Police have identified and arrested the teen accused of assaulting a CAPA teacher last Thursday in downtown Pittsburgh.

According to police, the victim, Jim Addlespurger, was walking on Tito Way near Exchange Way around 3:30 p.m. when an attacker walked up behind him and struck him on the head, causing him to fall to the ground unconscious.

On Tuesday, police said they issued an arrest warrant for the suspect. Police said he was charged with simple assault.

Sources told Channel 11’s Julie Fine that the boy’s parents brought him to police, and the boy admitted to the crime.

"This was just a random act of violence. (The juvenile) stated he was just having a bad day and that day he didn't care. In the course of walking through the alley way, he saw the victim and decided this was the course of action he was going to take," Cmdr. Eric Holmes said.

Police said a witness saw the incident, aided Addlespurger, 50, and alerted police.

When officers arrived, Addlespurger, who students described as a well-liked English teacher, had contusions and lacerations on his face, head and hands and appeared to be dazed. He could not remember or explain what happened to him.

Authorities reviewed surveillance footage from a nearby camera system and it showed the assault exactly how the witness described it.

Authorities said if the attacker knew Addlespurger, he could be facing up to 20 years in prison.

“If he was attacked, because he is in a protected class which a teacher is in, it’s an automatic felony,” defense attorney Frank Walker said.

According to police, the boy was charged as a juvenile, and taken to Shuman Juvenile Detention Center.

Police said none of the other boys in the video are facing charges.

Former Washington County District Attorney Steve Trapani said when he watches the video, he sees six males move toward the victim and no one offer aid after he was hit.

Channel 11’s Alan Jennings asked police if they suspect the boys were mimicking a roving knockout game, similar to attacks nationwide, where participants seek to knockout a middle-aged person with one punch.

“Not to my knowledge,” Holmes said. “Throughout the investigation, that’s something that the detectives will look in to.”

District Attorney Steven Zappala said he plans to seek to institutionalize the juvenile for a long time. He also praised the cultural district for installing surveillance cameras.

Addlespurger was originally taken to UPMC Mercy Hospital in fair condition. Channel 11’s Alan Jennings reported Tuesday that Addlespurger plans on returning to school sometime next week.