RALEIGH, N.C. – North Carolina officials on Thursday said they were rescinding decades of good behavior credits that had been awarded to dozens of violent inmates – prisoners who thought they were going to be freed because of a quirky 1970s law that limited a life sentence to 80 years.

Gov. Beverly Perdue said the inmates will not be allowed to accrue the credits to shorten their time behind bars. Those credits will only be used to improve an inmate’s chance at parole.

“I will continue to pursue all legal means of preventing the release of these inmates without any review by the parole board or any post-release supervision,” Perdue said in a statement.

Inmate Bobby Bowden had successfully argued in state courts that his life sentence was defined as 80 years – something Perdue conceded in her statement Thursday. He had also argued that credits for good conduct knocked more than half the time off his sentence, meaning he is eligible for unconditional release.

Some of the inmates, most convicted of rape or murder, were set to be released last month. Perdue later blocked the release by arguing that officials had improperly applied some of the credits.

The potential releases appalled victims and their advocates, partially because most of the inmates would be freed without any post-release supervision. Only one would have had official supervision, although those convicted of rape would have to register as sex offenders.

A handful of those inmates have been working toward time outside of prison, using volunteer or work-release programs to spend time in society. They can eventually be approved for supervised release by the parole board.