More than 30 years after serial killer John Wayne Gacy was arrested, convicted of murdering 33 young men and boys and sentenced to death, scientists at the University of North Texas Center for Human Identification are working, at the request of Cook County, Ill.,  to identify the remains of eight of those victims who have remained anonymous all these years.

John Wayne Gacy

Arthur Eisenberg, co-director of the identification center at the UNT Health Science Center, located in Fort Worth, told the Fort Worth Star-Telegram that scientists at the have been successful in extracting DNA from the bones of the eight victims but that testing will continue for at least another month. But even after the DNA profiles are complete, Eisenberg noted, they won’t be useful in identifying the unknown victims unless the scientists have something to compare them with.

Family members of young men and boys who are believed to have fallen victim to Gacy but whose remains were not among those already identified are being asked to contribute DNA samples for comparison, and the DNA profiles from the unidentified remains will also be compared to a database of DNA profiles from family members of young men and boys who went missing during Gacy’s six-year killing spree.

Gacy first began molesting young boys in the late 1960s when he lived with his first wife and their two children in Waterloo, Iowa. Eventually, two of the boys reported him to police and in December 1968 he was convicted of sodomy and sentenced to 10 years in prison. His wife divorced him and he never saw her or their children again. He was paroled two years later and moved back to his hometown of Chicago. He killed his first victim in 1972.

Of the 33 young men and boys he is known to have killed, 26 were buried in the crawlspace under his home. Three more were buried elsewhere on his property, and the final four victims were dumped in a nearby river.

Gacy eventually became known as “The Killer Clown,” in reference to the fact that he had joined an organization that dressed as clowns to perform at charitable events and for hospitalized children. Gacy’s clown character was called Pogo The Clown.

John Wayne Gacy was executed by lethal injection on May 10, 1994, at the age of 52.