DNA breakthrough leads to arrest in grisly 33-year-old cold case investigators never gave up on

Investigators spent decades chasing leads and revisiting evidence, but the case remained unsolved.

Now, prosecutors say a breakthrough in forensic genealogy and decades-old DNA evidence finally cracked the case wide open.

"While nothing can erase the pain experienced by Miss Sperino's loved ones, we hope this development provides some answers after so many years," Haine said in a statement.

Authorities say Sperino, 34, was found dead Nov. 9, 1993, in a field in unincorporated Granite City after suffering what court records describe as "massive blunt force trauma to the head."

"Seven years ago, Sheriff Connor had the foresight to know that a new investigative tool, even though it was just emerging, might be able to provide a breakthrough in this investigation," Haine said. "The sheriff and his investigators never wavered in seeking justice in this case."

Haine credited generations of investigators for refusing to let the case go cold for good.

"These tools are only effective because of the dedication, persistence, and professionalism of investigators who are willing to revisit evidence, follow leads, knock on doors, conduct interviews and continue pursuing the truth, no matter how much time has passed," he said.

Court documents allege Zigler later admitted to investigators that he picked Sperino up in Granite City, beat her with a metal bat or steel pipe at his residence and dumped her body in a field.

Zigler has been charged with two counts of first-degree murder alleging he intentionally beat Sperino with a bludgeon, causing her death. Prosecutors are seeking to keep Zigler behind bars pending trial, arguing the charges involve a violent and non-probationable offense.

An arrest warrant filed in Madison County Circuit Court shows Zigler remains in custody.

At an initial court appearance Tuesday, Associate Judge James Hackett appointed a public defender to represent Zigler and scheduled a detention hearing for Wednesday afternoon.

Fox News Digital reached out to the Madison County Sheriff's Office for comment, but did not immediately receive a response.