In Re Gault (1967)
Because 15-year-old Gerald Francis Gault had previously been put on probation, an Arizona Juvenile Court judge had no hesitation in committing him to State Industrial School until the age of 21 when he was accused of making an obscene phone call.  The US Supreme Court decided to take the case in order to review the adequacy of Arizona 's delinquency proceedings.  It decided that the juvenile court was basically a "kangaroo court" and that juveniles should have all the due process protections of adults in criminal proceedings.

http://supreme.justia.com/us/387/1/case.html