Since the 19th century the justice system for juveniles has been constantly evolving. There's no clear-cut answer, but research and expert testimony suggests early intervention is a crucial element.
In San Francisco in 1936 a series of holdups escalated into armed robbery and eventually murder, all carried out by a trio of teens that the newspapers dubbed the "Baby Bandits".
At 16 years old Sarah Johnson murdered both her parents in a shocking case of parricide in Idaho in 2003. Although she has always protested her innocence, she remains behind bars with no chance of release on the horizon.