More than any other parole-eligible prisoners, sex offenders in Colorado must prove that they can function in society before they are released.

They can prove themselves by undergoing treatment therapy classes and by passing lie-detector tests, all mandatory under the Lifetime Supervision Act, a 1998 law that sentences sex offenders.

For some sex offenders — including former Colorado Springs police officer Joshua Carrier, who was recently convicted of 144 sex assault counts — release into the community might never be an option. The Lifetime Supervision Act, which was designed to shuttle offenders out of prison, is what will keep Carrier in, probably for the remainder of his life.

The Lifetime Supervision Act mandates that some offenders, such as Carrier, receive indeterminate sentences — a sentence without a release date and one that can be prolonged if the prison system decides the offender is not ready to re-enter the community. It can become a lifetime sentence — one of treatment and supervision programs.

Carrier received a minimum sentence of 70 years to life in prison.

“The reason the lifetime sentencing came in is there is an acknowledgement in Colorado that there is no known cure for Colorado sex offenders,” said Amy Fitch, senior deputy district attorney for El Paso County. “No known cure means that some of them can learn, if they choose, if they apply themselves. For those who will not, we will keep them.”

While some offenders might make it through treatment and back into the community, Carrier, who was convicted of molesting several children at a local middle school, might never be paroled, Fitch said.

“Essentially, we determined that the safety of the community is more important than someone being free,” Fitch said.