actually, the amount of children killed by parents pales in comparison to youth on youth violence.
Annually, about 600 children are killed in the U.S., most of them by parents.
Bureau of Justice Statistics Homicide trends in the U.S.: Infanticide
In comparison, juvenile offenders (those under 18), are responsible for literally thousands of violent crimes:
These are 2007 statistics:
Murder: 796
Robbery: 20,963
Aggravated Assault: 37,173
Arson: 5,037
Total Violent Crime: 61,343
Now, UCR only reports on arrested person data which means that the overall rate of victimization by juveniles towards juveniles and others is not known.
However, the national crime victimization survey (BJA, 2005), noted from self-report data that juveniles are victimized at a rate of 2.5 times that of adults and that MOST of those crimes are committed by OTHER JUVENILES.
Juveniles make up a disproportionately small percentage of the population considering their rate of violent offending.
However, in all fairness, the most criminally involved group is 18-24 year olds, and juvenile crime rates have dropped substantially from their highs in the early to mid 1990s. I would say that gangs played a huge role in those high levels of violence.