(NewsNation) — Authorities are continuing to investigate a case that began when a kidnapped woman escaped from a makeshift cinderblock cell and has now expanded to cover multiple states.

Negasi Zuberi allegedly solicited a sex worker and kidnapped her while posing as an undercover cop in Seattle before holding her captive at his Oregon home, 450 miles away until she escaped. Zuberi was later arrested in Reno, Nevada.

Not long after the kidnapping came to light, Seattle law enforcement moved to shut down two motels along a notorious stretch of North Aurora Avenue, an area known for prostitution.

The FBI said that area is where Zuberi found his victim.

A store worker in the area told NewsNation there would typically be 30 to 40 women working along both sides of the street every night.

After the shutdown, there are only a few women out, and none of the ones who spoke with NewsNation knew the kidnap victim.

In an exclusive interview with NewsNation, FBI Assistant Special Agent in Charge Stephanie Shark said Zuberi’s victim is recovering well and assisting law enforcement with the investigation.

Shark said more investigators have been assigned to the case since it appears Zuberi may have victims in up to a dozen states. Based on information and evidence already gathered, the FBI believes they have gotten a serial predator off the streets.

“We have made daily progress on this investigation to include identifying victims, identifying some sites where we can obtain some evidence, and widening the search and connections with law enforcement all across the country,” Shark said.

Shark said getting Zuberi off the streets has also prevented future crimes.

“His behavior had indeed been escalating based on the information that we’ve identified, there is reason to believe that it would’ve continued to escalate. This was not the start of it and this was definitely not the end,” she said.

While Zuberi is in custody pending extradition to Oregon, the whereabouts of his ex-partner are unknown. In a local TV interview, the mother of Zuberi’s children defended him, claiming the cinderblock cell in the Klamath Falls, Oregon home was meant for subleasing and extra income.

The FBI is not saying how many alleged victims have contacted them, but it is likely Zuberi will be facing additional charges for more than just interstate kidnapping.