(Photo: YouTube)

On Tuesday, the Sacramento Police Department announced that it would formally begin investigating one of its police officers who was caught on camera slamming a black man to the ground and beating him.

The man’s crime was simply that he was jaywalking.

The video was released on Monday and shows the officer confronting Nandi Cain Jr. after Cain attempts to cross an intersection. The officer argues with Cain in the middle of the street before grabbing him and throwing him to the ground, where he punches Cain in the head.

Naomi Montaie, who was a witness to the incident and recorded it to post it to Facebook, can be heard screaming, “Oh my God! Why’d you take him down like that? No! That was wrong!”

According to the police department, the incident began when the officer “attempted to detain a pedestrian for allegedly unlawfully crossing the street.” However, Cain then “questioned the officer’s validity to stop him at which time a violent encounter occurred between the officer and the pedestrian.”

“For an unknown reason, the officer threw the pedestrian to the ground and began striking him in the face with his hand multiple times,” the SPD statement said.