(NewsNation) — More is being learned about Oregon kidnapping suspect Negasi Zuberi’s past, including previous sexual assault cases and sex workers who say they knew to stay away from him.

On Tuesday, NewsNation’s Nancy Loo spoke with multiple sex workers in Northeast Portland, an area known for prostitution, who revealed what they knew about Zuberi. Women say they were afraid to speak up because he allegedly posed as an undercover cop.

“It sucks when the bad guys get away with stuff,” sex worker Elle Stanger said. “It’s very easy for anyone to say ‘come with me.’ If this person has any criminal background, if they have any vulnerabilities, if there’s a huge power dynamic disparity … someone who doesn’t have a lot of rights isn’t going to be able to say no. They’re gonna go with anyone who seems to be an authority figure. These people can fly under the radar when they target people who don’t have a lot of rights.”

Since FBI agents in Oregon announced the case last week, including Zuberi’s ties to 10 states using various aliases, the FBI has been able to determine that he spent time in Chicago in January of 2019 and in Ecorse, Michigan, a Detroit suburb, in April of 2017.

That brings the total to a dozen states where there may be potential victims.

The FBI has not said how many tips about potential victims have come in, but sources told NewsNation information is matching up to the multiple states where he has spent time, along with the rough timeline, which appears to overlap, since he was often on the move.