New research reveals crime involving adolescent offenders is declining. Trends show a dramatic decrease in teens committing the worst violent crimes over the last 10-15 years. And despite media reports focused on younger teens, the average age of the juvenile delinquent has steadily increased over the past three decades. Violent offenses committed by teens are more likely to be misdemeanors rather than felonies, according to a study done by the Center on Juvenile and Criminal Justice: Teenage Criminals Getting Younger and Younger? Exposing Another Urban Legend.