Video (05:00) : State leaders of the American Civil Liberties Union released a July 2016 squad car video Thursday of what they say is a law enforcement officer's "disturbing and completely unnecessary ... brutal attack" on a motorist in Worthington who was suspected of initiating a dangerous road-rage encounter that same day and resisting arrest.

State leaders of the American Civil Liberties Union released squad car video Thursday of what they say is a law enforcement officer’s “disturbing and completely unnecessary … brutal attack” on a motorist in Worthington, Minn., who was suspected of initiating a dangerous road-rage encounter and resisting arrest.

The civil rights group is calling for local authorities in southwestern Minnesota to investigate what it alleges is the use of excessive force during the July 2016 arrest of Anthony Promvongsa, 22, of Worthington.

Worthington Police Chief Troy Appel and task force Cmdr. Nate Grimmius responded in a joint statement: “The video, viewed in a vacuum, shows only a short segment of the incident that is the basis of the criminal charges.” The two declined to say more about the officer’s actions.

The video shows Joe Joswiak, a member of the Buffalo Ridge Drug Task Force and a Worthington police officer, pulling over the suspect’s sport-utility vehicle and kneeing the belted-in motorist three times, then throwing punches and an elbow before putting on handcuffs.

Recorded from the dashcam of a second squad car at the scene, the video does not show any resistance by Promvongsa, who went to a hospital for evaluation and was released that day.

“Agent Joswiak’s use of force against Anthony Promvongsa is disturbing and completely unnecessary,” Teresa Nelson, executive director in Minnesota for the ACLU, said in a statement. “We are calling for an investigation of Agent Joswiak’s behavior and for him to be held accountable for his brutal attack … up to and including termination and prosecution.”

Worthington police officer Joe Joswiak is seen pulling over and punching Anthony Promvongsa during a July 2016 arrest.

Nelson said Joswiak has not been disciplined.

Promvongsa, in an explanation released by the ACLU, said, “I was literally blindsided with this unnecessary attack. I immediately pulled over for the Worthington squad car, and before I know what was happening, I was beat and ripped from my vehicle.”

The criminal complaint charges Promvongsa with assault with a dangerous weapon, fleeing police in a vehicle, marijuana possession and driving after his license was revoked.

Kathleen Kusz, the Nobles County attorney, cautioned that the video merely “shows a portion of the evidence that would be presented at trial.”

According to the criminal complaint, Promvongsa caused a road-rage incident that started about 9:30 a.m. on July 28. Promvongsa is accused of endangering an off-duty Worthington police officer, including tailgating, swerving, making hand gestures out the window and speeding up before stopping just short of the officer’s car.

The off-duty officer then met up with a fellow off-duty officer. Promvongsa sped between their vehicles, saying he was “going to get his boys and come back to get them” before speeding off, the complaint said.

After Promvongsa’s encounter with the off-duty officers, Joswiak drove in his unmarked car to where the suspect was last seen and found Promvongsa. The complaint alleges that Promvongsa swerved toward Joswiak and kept going.

Joswiak and another officer, Sgt. Tim Gaul, got Promvongsa to pull over.

The complaint’s version of the arrest says that Joswiak, gun drawn, yelled at Promvongsa to exit the vehicle, which he never did. Joswiak then kneed Promvongsa several times, punched him and pulled him to the street before putting on the handcuffs.

Promvongsa, who is no longer in custody, awaits the scheduling of a trial date. His criminal history in Minnesota as an adult includes convictions for underage drinking, drunken driving and driving on a revoked license.