Law & Order: Special Victims Unit: Season 8, Episode 4

Uncle

When a mother and daughter are found raped and murdered, Stabler and Beck take in a homeless man who turns out to be Munch's uncle, Andrew, played by Jerry Lewis. Initially he's their main suspect until they find their way to a new suspect, Brent Allen Banks (Timothy Adams). Unfortunately, when their only evidence, a bite mark on one of the victims linked to a suspect in a prior rape case, is thrown out of court the suspect walks. Stabler and Beck follow the suspect in a last ditch scramble to catch him in the act of committing his next rape, but Munch's uncle takes the law in his own hands.