A cadre of murderers and rapists, several of whom victimized young girls, will be set free from North Carolina prisons this month after state courts agreed that a decades-old law defined life sentences as only 80 years long.

Dozens more inmates could be released in the coming months unless the state can figure out a legal recourse to keep them behind bars, officials said Thursday. Gov. Beverly Perdue called them "dangerous criminals" who have repeatedly been denied parole.

"I'm appalled that the state of North Carolina is being forced to release prisoners who have committed the most heinous of crimes, without any review of their cases," Perdue said in a statement.

One of the 20 inmates set for release, Bobby Bowden, had argued that a law adopted in 1974 clearly defined life sentences as just 80 years. The 60-year-old convicted murderer believed that the statute, combined with good conduct credits, means his life sentence is now complete.

The Court of Appeals sided with Bowden last year. North Carolina's Supreme Court rejected an appeal from the state earlier this month after a lawyer from the attorney general's office had argued that the 80-year figure was ambiguous and likely meant to determine when somebody would be eligible for parole.

Justices on the high court balked at that argument, and an attorney for Bowden called it "legal gymnastics." The statute, which was in place for several years in the 1970s, says: "A sentence of life imprisonment shall be considered as a sentence of imprisonment for a term of 80 years in the state's prison."

A governor's list of prisoners set for freedom describes a range of gruesome crimes: John Montgomery, 58, was sent to prison in 1973 for raping a 15-year old girl while on escape from Guilford Correctional Center. Faye Brown, 56, was convicted on a first-degree murder charge for the 1975 killing of a state trooper during a bank robbery. Steven Wilson, 52, went to prison in 1978 for abducting and raping a 9-year-old girl.

All but one of the inmates have been convicted of murder or rape. The 20th, 57-year-old Charles Lynch, was convicted of two counts of second-degree burglary and assault with intent to commit rape.

Thomas Bennett, executive director of the North Carolina Victim Assistance Network, said the plan to release the prisoners is dangerous.

"This is terrible. This is a disaster," he said. "This is another example of victims not receiving consideration in the way the system works."

The governor's office believes the state is forced to release the inmates on the 29th because of a standard response time of 20 days following a Supreme Court decision. Correction officials are in the process of notifying victims and local district attorneys about the development.

Edgecombe County Sheriff James Knight, president of the North Carolina Sheriffs' Association, said communities will need to be careful.

"The law enforcement in the jurisdictions where they're being put back out need to have a watchful eye out," he said. "We hope (the inmates) are reformed, but we have to be on the lookout. You just don't know."

Bowden was convicted in 1975 of two Cumberland County killings and initially sentenced to death. The Supreme Court later took him off death row, sending the case back for Bowden to get concurrent life sentences. He has been denied parole every year since 1987.

Corrections officials have worried that the case could eventually affect some 120 inmates sentenced when the law was in place.