Michael David Barrett has not been charged in the other cases but attorney Marshall Grossman told "Good Morning America" in an exclusive interview that he may have posted as many as 40 videos of other women.
"We have credible, determined evidence that Mr . Barrett did the same thing, not just with Erin, not just with a few others, but with 17 other women," he said. "Most of the rest of them have no idea their images were taken."
Michael David Barrett, a former Illinois insurance executive, pleaded guilty Tuesday to interstate stalking after admitting he secretly taped and then tried to sell nude videos of Andrews shot while she was in hotel rooms.
He could face up to five years in prison but in exchange for his plea, Barrett reportedly would spend no more than 27 months behind bars. Sentencing is scheduled for Feb. 22.
Andrews, Grossman said, will focus on making sweeping changes in the hotel industry.
"She wants the hotel industry to see this as a wake-up call," Grossman said, calling for at least "minimal protection in order to help secure the safety and privacy of their guests.
"Thus far, the industry has been rather lax in doing that."
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Andrews, 31, spoke in a blistering statement in the courtroom Tuesday, telling a federal judge that Barrett was a sexual predator who should "never see the light of day."
After the hearing, Andrews said, "I lost it for the first couple of minutes. I couldn't really keep it together, but I wanted to go in right away because I just wanted to get it over with and just see him."
Barrett's attorney issued a statement after the hearing saying, "He deeply regrets any pain he has caused to Ms. Andrews. At this time, Mr. Barrett looks forward to the future and any opportunity to make positive changes in his life."
That wasn't enough for Andrews.
"I want him to stay in jail as long as possible," she said. "He's a threat to women everywhere. I feel like it was my duty to come here and tell this judge what he has done to me, because I don't want another family to be ripped apart by this. I don't want somebody else's career to be ruined by this."
Police say Barrett made as many as eight separate videos and then posted them on the Internet starting in July.
Examination of a photo of one of the peepholes in a room where Andrews was taped shows obvious signs of tampering, Grossman said, in the form of gouge marks where the peephole had been popped out. He suggested hotel guests put a Band-Aid or a piece of tissue paper over the peepholes in their rooms, just to be safe.
He also called for better training for employees. It "boggles the mind," he said, that Barrett was able to learn where Andrews was staying and in what room without her permission.
"For now, most guests are vulnerable and the industry has to clean its act up," Grossman said.
Andrews told the court she is now routinely subjected to crude remarks by stadium crowds when she is on the job.
Her father, Steve Andrews, was by her side Tuesday.
"We have cried a lot, we talked a lot," he said. "There haven't been a lot of good times in the last several months."