From PEOPLE Magazine Click to enlarge
Though she has been missing since October 2007, Drew Peterson's fourth wife, Stacy, helped convince a Joliet, Ill., jury to convict the former cop of murdering his third wife, Kathleen Savio, in 2004. "Harry Smith, an attorney, testified Stacy told him Drew killed his third wife," says juror Ron Supalo Jr. According to Smith, "she knew how he did it and how he got away with it. We believed Stacy."

A serial smirker on TV, Peterson, 58, showed no emotion when the Sept. 6 verdict was read. "Drew is fine," says defense lawyer Joel Brodsky. "Whatever is sent his way he can handle as long as his kids are good." (His children with Stacy, ages 9 and 7, are living with their half brother Stephen, 33.) Led to the Will County jail, Peterson, says Brodsky, quipped to guards, "'Well, this is going to mess up my plans for Christmas.'"

But hearing "Guilty" shocked the family of Savio, whose death at age 40 had initially been ruled accidental and was investigated as a homicide only after Stacy, 23, vanished. "You can finally rest in peace," her half brother Nicholas Savio, 30, says he later whispered at her grave. "Your coward killer has been brought to justice."

Peterson appeared confident he would never be convicted. At the time of Savio's death, he claimed to have found his estranged wife drowned in a bathtub in her Bolingbrook, Ill., home. He stuck with the story after authorities exhumed her body and a second autopsy showed that she had struggled. He remained so self-assured that in August, when Judge Edward Burmila considered granting a mistrial after prosecutorial missteps, Peterson, who faces up to 60 years in prison, requested that the trial continue.

Now Brodsky says they will appeal. "It's a dark day in America when you can convict someone from hearsay evidence," he says. Meanwhile state's attorney James Glasgow vows to pursue Stacy's case "aggressively," hinting he will release more about her disappearance at Peterson's Nov. 26 sentencing. It is something her family has longed to hear. "Game over, Drew," says Stacy's sister Cassandra Cales. "It's time to pay."