DENVER -- The state Supreme Court issued a ruling on Monday morning in favor of a convicted sex offender who argued that he was wrongly sentenced to a term of mandatory parole that was longer than his prison sentence.

The 4-3 ruling could force state authorities to release more than 1,500 sex offenders from prison or parole.

The ruling immediately affects 128 inmates convicted of sex crimes. Another 1,142 who are behind bars may not have to be on parole when their sentences are over. And 249 offenders now being tracked by corrections officials could be released from parole.

"With this ruling, there are inmates or offenders who now potentially will be released without community supervision. It's a public safety concern," Alison Morgan, department of corrections spokeswoman, said.

At issue are different interpretations of laws passed in 1993 and 1996 that modified parole terms for sex offenders.

State Attorney General Ken Salazar, who argued in court briefs that the Colorado Legislature clearly intended to increase terms of incarceration and parole for sex offenders, did not think that the ruling was a source of concern.

"I don't think that the public safety of Colorado citizens will be compromised by this decision," Salazar said.

Defense attorneys argued that the letter of the laws approved in those years requires that their clients and others be released.

"It is for the legislature, not the courts, to decide what laws best serve the public interest, and the various laws at issue here indicate some of the differing and evolving views on parole. Whether parole for sex offenders should be mandatory or discretionary is a legislative decision that we do not second guess," the Supreme Court said in its Monday ruling.

"Many sex offenders receive lengthy sentences and discretionary parole allows the parole board to keep a sex offender incarcerated for the duration of the entire sentence. On the other hand, a sex offender who receives a relatively short sentence, as is illustrated here, may serve little or no time on parole under a grant of discretionary parole," the court said.

The court case involved Vance Martin, who pleaded guilty in January 1994 to sexual assault on a child by a person in a position of trust. He was sentenced to a six-year suspended prison term and five years on probation. After a violation of his probation, Martin was sentenced in 1997 to four years in prison and five years of mandatory parole.

Martin's lawyers argued that his parole term was illegal because it exceeded his four-year prison term, but the Court of Appeals ruled in 1999 that the five-year mandatory term was legal.

Following the Supreme Court's ruling overturning that decision, nine of 112 sex offenders in custody for parole violations were released before Salazar halted any further releases. Eighty-four were released from parole.

Justices said that Martin's parole term wrongly exceeded the limits established under state law.

They said that the Parole Board has sole authority to grant or deny parole and set the length of parole terms.

"But in no event shall the term of parole granted exceed the unserved remainder of the maximum sentence imposed by the court or five years, whichever is less," the justices wrote.

The case now heads back to the state Court of Appeals with directions to send it back to the trial judge.

Prison officials said that sex offenders are prone to recommitting their crimes, and that when supervision is gone, that's when problems occur. The department of corrections is now waiting to be told who gets released, and when.

"It's a disappointment, but there's not a lot we can do at this point," Morgan said.

Officials said that a new law that makes it a felony to fail to register as a sex offender could help keep offenders in check.

7NEWS reported that the ruling could free 34 Colorado sex offenders who are now in prison on parole violations, as early as this week.

Additional Resources:

• Colorado Supreme Court Home Page
• Justices of the Supreme Court
• Colorado Department of Corrections Home Page