The woman said she thought at first she was being carjacked or kidnapped.
The arrest happened in North Riverside.
But the off-duty officer works in Forest Park.
A lieutenant from the Forest Park Police Department was seen on camera arresting a young woman. She says he never identified himself and had his gun drawn.
A driver passing by witnessed the arrest and recorded it on his phone. He saw the officer pulling 18-year-old Breanna Pantoja out of her vehicle.
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"I'm at a red light; this Jeep cuts me off. And he gets out of the car with a gun, screaming, 'get out of the car. Get out of the car and turn it off,'" Pantoja said. "At first I thought I was getting robbed or something cause I didn't know it was a police officer or anything. All I saw was a gun pointed at me."
She says he told her he was stopping her because she had been involved in a hit-and-run. She says, in fact, her vehicle had spun out on the wet pavement Monday afternoon. But she never hit anything and there was no damage to her vehicle or any property. She says she felt like she was being profiled.
"He didn't say, 'this is the police. Get out of the car.' He didn't show me a badge or anything like that," Pantoja said.
He put her in handcuffs.
ABC7 Chicago is not identifying the officer because it's unclear if he's been disciplined by the Forest Park Police Department.
Pantoja, who was born in Berwyn, says she's grateful passing drivers were looking out for her. She says she has filed a complaint about the officer with the Forest Park Police Department.
"I just hope he's out of here and that won't happen to someone else ever again," Pantoja said.
While not identifying the officer, Forest Park officials released a statement saying, "We take this matter very seriously. We are launching an investigation to examine what happened, and the results will be shared with the public and news media. In the interim, this officer has been placed on administrative leave."
The officer eventually called North Riverside officers to respond. Pantoja says they cleared her of any wrongdoing and let her go. The video, however, has garnered a lot of attention on social media.
"I think he's not safe for the streets. I feel unsafe with him roaming around," Pantoja said.
She says she is considering legal action against the lieutenant.