FAIRFAX, Va. (AP) — Authorities in Virginia say a state trooper is under investigation for his forceful actions and words during a traffic stop of a Black driver last year.

The Washington Post reported Wednesday that the trooper can be heard on video telling the driver “you are going to get your a– whooped,” before forcefully removing him from his vehicle.

The attorney representing driver Derrick Thompson wrote a letter Monday to Virginia Attorney General Mark Herring. The lawyer said Trooper Charles Hewitt unconstitutionally assaulted Thompson during the stop on I-495 in Fairfax County.

Virginia State Police said in a statement that they have initiated a criminal investigation. Virginia’s State Police superintendent, Col. Gary T. Settle, said the trooper’s conduct was not in agreement with established standards or characteristic of state police personnel.

Thompson was pulled over for an expired inspection decal. State police said the troopers then learned that he was driving with a suspended license. One of the troopers said he smelled marijuana coming from the car, police said.

State police said Thompson refused to comply with repeated requests to exit the vehicle. The video clip begins with Thompson appearing to passively resist the trooper. The situation escalates with the trooper’s harsh words and him putting his arm around Thompson’s neck and wrestling him out of the car.

Hewitt could not immediately be reached through numbers listed under his name. State police said Hewitt is on administrative leave pending the outcome of the investigation.