John Wayne Gacy murdered at least 33 young men and boys in Norwood Park Township, near Chicago, Illinois. He committed all of his known murders inside his ranch-style house. Gacy had previously been convicted in 1968 of sodomy of a teenage boy in Waterloo, Iowa, and was sentenced to ten years' imprisonment, but served eighteen months. He murdered his first victim in 1972, had murdered twice more by the end of 1975, and murdered at least thirty victims after his divorce from his second wife in 1976. The investigation into the disappearance of Robert Piest led to Gacy's arrest on December 21, 1978. His conviction for thirty-three murders (by one individual) then covered the most homicides in United States