Stacy Peterson has not been heard from since Oct. 28, and her husband, former police officer Drew Peterson, has been under a cloud of suspicion ever since.
Drew Peterson, 53, has maintained he had nothing to do with her disappearance and says that his 23-year-old wife left him for another man.
Stacy's family has posted a voice mail message online that the missing mother of two left with her father on Oct. 17, giving him her new phone number and telling him she loved him. The family believes it is evidence that she was not planning on running away. It's the first time the public has heard her voice.
"Hey dad! It's me, Stacy. I just wanted to call you and tell you I love you," she says in the voice mail.
"The season's coming close and it's very difficult," said Pamela Bosco, the spokeswoman for Stacy's family. "We'd like to have answers before the holidays. That's just what we pray for."
While Illinois State Police use dive teams to search the bottom of canals miles from the Petersons' house, police have served a fourth search warrant to Drew, which outlines in new detail how police might build a circumstantial case against the former police sergeant.
The warrant, obtained by ABC News, focuses on his two cars. It shows that investigators are looking at his Global Positioning System to determine where he went around the days his fourth wife, disappeared and whether there is evidence in those vehicles that he moved the body.
The warrant says police will search Drew's sport utility vehicle and sedan for traces of "any blue plastic, lead weights, plastic shavings, plastic scuff marks, circular impressions or carpet indentations" that would indicate the movement of a barrel-like object or storage container.
Drew's stepbrother Tom Morphey, who was arrested in the mid-1980s for alleged domestic violence, told a friend and reportedly told authorities that he helped Drew carry what he thinks might have been Stacy's dead body from the house in a blue container.
Walter Martinek, Morphey's friend, said Morphey told him that he was suspicious.
"He goes, 'I don't know what to do.' He put his hands on my shoulder and said, 'You can't tell anyone,'" Martinek said. "He had told me that he thinks he may have helped Drew dispose of the body."
Joel Brodsky, Drew's attorney, says the new warrant has convinced him that authorities are building a circumstantial murder case and may not wait to find a body before charging his client.
"The only case that they can build is a circumstantial case. But I think they have almost insurmountable hurdles in doing so. I don't think they'll be able to do it," said Brodsky.