In dramatic closing statements after the last of more than 70 witnesses testified, prosecutors portrayed Peterson as a cold-blooded killer who took the lives of Kathleen Savio in 2004 and Stacy Peterson three years later to keep them from getting his money.
"They are killed so they can't take the witness stand in a divorce proceeding," said Will County Assistant State's Attorney John Connor.
But defense attorneys said the case against Peterson is built on lies.
Savio's death was a tragic accident, they said, and Stacy Peterson may have vanished in 2007, but she's not dead.
"For someone to say five, six, seven, eight, nine times that she's dead doesn't mean she's dead," defense attorney George Lenard said. "The reason she is not here with Mr. Peterson is that she left, and she left with another man."
The former Bolingbrook police sergeant is charged with Savio's death, but no charges have been filed in Stacy Peterson's disappearance. Friday's closing statements marked the first time they said outright they believe he killed Stacy Peterson.
The unprecedented hearing is easily the most extensive use of a state law allowing a judge to admit hearsay evidence in first-degree murder cases if prosecutors can prove a defendant may have killed a witness to prevent him or her from testifying. The law was passed after authorities named Peterson a suspect in the 2007 disappearance of his fourth wife, Stacy, then exhumed Savio's body and reopened her death investigation.
The statements that prosecutors want Judge Stephen White to admit as testimony are those in which the women allegedly expressed to friends and family that they were afraid Peterson would kill them.
Prosecutors want friends and relatives of Savio to be allowed to testify about a threat she described, in which Peterson reportedly held a knife to her throat and allegedly told her he could kill her and make it look like an accident. They also want the judge to allow a friend of Stacy Peterson to testify Peterson had told her he killed Savio.
Defense attorneys argued that many of the statements shouldn't be admitted. For example, they pointed to statements Savio gave police after the alleged knife incident in which Savio never said Peterson had a knife.
"She describes things the way she wants in order to make people feel sorry for her," said Andrew Abood, saying Savio wasn't a credible witness.