The United States made a disastrous miscalculation when it started automatically trying youthful offenders as adults instead of handling them through the juvenile courts. Prosecutors argued that the policy would get violent predators off the streets and deter further crime. But a new federally backed study shows that juveniles who do time as adults later commit more violent crime than those who are handled through the juvenile courts.

The study, published last month in The American Journal of Preventive Medicine, was produced by the Task Force on Community Preventive Services, an independent research group with close ties to the Centers for Disease Control and Prevention. After an exhaustive survey of the literature, the group determined that the practice of transferring children into adult courts was counterproductive, actually creating more crime than it cured.

A related and even more disturbing study by Campaign for Youth Justice in Washington finds that the majority of the more than 200,000 children a year who are treated as adults under the law come before the courts for nonviolent offenses that could be easily and more effectively dealt with at the juvenile court level.

Examples include a 17-year-old first-time offender charged with robbery after stealing another student’s gym clothes, and another 17-year-old who violated his probation by stealing a neighbor’s bicycle. Many of these young nonviolent offenders are held in adult prisons for months or even years.