A crane was used to hoist Kathleen Savio's casket from a plot at the Queen of Heaven Catholic Cemetery west of Chicago. Authorities were at the scene supervising, said Charles Pelkie, spokesman for the Will County prosecutor's office.
Savio, who was found dead in her bathtub in 2004, was the third wife of Bolingbrook Police Sgt. Drew Peterson. State's Attorney James Glasgow has said evidence suggests that someone killed Savio and tried to make it look like an accident.
An afternoon autopsy was planned, but results were not expected for days.
Investigators reopened the case into her death after Stacy Peterson, Peterson's fourth wife, disappeared last month. Authorities are hoping Savio's exhumed body can offer clues to how she died.
A coroner's jury ruled Savio's death an accident, even though there was no water in the whirlpool bathtub where the 40-year-old's body was found face-down, her hair soaked in blood from a head wound. Investigators theorized the water had drained.
According to court records, Savio had gotten an order of protection in 2002, alleging a pattern of physical abuse and threats by Peterson.
Peterson's current wife, Stacy, was last seen Oct. 28 and state Police Capt. Carl Dobrich has said her husband is "clearly" a suspect. He said the case is now a potential homicide investigation.
The family of Stacy Peterson has said she feared her husband, was making plans to divorce him and would not have willingly left her children, ages 2 and 4.
Drew Peterson has said that his wife phoned him and told him she had left him for another man. A message for Fred Morelli, an attorney representing Drew Peterson, was not immediately returned Tuesday morning.
He has been relieved of duty and placed on suspension without pay pending completion of an internal affairs investigation and hearing.
After a back hoe and two men with shovels opened the grave, Savio's casket was removed from the ground and placed in a van to take the body for a new autopsy, reports CBS station WBBM in Chicago.
The Will County state's attorney's office received permission from a judge on Friday to exhume Savio's body.
Last week, the coroner said it should have been classified undetermined.
Families of both women hope the exhumation will shed light on lingering questions.
"I think both sides are very happy," said Pamela Bosco, a spokeswoman for Stacy Peterson's family. "I think they'll provide a lot of answers again to the questions we have, and hopefully progress the case faster than it is," reported WBBM.
But a forensic pathologist told WBBM news partner the Naperville Sun that it was doubtful that anything new could be discovered from a second autopsy in the Savio case.
"Quite frankly, in terms of coming up with something different or even of a helpful nature regarding the pathologist process is extremely doubtful," said Dr. Cyril Wecht.
The autopsy of Savio, performed by a Will County corner's forensic pathologist three weeks after her death, details a 1-inch laceration to her scalp consistent with a blunt trauma, and more than 10 bruises and cuts about her body.
More than three years later, all those injuries would be unidentifiable, Wecht told WBBM.