Paul Shanley, a former priest convicted in 2005 of raping a child, is set to be released from prison.

Shanley was sentenced to spend 12 to 15 years behind bars. The Middlesex District Attorney's office said in a statement that it hired two doctors determine whether he could legally be detained longer as a "sexually dangerous person." Both experts "concluded that Shanley does not satisfy the legal criteria for a petition to be filed," the release also stated. 

Mitchell Garabedian, a Boston attorney who helped bring the Catholic Church's sex abuse scandal to light, disagreed with that assessment.

"I'm concerned that [Shanley] will sexually abuse innocent children once he gets out of prison," Garabedian told WGBH News. "Most predators abuse as many children as they can get their hands on. Predators don't stop because they get old."

Garabedian has represented dozens of people who alleged that Shanley molested them. (At one point, the priest stood accused of abusing 26 boys.) He says his clients believe Shanley's release is a defeat for them and a triumph for those who hid the abuse to shield the church from legal scrutiny.

"Some of my clients feel as though Father Paul Shanley won, that the supervisors of  Father Paul Shanley won, that Bernard Cardinal Law won, and they were allowed to get away with the wholesale rape and sexual molestation of children," he added.

Once released, Shanley will remain on probation for 10 years. He is also not allowed to have any contact with children under the age of 16.

Shanley became a central figure in the world-wide sexual abuse scandal that engulfed the Roman Catholic Church, emerging as the symbol of the abusive priest repeatedly transferred from parish to parish to avoid scandal. 

Shanley is now 86 years old.

Reporter Mark Herz contributed reporting to this story.

An earlier version of this story stated Bernard Cardinal Law's name as Bernard Cardinal.