Peterson was 23 when she disappeared Oct. 28, 2007, shortly after telling her church pastor her husband, Drew Walter Peterson -- once named the Bolingbrook Police Department's "Police Officer of the Year" -- had killed his third wife and she feared for her own safety.
Stacy Peterson's sister, Cassandra Cales, reported Stacy missing after failing to hear from her. Cales told police she suspected Drew Peterson had killed her sister, just like she believed he killed his third wife, Kathleen Savio, found drowned in a dry bathtub March 1, 2004.
Drew Peterson, now 56, proclaimed his innocence and claimed Stacy had left him for another man.
He was indicted in Savio's death May 7, 2009, with bail set at $20 million.
As he was arrested, Peterson joked, "I guess I should have returned those library books."
Peterson has been in near-solitary confinement for a year and a half while an appellate court decides what hearsay evidence can be used against him at trial.
His lawyer, Joel Brodsky, told The (Joliet, Ill.) Herald-News he doubted the state would charge Peterson with Stacy's death.
"If (prosecutors) can't convict Drew Peterson on the stronger case, they won't charge him with the weak one," Brodsky said.
State attorney's office spokesman Charles B. Pelkie told the newspaper he could not comment on any plans to indict Drew Peterson in Stacy Peterson's disappearance.