He probably had a lawyer with enough sense to make him clean up. I've spent a lot of time in the courthouse near me and I see a lot of young guys and gals going on trial wearing jeans and tshirts with shiny slogans. If the judge is used to seeing that all day, a clean shaven well dressed kid might make more of an impression (not defending criminals but they do have a right to try and impress the judge/jury).
"We have repeatedly held that one who is unlawfully assaulted and put in apparent danger of his life or of great bodily harm need not attempt to escape but may repel force with force..." PEOPLE v. BUSH
414 Ill. 441 (1953)
Supreme Court of Illinois.