Actually, it's a little bit more complex than that, but you're basically right. Sociologists actually look at the crime rates for men vs women as an indicator of social equality. I believe that the crime rates for women are going up while they're going down for men. So it's difficult to correlate crime with sex.

That said, age does play a significant role in crime rates. Our population is aging, and that's probably the primary cause of the decreasing crime rate.