PORTLAND, Ore. (AP) — A woman who escaped her kidnapper by punching her way out of a homemade cinder block cell at a home in southern Oregon likely saved other women from a similar fate, authorities said, by alerting them to a man they now suspect in sexual assaults in at least four more states.

Negasi Zuberi posed as an undercover police officer when he kidnapped the woman in Seattle, drove hundreds of miles to his home in Klamath Falls and locked her in the garage cell until she bloodied her hands breaking the door to escape, the FBI said Wednesday.

Zuberi, 29, faces federal charges that include interstate kidnapping, and authorities said they are looking for additional victims after linking him to the other assaults. Authorities have not yet said publicly in which states those attacks took place.

“This woman was kidnapped, chained, sexually assaulted, and locked in a cinderblock cell,” Stephanie Shark, the assistant special agent in charge of the FBI’s Portland field office, said in a news release. “Police say she beat the door with her hands until they were bloody in order to break free. Her quick thinking and will to survive may have saved other women from a similar nightmare.”

After the woman escaped from his home in Klamath Falls, Zuberi fled the city of roughly 22,000 people but was arrested by state police in Reno, Nevada, the next afternoon, the FBI said.

Court records did not yet list an attorney who might speak on Zuberi’s behalf. He has not yet been assigned a public defender in Oregon as he’s still being transferred from Nevada, which can take several weeks, said Kevin Sonoff, a spokesperson for the U.S. attorney’s office in Oregon.

A grand jury in Portland on Wednesday returned an indictment charging Zuberi with interstate kidnapping and transporting an individual across state lines with intent to engage in criminal sexual activity. He could face up to life in prison if convicted.

According to the FBI, Zuberi also went by the names Sakima, Justin Hyche and Justin Kouassi, and he has lived in multiple states since 2016, possibly including California, Washington, Oregon, Colorado, Utah, Florida, New York, New Jersey, Alabama, and Nevada.

According to a criminal complaint filed in U.S. District Court in Oregon, Zuberi solicited the woman, identified only as Adult Victim 1, in the early-morning hours of July 15 to engage in prostitution along Aurora Avenue in Seattle, an area known for sex work. Afterward, Zuberi told the woman he was an undercover officer, showed her a badge, pointed a stun gun at her and placed her in handcuffs and leg irons before putting her in the back of his vehicle, the complaint says.

He then drove to his home, stopping along the way to sexually assault her, the complaint says. When they arrived about seven hours after he first encountered her in Seattle, he put her in the makeshift cell built from cinder blocks with a door of metal bars and said he was leaving to do paperwork.

The woman “briefly slept and awoke to the realization that she would likely die if she did not attempt to escape,” the complaint says.

She managed to break some of the door’s welded joints, creating a small opening which she climbed through, Klamath Falls Police Capt. Rob Reynolds said at a news conference.

“She repeatedly punched the door with her own hands,” Reynolds said. “She had several lacerations along her knuckles.”

The victim opened Zuberi’s vehicle which was in the garage, grabbed his gun and fled, leaving blood on a wooden fence she climbed over to escape, the complaint says. She flagged down a passing driver, who called 911.

Two Nevada State Patrol officers tracked Zuberi down at a Walmart parking lot in Reno the next day, July 16, the complaint says. He was in his car holding one of his children in the front seat while talking to his wife, who was standing outside the vehicle. He initially refused to get out of the car when the officers asked and instead cut himself with a sharp object and tried to destroy his phone, according to the complaint. Zuberi eventually surrendered, and the child wasn’t harmed.

Investigators interviewed Zuberi’s wife and neighbors, but authorities declined to say if there was any indication that any of them had been aware of the abduction.

A search of Zuberi’s home and garage turned up the Seattle woman’s purse and handwritten notes, according to investigators. One of them was labeled “Operation Take Over” and included a bullet list with entries that read, “Leave phone at home” and “Make sure they don’t have a bunch of ppl (sic) in their life. You don’t want any type of investigation.”

Another handwritten document appeared to include a rough sketch for an underground structure using concrete blocks, foam insulation and waterproof concrete.

The FBI said Zuberi may have used other methods of gaining control of women, including drugging their drinks. The agency said it was setting up a website asking anyone who believes they may have been a victim to come forward.

The Klamath Falls rental home where Zuberi allegedly took the woman is owned by the city’s mayor, Carol Westfall, and her husband, Kevin, according to property records. The house backs onto a park and is on a residential street, less than a quarter-mile (half a kilometer) from a highway.

Court records show that after Zuberi’s arrest, the couple had him evicted.

“We are shocked and dismayed by what has occurred,” the Westfalls, who declined to comment on their interactions with Zuberi, said in an email. “We applaud the actions of the woman who helped capture this person and prevent him from committing further atrocities.”