This month marks 30 years since it happened in rural Pontiac.
Joseph Sinnott Edwards is accused of shooting his adoptive parents to death. He is presumably on the run still and wanted for the murders.
But Edwards has eluded capture and eventually the case hit a dead end.
"They worked on that case for a long time, and at some point, a cold case I guess you could say," said Livingston County Sgt. Earl Dutko.
Dutko is now the lead investigator on the case, which has since re-opened since Sheriff Marty Meredith took office in 2010.
Still, the department's most recent sold tip came in 1998. So it's primarily relying on physical evidence like shell casings and fingernail clippings.
"They collected stuff we can use today that really there was no use for when they did it," Dutko said.
Evidence taken from the crime scene has been tested by forensic scientists before, but authorities believe advances in technology could make all the difference.
"I'm hoping we can get more information from those same nail scrapings," Dutko said.
Meredith is asking the Livingston County Board for $20,000 to pay for more testing at a private crime lab in Vernon Hills.
It's one Dutko said is less busy than the state's forensic crime labs.
"Illinois State Crime Labs have a lot of agencies, and a guy can only do so much work in a day," he said.
The hope is more DNA will surface that would help build a stronger case against Edwards, but also catch a possible accomplice.
"There's a warrant for Joseph Edwards. Sure would be nice to find out who that second person is," Dutko said.
Based on writing imprints on a notepad that said something similar to "Joe and a friend," authorities believe Edwards was not acting alone.
The sheriff's office is also using its resources to locate Edwards. It also hopes to capitalize on DNA recently taken from Edwards' birth mother.
County leaders are expected to consider the funding request Thursday.