Charges in the rape of a 17-year-old runaway more than 18 years ago in Minneapolis have been filed thanks to investigators reopening the case in 2010 and securing a DNA match that revealed an incarcerated serial rapist as the perpetrator.

James E. Williams, 59, of St. Paul, was charged last week in Hennepin County District Court with third-degree criminal sexual conduct in the August 1996 attack on a 17-year-old girl he had met that evening at the Dakota County fairgrounds, where both were working.

Williams, now residing at the state’s secure Moose Lake treatment center after his commitment in 2006 as a sexually dangerous person, has four other sex assault convictions on his record, three occurring in Milwaukee and another in Ramsey County.

According to the charges filed in this latest allegation:

The teen moved out of her mother’s Dakota County home and was working and camping at the fairgrounds. That’s where she was introduced to Williams, who was 41 at the time.

She got into Williams’ vehicle with another man and drove to Minneapolis to buy marijuana. Williams and the girl “ended up alone together,” however, and he pulled over and raped her before returning his victim to the fairgrounds.

The victim told a friend and the Sheriff’s Office what happened. She went to Hennepin County Medical Center, where evidence was collected for a sexual assault kit, and police interviewed her.

In March 2010, as part of a law enforcement cold case initiative, the evidence in the kit was tested for DNA. Results six months later showed a match of the semen taken from the teen to a match with Williams’ DNA on file in the convicted offender database.

In May 2014, the victim agreed to speak with officers and explained how she met Williams and was raped by him.

With the DNA match and the victim’s allegations in hand, officers visited Williams in the Moose Lake center. He denied raping the girl, saying he was incarcerated at the time. Records, however, contradicted that statement.

He also denied having worked at the fairgrounds and denied raping the girl.

Once officers “advised [Williams] of the forensic link between him and the victim,” the criminal complaint read, Williams “changed his account” and conceded that he may have been “partying” with the girl and had intercourse with her.

Officers obtained a swab of DNA from Williams and confirmed that it matched the DNA of the semen taken from the victim in 1996.

There were several reasons for why authorities did not speak with the victim for nearly four years after the DNA match in 2010, a county attorney’s office spokesman said.

Williams “already was locked up with no release date, [so] we didn’t face any deadlines to charge,” said spokesman Chuck Laszewski. “We had to locate and interview the victim, interview Williams, get a search warrant to obtain DNA material from him, then run the new DNA material and compare it to DNA from the crime.”