A Texas cop is under investigation after using a stun gun on an elderly man he had stopped for an inspection sticker issue that the officer himself apparently didn't understand.

Dashcam video from the incident posted by Raw Story, above, shows officer Nathanial Robinson, 23, pull over Pete Vasquez, 76, at Adam's Auto Mart in Victoria, Texas, as "Under Ground Kings" by Drake blares from the cruiser's radio.

Vasquez gets out of the car, walks behind it and gestures toward the license plate and to the office of the dealer, where he works. He later told the Victoria Advocate newspaper that he was explaining that the dealer tags on the car make it exempt from inspection.

Victoria Police Chief Jeffrey "J.J." Craig confirmed to the paper that the car was exempt.

On the video, however, Robinson appears to try to snatch a piece of paper from Vasquez without success. Then, he grabs Vasquez's arm, twists it behind him and pushes him against the hood of the cruiser. After a brief scuffle, the cop reaches for both of Vasquez's arms and drags him the ground, out of camera range.

When the cop is next seen in frame, he's yelling and holding up a stun gun.

Police told the newspaper that Robinson used the device twice on Vasquez.

A man emerges from the dealer's office and yells at the cop.

"I told the officer, 'What in the hell are you doing?' This gentleman is 76 years old," sales manager Larry Urich told the newspaper. "The cop told me to stand back, but I didn't shut up. I told him he was a goddamn Nazi Stormtrooper."

When other officers arrive on the scene, they ask Vasquez for his side of the story and check to see if he's injured.

"Are you hurting anywhere?" the unidentified officer can be heard asking on the video.

"Not yet," Vasquez replies. "Probably later on. I'm 76 years old."

Vasquez was taken to a hospital, then released without being cited.

Craig later apologized to Vasquez.

"Public trust is extremely important to us," Craig said, according to the Advocate. "Sometimes that means you have to take a real hard look at some of the actions that occur within the department."

He told The Associated Press that Robinson has been placed on administrative duty pending an investigation.

District attorney Stephen Tyler told the paper he hasn't been contacted by police yet, but said the officer could face charges including official oppression, injury to elderly, aggravated assault and assault.

As many took to the department's Facebook page to express their concern, the agency posted a response reiterating that the incident is under investigation.

"We place incredible value in public trust and have worked diligently to build that trust. In the interest of transparency, and knowing that many of you are looking for an outlet to express your feelings on the matter, we are creating this post to allow your comments to be heard," the post said. "All we ask is that your comments stay within our established posting policy."