Brett Darrow rigged a dashboard camera in his car and then recorded a St. George, Mo., police officer who started yelling and threatening the 20-year-old after he stopped in a commuter parking lot.

Sgt. James Kuehnlein is heard on the tape saying that Darrow was "suspicious."

"The attitude escalated when he thought I was questioning his authority, but I was just trying to figure out what he was doing," Darrow tells The Post-Dispatch. "I was really scared. He was up in my face, spit coming in my face."

Here are some excerpts from the tirade that followed:

Officer: You wanna try me? You wanna try me tonight? You think you have a bad night? I will ruin your [expletive] night. You wanna try me? Do you wanna try me young boy? You wanna try me tonight young boy? You wanna go to jail for some [expletive] reason I come up with? You wanna see who knows the law better, me or you?

You can watch the video, which contains offensive language and comes in two parts, here and here.

"I'd like to see the officer fired. I thought his conduct was ridiculous. and now the patrol car video is missing. The chief can't find it, so I think this officer needs to be fired,"  Darrow tells CNN.

Chief Scott Uhrig tells KTVI-TV that Kuehnlein was placed on unpaid leave because he failed to turn on his patrol car's camera during the stop.

"There is some language, certain things said that I don't condone. But at the same time, this guy was pushing the buttons of this officer, antagonizing him purposely," Uhrig tells the station.

Darrow didn't receive a ticket. He says he installed the camera last year after receiving a traffic ticket that he thought he didn't deserve.

Update at 10:44 a.m. ET: Uhrig was less supportive of the officer when he spoke with the Associated Press. "I was very displeased when I saw the actions on the video," Uhrig said. "My officers are not trained and taught to act like that."

He says the officer's behavior was inappropriate. "Someone either violated the law or they didn't. You don't say, I'll lock you up and then come up with why afterward," Uhrig said.