A police officer who pointed his gun at protesters in Ferguson, Missouri, on Tuesday night has been relieved of his post indefinitely, St. Louis County Police said on Wednesday.

As depicted in a video posted to YouTube on Wednesday, the officer approached a citizen journalist, one who was live-streaming the protests in real time, with his gun raised. The officer can be heard on the video saying, “I will f---ing kill you” and “Go f--- yourself” when asked for his name.

"On Tuesday, August 19, 2014, shortly before midnight, an incident occurred wherein a St. Ann Police Officer pointed a semi-automatic assault rifle at a peaceful protestor after a verbal exchange It was at this time a St. Louis County Police Sergeant walked over and immediately took action, forcing the officer to lower the weapon, and escorting him away from the area,” the St. Louis County Police said in a statement on Wednesday.

The name of the officer has not been released.

News of the suspension comes after the American Civil Liberties Union of Missouri sent a letter to the Missouri State Highway Patrol, asking the police to take action against the offending officer.