If he was put on probation and did not comply with the terms the judge will either give him a jail sentence of 90 days, 6 months, or a year, or continue him on probation. If you do not go to the probation appointments you are asking to go to jail, but if he is young and does not have a bad record perhaps the judge will just give him time served or a few months and he will not have probation after he serves the sentence. People will often not appear since they know they will test positive for drugs or because they abscond.
Answered on Nov 06th, 2012 at 9:15 PM