CHICAGO – Detectives who have long wondered if John Wayne Gacy killed others besides the 33 young men he was convicted of murdering may soon get to search for bodies underneath an apartment complex where his late mother once lived, a law enforcement official said Saturday.

Frank Bilecki, a spokesman for Cook County Sheriff Tom Dart, confirmed a Chicago Sun-Times report that Cook County State’s Attorney Anita Alvarez agreed to ask a judge for a warrant to search the housing complex on the city’s Northwest Side.

Such requests for search warrants are routinely approved.

Dart has been pushing Alvarez’s office for months to sign off on the warrant, but Bilecki said the sheriff’s office was asked for more evidence.

Dart’s office then found records showing that Gacy, a contractor, had done handyman work at the complex, and it located witnesses whose sworn affidavits raised intriguing questions about Gacy’s activities there.

“These people in their affidavits stated that he was seen at odd hours doing odd jobs around the building,” Bilecki said.

Bilecki said that investigators would bring in high-tech thermal imaging devices that detect underground anomalies indicating something may have been buried. At the same time, searchers would bore holes in the ground and have FBI cadaver dogs sniff the holes’ openings for the scent of human remains.

“It should initially be a pretty non-invasive [search],” said Bilecki, adding that the search could become much more involved if the initial search indicates any sign of human remains.

A search would be the latest twist in one of the most terrifying crime sprees in American history, one that ended when investigators discovered 29 bodies buried in the crawlspace of Gacy’s Chicago-area home and yard in the 1970s.

Gacy, who was  arrested in 1978, convicted in 1980 and executed in 1994, has been the subject of countless articles and books, as well as at least one movie.

Gacy’s case has remained in the headlines thanks largely to Dart, who has been trying to identify the remains of still unknown victims and who has voiced questions about whether there may be victims whose remains either haven’t been found or haven’t been linked to one of the most notorious serial killers in American history.

A few weeks ago, the sheriff’s department announced it was submitting the DNA of Gacy and other condemned murderers who were executed in Illinois to a national database in the hopes of clearing the coldest of cold cases across the country. Detectives say that because Gacy traveled extensively, he may have killed people in other locations.

Dart previously exhumed for DNA testing the remains of young men whose bodies were found in Gacy’s crawlspace but never identified, an effort that led to the identification of one of the young men.

The apartment complex was searched in 1998, and more than a dozen underground anomalies were located, but for whatever reason, not all of those sites were investigated further, Bilecki said.