A man convicted of murder as a suspected member of the notorious 'Ripper Crew' that killed as many as 20 Chicago-area women in the 1980s has been released from prison, according to a statewide alert sent Friday morning.

Thomas Kokoraleis, now 58, was part of a widely publicized crime story in the 1980s as one of four men accused of being part of a satanic cult that abducted, tortured, mutilated and killed women. He was initially sentenced to life in prison in 1984.

But a plea deal was struck during an appeal that allowed for his release this week. The option for such an early release infuriated victims' families.

This undated photo provided by the Illinois Department of Corrections shows Thomas Kokoraleis who was originally sentenced to life for the murder of 21-year-old Lorraine 'Lorry' Ann Borowski

An alert from Illinois' victim notification system was issued at 6:22 a.m. Friday noting Kokoraleis had been released.

His whereabouts weren't immediately known but he has three days to register at a new address, and his address will become public record as part of Illinois' sex offender registry, state officials told the Chicago Tribune.

Records show he was held at the medium security Illinois River Correctional Center in Canton, about 30 miles west of Peoria in central Illinois.

Lorraine Borowski (pictured) was brutally mutilated and raped before she was killed. Kokoraleis pleaded guilty to her murder in exchange for serving half of his 70-year prison term

Linda Sutton, a 26-year-old mother of two, was raped and stabbed to death

Shui Mak, 30, was beaten to death. She disappeared in Hanover Park in May 1982

Sandra Delaware, 18, was raped, stabbed and strangled in Chicago

Rose Beck Davis, 30 was raped, beaten with an ax and stabbed to death

Video courtesy WGN

Kokoraleis was convicted in the 1982 slaying of 21-year-old Lorraine 'Lorry' Ann Borowski.

A judge sentenced him to life in prison, rejecting prosecutors' request for the death penalty. But a state appeals court reversed the conviction in 1986, citing legal errors.

The court ordered a new trial, but Kokoraleis instead pleaded guilty in exchange for serving half of his 70-year prison term.

Jason Sweat, spokesman for the Illinois Prisoner Review Board, said the state was legally required to release Kokoraleis because he had served the maximum possible amount of time on that sentence.

Lorry Borowski's brother Mark, from left, attorney Gloria Allred, Borowski's mother Lorraine and family friend Liz Suriano talk at a news conference on September 6, 2017, opposing the release of Kokoraleis from prison

Illinois Department of Corrections spokeswoman Lindsey Hess said Friday that he had completed his maximum sentence required by law and is no longer under the agency's supervision.

Kokoraleis won't have to follow typical parole conditions because he completed the mandatory supervised release period while in prison.

Attorney Gloria Allred said in a news release that victim relatives planned a Friday afternoon news conference at a suburban Chicago hotel to speak about Kokoraleis' release.

Kokoraleis younger brother Andrew was killed by lethal injection 20 years ago at age 35 before Illinois eliminated the death penalty

Kokoraleis is likely the only member of the four-man gang with a chance to rejoin society.

His younger brother, Andrew, was executed by lethal injection 20 years ago at age 35, before Illinois eliminated the death penalty.

The other two men, Edward Spreitzer and Robin Gecht, have used all of their eligible appeals, though Gecht will be eligible for parole if he lives to be 89.