A Montana man who recently was granted clemency after spending three decades behind bars for a murder he says he did not commit is using some of his regained freedom to help reform the criminal justice system.

On Friday, Barry Beach addressed a forensic science class at the University of Montana.

The Missoulian reports that Beach told the class that the forensic evidence in the case was mishandled from the beginning. He says the students can prevent cases like his from happening again.

The 53-year-old Beach was released from the Montana State Prison three weeks ago after Gov. Steve Bullock granted his clemency request.

His release culminated three decades of fighting for his freedom after being given a 100-year sentence for the 1979 beating death of a 17-year-old girl.