MINNEAPOLIS (WCCO) – Minnesota’s American Civil Liberties Union is demanding an investigation into what it called a brutal attack by an officer. Video of an arrest in Worthington last summer shows a Buffalo Ridge Drug Task Force agent opening an SUV door, then kneeing and punching the driver. But authorities say that video only captured a small part of what led to charges against the driver.

The dashcam video shows police pulling Anthony Promvongsa over and an officer approaching the SUV.

READ MORE: Firefighters Hurt By Falling Porch During Minneapolis House Fire

“This is an example, a text book example of excessive force by police. It was really a vicious attack on this young man, it was not just an arrest but it was really an attack, a beating, an assault,” Gordon said.

According to the criminal complaint, Promvongsa caught the attention of an off-duty officer by following closely, speeding past him and later saying “he was going to get his boys and come back to get them.”

The officer believed Promvongsa was attempting to harm him and another off-duty officer. They called dispatch.

Worthington officer and Drug task force Agent Joe Joswiak then tried to pull Promvongsa over, but said he wouldn’t stop at first. The video picks up what happened next.

READ MORE: Willis' 3 Keeps Gopher Men Unbeaten, Beating Bulldogs 81-76

The ACLU wants an investigation into Agent Joswiak’s actions and is calling for his termination and prosecution.

“Police have a very important job to do and valuable job to do, to enforce the law and to protect people, it is not their job to take punishment into their own hands and whoop on people,” Gordon said.

In a statement Promvongsa said he is scared of future interactions with police and, “I did not even have the opportunity to take off my seat belt before I was literally blindsided with this unnecessary attack.”

Promvognsa was driving with a revoked license. He’s charged with using his car as a weapon and fleeing an officer. A trial date has not been set. The law enforcement agencies involved ask people to be “patient as the criminal case progresses.”

Promvognsa’s defense attorney Virginia Barron made this statement:

MORE NEWS: First Major Snowfall Brings Avalanche Of Wintery Pics

Mr. Promvongsa has pled not guilty to the criminal charges in his criminal case and maintains his presumption of innocence. Ms. Delaney and I have been appointed to represent him and we intend to do zealously do so within the confines of the law. As to the video which was released by the ACLU today I do not wish to comment as it relates to the impending criminal case but what I can say is that while there are definitely a number of honorable police officers in the community who are highly respected, the defense bar has seen an increasing systemic problem of excessive force from law enforcement in the Worthington Police Department, Nobles County Sherriff’s Office, and Buffalo Ridge Drug Task Force that should never be allowed or tolerated in a civilized society.