A man eating with friends at a South Los Angeles diner was shot and killed by two men who walked into the eatery, gunned him down and wounded the owner as they fled, authorities said. Detectives described the killing as an execution, because the gunmen fired all but one of their shots at the victim, Larue Zamorano, 23, of Los Angeles, Detective Gil Freese said. The two gunmen walked into Mel’s Diner, 2101 W. Mar1953066528firing at Zamorano, Freese said. The gunmen wounded the owner of the restaurant, William Holbert, in the arm as they fled. Zamorano had been arrested twice for investigation of murder in the past, but never convicted, Freese said. He had also been arrested on narcotics charges.