Investigators search on a farm near Peoria on Saturday for the body of Stacy Peterson after receiving a tip that her body may be dumped there.
An anthropologist who helped search a central Illinois location for the remains of former police officer Drew Peterson's fourth wife said he believes authorities have a solid lead and he's advised them to keep hunting with a device that shows what's underground.
Anthropologist Alan Harn, whose work in 2005 led to the arrest of serial killer Larry Bright, told The Associated Press he excavated three sites Saturday that had been identified by cadaver-sniffing dogs.
He found only opossum bones and no sign of Stacy Peterson, who disappeared in 2007. Investigators suspended their search on a farm near Peoria on Saturday night and didn't expect to start again until after Monday.
Will County State's Attorney's spokesman Chuck Pelkie said the search won't delay Peterson's upcoming trial. Jury selection is scheduled to begin July 8.
Drew Peterson, a suspect in Stacy Peterson's disappearance, is in custody at the Will County Jail awaiting trial in the 2004 drowning death of his third wife, Kathleen Savio. He's pleaded not guilty to first-degree murder in Savio's death, and he's denied involvement in Stacy Peterson's disappearance.
Harn, an anthropologist for the Illinois State Museum, said the tip that led investigators to the central Illinois farm came from "a representative" of someone in jail.
"I think they have a really good tip," Harn said Monday. He declined to say more about what led investigators to the area.
Normally, Harn spends his time unearthing prehistoric American Indian villages near the Dickson Mounds Museum in Lewistown. Before digging started this year, his team used a device called a magnetometer to locate underground house sites in the centuries-old Morton Village.
Such a tool could help investigators find spots where soil has been disturbed when they return to the central Illinois farm, Harn said.
Cadaver dogs won't be of much help, he said, because dogs do well spotting recently buried bodies in shallow graves, but don't perform as well with older, deeper sites.
"Canines are like humans. They're imperfect mechanisms," Harn said.
When investigators asked for his help over the weekend, Harn was told only that it was a high-profile case. He spent about 12 hours at the site Saturday and learned while he was there that he was helping in the hunt for Stacy Peterson. He professes to be interested more in the puzzle of underground evidence that the details of crimes and victims.
"I'm really not interested so much in the case or the person as I am in trying to get information out of the ground that will tell someone what happened here at this particular site," he said.
In 2005, Harn helped locate and identify skeletal remains recovered at crime scenes in central Illinois. His assistance led to the arrest of Bright, now serving life in prison after pleading guilty to eight slayings in the Peoria area.
Earlier this year, he received an Illinois State Police citation for his work in the Bright investigation. The citation said his "devotion to duty removed a dangerous killer from the streets."