It's common knowledge that persons under the age of 18 (and sometimes 17) are considered to be juveniles in the eyes of the law.
But it's equally known that sometimes juvenile offenders are tried in adult court and receive adult punishment.
So what's the difference between juvenile and adult crimes? And when are juveniles tried as adults?
A transfer of a juvenile to adult court is called a "juvenile waiver," and it may be accomplished in three different ways:
Almost every state and the federal government permit judicial waiver, which allows a judge to exercise his discretion in trying juvenile offenders as adults.
Ordinarily, juveniles tried as adults via judicial waiver must be at least 17-years-old, and a judge must find that the offense is particularly serious or that the defendant has a long criminal record.
Some states also deny juvenile offenders the protections of juvenile court by statute. Ordinarily, these statutes require egregious offenses, like first-degree murder or rape, to be tried in adult court.
And thirdly, some jurisdictions allow prosecutors to decide whether or not to try juvenile offenders as adults. Again, the child must be of a certain age and usually must have committed a specific (usually serious) offense.
What you can take away from this is that juveniles tried as adults usually have an elevated age, have committed serious crimes, and may have already built up a long criminal history in their short lives.
In other words, they're juvenile offenders who are committing crimes most often associated with adults.