LOUISVILLE, Kentucky - An 18-year-old Kentucky high schooler has pleaded not guilty to second-degree assault and criminal mischief in an assault on a reportedly autistic classmate.

News outlets report Damon Simmons is accused of attacking the Iroquois High student on Thursday with the help of three juvenile students. An arrest citation says surveillance video shows Simmons and the other students enter a bathroom at the Louisville school after the victim. Another student later found the victim lying in a pool of blood in the bathroom.

The victim’s sister told WAVE-TV that her brother is on the autism spectrum. The victim told authorities that he didn’t know his attackers. He has since undergone surgery for a fractured jaw and the loss of several teeth. WLKY-TV reports related charges have been filed against the juveniles.