pornography – vastly underrated social benefit.
8) Reduction of leads in gas, paint, and other products.
9) Dramatic drop in testosterone levels due to suppression of dominance exercise, fitness, (and possibly estrogens in plastics).
Also, crime is almost entirely concentrated in certain demographic distributions, and outside of those distributions our crime is about that of europe, with less petty crime here, and more petty crime there, and more white collar crime here and less there.