Protesters are vowing to demonstrate outside the Massachusetts prison where a notorious figure in the Boston clergy sex abuse scandal is being released after completing a 12-year sentence for raping a boy in the 1980s.

Paul Shanley is expected to be released from the Old Colony Correctional Center in Bridgewater on Friday.

Shanley was a "street priest" who ministered to alienated youth in the 1960s and '70s. Decades later, dozens of men came forward and said Shanley had molested or raped them. He was defrocked by the Vatican and convicted of raping a boy at a Newton parish.

Sexual abuse victims say they're concerned the 86-year-old Shanley will not have enough supervision after he's released. He'll be monitored by probation officials, but isn't required to wear an electronic monitoring device.