Shank.

SHANK delivers a ruthless vision of forthcoming urban life, where guns have been superseded by knives and are fiercely wielded by aimless youths. Amidst the chaos is the Paper Chazers gang, a rare morally conscious group who trade scavenged food for money. After Chazers gang member, Junior, witnesses his brothers murder, he must decide whether to get revenge or stick to the gangs moral code.