A controversial decision to release serial rapist Thomas R. Duvall, one of the most violent sex offenders in state history, has cast a pall of fear and anger over people across Minnesota who were his victims years ago.

A woman who was raped repeatedly by Duvall in 1987 has changed her phone number and has begun looking for a new place to live. "We are terrified," said the woman's sister, who asked to remain anonymous.

In a south suburb of the Twin Cities, a middle-aged man who says he was molested by Duvall as a boy is considering a permit to carry a concealed firearm for the first time in his life. The man, who also asked to remain anonymous, said the permit would be "a safety precaution" in case Duvall seeks out his past victims upon release.

The two are among nearly 1,000 Minnesotans who have signed an online petition in the past week opposing Duvall's release, which was approved last Monday by a special state judicial panel.

Duvall, now 62, was convicted in the 1970s and 1980s for a series of brutal rapes of teenage girls and has admitted to assaulting more than 60 victims.

The petition has been promoted on Facebook by Duvall's victims and their relatives, who feel their voices went unheard during the long and tortuous legal case that led to his approval for conditional release from the Minnesota Sex Offender Program (MSOP).

They note that a forensic psychologist appointed by the court, who reviewed more than 10,000 pages of Duvall's criminal and treatment record, concluded that he is not ready for release. The psychologist, Dr. James Alsdurf, testified last April that Duvall is still fixated on deviant sexual thoughts, many of them "dominant and controlling."

"My fear is that Duvall can go out and rape someone again before the cops catch him," said the man who was molested. "I just don't want to be one of his statistics."

On Jan. 8 a three-judge state appeals panel approved Duvall's petition for release, saying he was "capable of making an acceptable adjustment to open society" after nearly 30 years in state custody.

The panel relied heavily on members of Duvall's treatment team at the MSOP, who testified at Duvall's hearing last year and described him as a model detainee. They argued that his progress in treatment outweighed his violent history, his diagnosis as a "sexual sadist" and violent sexual fantasies described by Duvall himself in personal journals.

"[Duvall] cannot change his past offense history, but he is committed to change in the present and future," the panel wrote in its decision.

The ruling was immediately attacked by state Attorney General Lori Swanson and Human Services Commissioner Emily Piper, who have vowed to appeal by early next week.

That would put Duvall's release on hold, with a final decision taking up to six months.

In the meantime, Duvall's victims remain on edge.

On the day after Christmas in 1987, Duvall talked his way into a Brooklyn Park apartment, bound a 17-year-old girl with an electric cord and then repeatedly raped her over a three-hour period while hitting her with a hammer.

The victim is now in her 40s, and her sister says post-traumatic stress has "nearly destroyed my sister's life." Even now, 30 years later, the woman can't hold a steady job and refuses to give her phone number to even her closest relatives, her sister said.

"We just never thought that they would actually let this guy out," the sister said. "And now we're terrified that he will do this again."

One of Duvall's early victims said he was molested at age 7 or 8 while playing hide-and-seek near his childhood home in Blaine. Duvall, he said, lured him into a dark stairwell by promising to show him a "secret hiding place," then fondled the boy's genitals while pointing a knife at his face. The man said Duvall threatened to kill him if he told any of the neighborhood children.

"After that, I didn't play outside much anymore," he said. "I shut off and hid in the basement for almost a year."

Another victim said Duvall forced him to perform oral sex on three occasions when he was 10 or 11 years old, while Duvall was in his late teens.

On one occasion, he said, he was playing with Duvall and another boy in a makeshift fort built in the rafters of a friend's garage in Blaine.

When their friend was called in for dinner, Duvall urged the boy to remain quiet and coaxed him into giving him oral sex. In a later incident, he said, Duvall pushed him out his bedroom window after hearing his mother coming down the driveway

"He had a way of talking to people, of conning them into doing what he wanted," the man said in a recent interview.

The encounters, he said, left him permanently scarred. He remained "confused about his sexuality" well into adulthood and abused alcohol and drugs to suppress the painful memories.

He is also fearful. In 2014, the man was among a group of five victims who were prepared to testify against Duvall's release at a court hearing.

At the last moment, Duvall withdrew his petition and the victims never testified. Still, the man noted that Duvall has admitted to having violent fantasies about his victims; he worries that Duvall might seek out those who were willing to testify against him.

"Duvall has caused a lot of pain in my life," he said. "There was shame. There was disgust. At some point in your life, you think it's finally over, that it's time to move forward, and then the memories come back."

To date, just 23 offenders have been conditionally discharged from the MSOP.

Most have been released in the last few years, as the state has faced increased pressure from the courts to show it is running a viable treatment program. There have been no known incidents of sex offenders reoffending after being discharged from the program.

Chris Serres • 612-673-4308

Twitter: @chrisserres