CHICAGO (CBS) — Cook County Sheriff Tom Dart has made a new request to the state’s attorney’s office to search the backyard of a Northwest side apartment building in hopes of finding new evidence in the murders of serial killer John Wayne Gacy.

The sheriff’s office confirms they want a warrant to dig on the property in the 6100 block of West Miami Ave. where Gacy worked as a maintenance man.

A similar request made earlier this year was denied for a lack of probable cause of a crime at that scene.

A 1998 dig on the property turned up nothing.

Back in July, Sheriff Dart told Newsradio, “I’ve read, I think, four more affidavits from people who bring new evidence or more substance to existing evidence as to why it would be a good thing to do.”

Dart exhumed the skeletons of several unidentified Gacy victims last year in the hopes DNA could help identify them.

The inquiry led to the identification of one victim, William George Bundy, a Chicagoan who disappeared at age 17.

Gacy was arrested in December 1978, after 29 bodies were found in a crawl space under his house at 8213 W. Summerdale Ave. in unincorporated Norwood Park Township.

Four more bodies were found in the Des Plaines River.

He was executed in 1994

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