SALT LAKE CITY >> He was a rising young federal prosecutor assigned to a high-profile serial murder case. She was a 16-year-old witness to a double murder. They met as he prepped her to testify in Utah, and they later had sex in the 27-year-old man’s hotel room.

Three decades later, Terry Mitchell of Salt Lake City says she now recognizes it as a weekslong series of sexual assaults that had long-ranging effects on her life.

While the prosecutor who later became a federal judge in Washington, D.C., acknowledged they had an inmate relationship that he called a mistake, Richard W. Roberts denied ever sexually assaulting her in a statement from his lawyer.

Roberts, 62, retired the day she sued him in Salt Lake City.

Mitchell said Thursday that she filed a lawsuit against Roberts on Wednesday because she’s wants to make sure that nothing like it happens to another person again.

“I never wanted money,” Mitchell, 51, now a real estate broker and married mother of two, told The Associated Press. “I just want him to get off the bench. I don’t want him to do this to anybody else again.”

She said she suppressed memories of the abuse for decades, until she got an email in 2013 from Roberts after the execution of the white supremacist serial killer at the center of the 1981 case.

After the memories returned, she went to the Utah Attorney General’s Office with her story and a recorded phone call of Roberts acknowledging the relationship, though he said it only started after the trial, according to a state prosecutors’ report.

But nearly two years after they took the case, Mitchell said the investigation seemed to have stalled with no result. A civil lawsuit seeking a total of $25 million in damages seemed like her last option, she said.

State prosecutors denied letting the case languish, but they said criminal charges didn’t make sense. In 1981 in Utah, 16-year-olds could legally have sex, and prosecutors didn’t have enough evidence to allege she’d been compelled, said Spencer Austin, Utah’s chief criminal deputy attorney general.

“If this were under the law today, I would have charged him with a felony,” he said. The statute of limitations doesn’t apply because Roberts left the state.

Instead, state prosecutors decided to file complaints based on the ethical breach of sleeping with a teenage witness. They sent their findings to several congressional committees, including the House Oversight and Government Reform Committee chaired by Utah Republican Jason Chaffetz.

Chaffetz called the report alarming and promised to look into it, but the fate of that process is unclear. Roberts retired Wednesday as chief judge for the U.S. District Court for the District of Columbia, citing medical advice for an unspecified disability, according to documents obtained by The National Law Journal.

In a statement, Roberts said that he’d had a warm correspondence with Mitchell over the years, but she said there were only a few of brief communications. Roberts’ attorneys did not return a request for additional comment on Thursday.

Mitchell’s lawyer, meanwhile, questioned how Utah handled the case. Attorney Rocky Anderson said prosecutors could have gathered more evidence that she didn’t consent and also questioned the decision to provide Roberts with a copy of their findings on Feb. 24, before Mitchell herself saw it.

Austin said prosecutors did a thorough investigation, but they wanted to keep the report close to the vest to keep word from becoming public. Providing a copy of their findings to Roberts was a necessary part of the process, he said.