Advice for biting 3 year old

Having a huge problem with my 3 year old biting his younger brother. My son is very vocal and we can actually have lengthy conversations about alot of things and have started homeschooling already. Ive tried telling him it hurts his brother (and his brother has bit him in retaliation a couple times so he knows it hurts) but its like he wants to hurt him at this point. If I tell him hes hurting his brother he says he knows and usually says it while laughing. Ive done time outs and restricting the little TV time he gets but nothing. I really am against spanking and physical punishments and it has worked for everything thus far except this. If you had a biter what finally stopped it? Hes able to comprehend hes hurting his brother and thats its not acceptable behavior but choosing to do it anyways.