John Wayne Gacy (1942–1994) was an American serial killer and sex offender who murdered at least 33 young men and boys in Illinois between 1972 and 1978. Known as the “Killer Clown” due to his public appearances as “Pogo the Clown,” Gacy hid many of his victims in the crawl space of his home. He was convicted in 1980 and executed by lethal injection in 1994.