[J]uvenile sexual assault victims know their perpetrator a staggering 93 percent of the time. Often, it's a family member. Frequently, it's another child. Rarely is it a stranger.
Also notable: "In studies... it has been established that about six percent of the boys of a given age will commit half or more of all the serious crime produced by all boys of that age[.]" Crime, James Q. Wilson (1995).