UNDATED (AP) - Detective Munch has left the building. Richard Belzer's character John Munch retired on last night's episode of "Law and Order: Special Victims Unit." Belzer has played Munch for more than 20 years, starting with "Homicide: Life on the Street." He left the Baltimore Homicide unit to join the SVU in New York, after the earlier series ended its run on NBC. On last night's episode, Belzer had a brief flashback to his Baltimore days. At the end of the show, he answers the phone by saying "Homicide," quickly correcting himself to SVU. But Munch could be back. His character is starting a new job has an investigator for the district attorney.