CHICAGO (CBS) — The Cook County Sheriff’s office has received more lab test results, as they try to attach a name to John Wayne Gacy’s seven unidentified victims.

As WBBM Newsradio’s Steve Miller reports, in all, Cook County Sheriff’s Police Detective Jason Moran has sent off more than 40 DNA samples from the families of 30 missing persons – all of them potential victims of John Wayne Gacy.

LISTEN: WBBM Newsradio’s Steve Miller reports

RELATED: CBS 2 Vault: John Wayne Gacy Speaks

This latest round of test results has just come back, and Detective Moran says there are no matches.

Moran says he was fairly confident that one case in particular stood a reasonable chance of being a match.

“I was,” Moran said. “When I listen to these stories – when I’m following up on these leads – and I listen to families’ stories about a missing loved one, some of them fit the victim profile more than others.”

Detective Moran says even though the families’ missing loved ones were not Gacy victims, the families’ DNA now goes into a national missing persons database.

Gacy, an ex-convict with a history of sodomy convictions, worked as a contractor on Chicago’s Northwest Side and northwest suburbs in the years immediately preceding his arrest. He was a Democratic precinct captain and worked as a clown at children’s parties.

Gacy was arrested in December 1978, after 29 bodies were found in a crawlspace under his house at 8213 W. Summerdale Ave. in unincorporated Norwood Park Township. Four more bodies were found in the Des Plaines River.

After barely two hours’ deliberation in 1979, Gacy was found guilty of 33 counts of murder.

Gacy was executed on May 10, 1994. Notoriously, his last words were, “Kiss my ass.”

Last year, a positive DNA match identified one previously unknown Gacy victim – William George Bundy, who was 19 when he disappeared in 1976.

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