Is it true that criminality drops rather abruptly after a person's 25th birthday?

Not really since it refers to career crimes rather than general illegal acts. It's said that with age career criminals settle for having families and friends, mainly of the opposite sex and not repeated prison sentences which yield a prison live instead. However, this idea doesn't cover the 30 year old who decides to shot some one. And with drugs, it is not much truth since, there is usually too much money involved to retire at 25. I think it's a study of burglaries and robbery types.