Timothy Vafeades faces more than 20 years in prison after several women claim he trapped and tortured them in his semi truck. (Gillian Brockell/The Washington Post)

The woman told investigators she met Timothy Jay Vafeades at the Sapp Brothers truck stop in Salt Lake City. It was April 2012, and she got into his tractor-trailer after agreeing to get dinner with him, according to court documents.

But about 10 minutes into the drive, Vafeades told her that  “they were not going to dinner and that she was going on the road with him for a week or more,” an FBI agent wrote in a criminal affidavit. “She reported that she knew she could not do anything.”

For months after that, investigators allege, Vafeades forced the woman to live with him, work on the truck — and have sex with him almost daily.

Vafeades told the woman “she was his ‘slave’ on the truck,” and he beat her often, according to the affidavit.

Vafeades was eventually charged with kidnapping the woman and one other and transporting them for illegal sexual activity aboard his truck, dubbed the “Twilight Express.” Prosecutors alleged that he also kidnapped and sexually assaulted four other women over a span of two decades, subjecting them to beatings and holding them captive as he drove his truck across the country.

On Thursday, Vafeades, 56, agreed to a plea deal just days before his trial was to begin.

He pleaded guilty to the illegal sexual activity charges. The kidnapping charges were dropped in exchange.

The deal means Vafeades — referred to by local media as the “vampire” truck driver because of the fangs on false teeth he once wore — could face more than 20 years in prison.

In May, he also pleaded guilty to transportation of child pornography, which carries a five-year sentence.

Assistant U.S. Attorney Trina Higgins said she hoped the pleas will help bring some closure to the victims, the Associated Press reported. The agreements also mean victims will not have to testify at trial.

“That’s not something I can comment on, but if they wish to speak at sentencing, they’ll be allowed to, and I hope that we’ll hear some of their voices,” Higgins said, according to the Deseret News.

Prosecutors alleged that Vafeades held four more women captive, which was disclosed in a 2014 federal filing. But charges weren’t filed in those cases because of the statute of limitations, AP reported.

One of those alleged victims was working at a retail store when she met Vafeades around 2000, documents show.

They became friends, and in 2005 she joined him for what she thought would be about a week on the truck, according to a federal filing.

Another alleged victim met Vafeades in 2008 when he was a patient at a hospice facility, prosecutors said. They got married two months later; while driving to Utah, he began assaulting her almost daily, the federal filing reads.

With both women, Vafeades took their identification, beat them, forced them to sleep naked and used a Dremel power tool to file down her teeth, prosecutors alleged. They both managed to escape the truck.

The case that brought the kidnapping and sex slave allegations against Vafeades dates back to May 2013. That year, a 19-year-old relative came to Salt Lake City to work for him on his semi, documents show.

But her first night in the truck, Vafeades engaged in sexual activity with the teen while she slept, documents show. A week after driving on the “Twilight Express” on out-of-state trucking jobs, the 19-year-old relative tried to get away, but Vafeades “grabbed her, hit her and strangled her until she blacked out,” the affidavit reads.

He held her captive for six months, prosecutors alleged, and sexually assaulted her, beat her and threatened to kill her if she left.

Vafeades forbade the 19-year-old from looking at anyone, held her identification cards and had her do paperwork on the truck for which she was never paid, documents allege.

As he did with other women he held captive, Vafeades used a Dremel power tool to file the 19-year-old’s teeth, documents allege. He also used an X-acto knife to chip the teen’s teeth “so she could wear false teeth that he ordered to put over her real teeth,” the affidavit reads. The woman told an FBI agent that he “did not like her crooked teeth and thought she had an ugly smile.”

“Vafeades had his own set of false teeth with vampire fangs on them,” the affidavit reads.

Three days after Vafeades beat and choked the 19-year-old relative, officers at a Minnesota weigh station noticed her bruises. They then found that Vafeades had a 1999 protective order that prohibited him from having any contact with the teen, court filings show.

Lawyers for Vafeades had argued that the protective order was no longer valid, so the 2014 arrest never should have happened, AP reported. But a judge ruled that it was a valid stop.

Officers seized hard drives from his truck, and FBI investigators found child pornography on them, the affidavit reads.

When news reports came out about the arrest in Minnesota, the woman Vafeades allegedly held captive in 2012 came forward. She told investigators about how they met at the Salt Lake City truck stop and how she was held captive for months after that, according to the affidavit.

The two had trucked to Utah, Florida, Nebraska and Texas, and she did trucking paperwork for which she was never paid, the affidavit reads. Vafeades tried to change the woman’s identity, authorities said, allegedly cutting and coloring her hair, keeping her driver’s license and forcing her to marry him.

“He also used a Dremel [tool] to file down one of her teeth,” the agent wrote in the affidavit.

He beat her often and threatened to kill her if she talked to anyone, authorities allege.

Eventually, the woman got away: Four months after she first got into Vafeades’s semi, officers at a Nebraska weigh station noticed her bruises, the affidavit reads.

She told them about an assault in Florida, and battery charges were filed there, according to court documents.

In 2014, CBS affiliate KUTV spoke with that victim, whom the station did not identify.

“Once we got in the truck, I thought we were going out to eat,” she told the station. “We had just got on the freeway, and I said, ‘Why are we going this way? There are no restaurants this way.’ ”

She also described the abuse she suffered.

“He beat me with a belt as if I was a little 2-year-old getting spanked to the point where I should have passed out and died,” she told KUTV.

She continued: “I shouldn’t be here. I should be dead and gone … there’s a higher power, there is a reason why I am here.”

Vafeades will formally be sentenced in November. When he appeared in a U.S. district court in Utah on Thursday, “he politely answered the judge’s questions and read aloud a legal description of the charges, but said little else,” AP reported.