In a state prison system that is more than 5,000 inmates over capacity, it's common for inmates to leave at their minimum sentence. But a recent brutal stabbing by an early parolee has put the state's probation and parole system under a microscope. Defenders of the parole system say get-tough calls can backfire. In March, Gov. Ed Rendell released an 18-month study he commissioned of the parole system. The report, written by John Goldkamp, chairman of the Department of Criminal Justice in Temple's College of Liberal Arts, expressed "great concern" over laws mandating no parole, arguing they can lead to offenders going back onto the streets with no follow-up programs.