Duh, the article says he was in rehab during his prison stint:
Trantino's adjustment to life in a halfway house might not be a complete shock. An acknowledged drug abuser, he has been participating in a drug-treatment program called Nu Way at South Woods State Prison. There inmates attend self-help and therapy groups that are similar to halfway house programs.
Considering he's been in prison for 38 years, it's a bit hard to believe that he only did drugs before the prison sentence. I stand by my original statement that his 38 years in prison have NOT been "infraction free," since he obviously has been doing drugs while in jail.