CHICAGO (AP) — A 33-year-old Chicago man is accused of biting two men in a seemingly random attack as the Arctic Monkeys performed at Lollapalooza earlier this month.

Cook County State’s Attorney’s Office spokesman Steve Campbell says Sergio Vicenteno is charged with aggravated battery in the Aug. 1 attack in Chicago. He has not entered a plea. Vicenteno’s attorney, Michael Gillespie, told The Associated Press Friday that the construction worker did not attack the other men but defended himself.

Prosecutors say Vicenteno bit one man’s shin. When Ben Lenet, a friend of the man who was attacked, intervened Vicenteno bit Lenet’s arm and drew blood.

The 29-year-old Lenet says another friend kicked the attacker, who then calmly walked away.

Lenet says he is taking antibiotics and has been tested for hepatitis and HIV.