A 70-year-old convicted rapist on Friday lost his bid to gain more freedom from the Minnesota Sex Offender Treatment Program in St. Peter. The program confines more than 600 dangerous sex offenders after they leave prison. A three-judge panel denied John Rydberg’s request for a provisional discharge, saying he remains a public safety threat. His convictions for rape and other sex crimes date back to the late 1960s. Rydberg wanted to move to a Twin Cities halfway house from the Sex Offender Program’s St. Peter campus. Rydberg’s case came before a judicial panel last year also as lawmakers across the country struggled to balance state budgets. It re-opened the debate about the costs and legal wisdom of civil commitment programs for sex offenders.