TKO by Tom Schreck

After twenty-five years in prison for murdering a couple of cheerleaders, a quarterback, and the class president, "Hackin'" Howard Rheinhart gets discharged. His case is assigned to Schlitz-drinking, Elvis-loving social worker and pro boxer Duffy Dombrowski. Soon, local high-school VIPs start showing up dead and Howard is nowhere to be found.
Duffy throws himself into Howard's defense while juggling a few problems of his own-like a huge upcoming boxing match, a new hormonal girlfriend, the unsolicited devotion of a goofy karate kid, and the ongoing misadventures of Allah-King, Duffy's Muslim basset hound.