Drew Peterson, 54, recently proposed to his 23-year-old girlfriend of four months, his publicist confirmed to ABCNews.com, but he will not reveal her identity in an attempt to shield her from the media.
"Yes, Peterson is engaged," said Glenn Selig, Drew Peterson's publicist, who added the proposal occurred "in the past few days." "But we're not saying to who. He's entitled to his privacy and so is she."
The family of Stacy Peterson said that at first they were "shocked" to hear about Peterson's engagement.
"We were shocked when we first heard but then when we thought it through we weren't at all surprised," said Pamela Bosco, the spokeswoman for Stacy Peterson's family. "This is obviously a pattern we've seen with [Peterson]."
Bosco said that Stacy's family believes Peterson must have an ulterior motive for making his engagement public.
"If the engagement was really a private matter he wouldn't have made it public," said Bosco. "Maybe it has something to do with his legal situation or a book deal." In any case, she added, the family believes there must be an ulterior motive that involves money.
"I don't think anything he does right now is really about love," she said.
Asked whether the family had any advice for Peterson's fiancé, Bosco said that the mystery woman has enough information to make a decision about Peterson herself.
"It's not like she's walking into this blinded – there's a lot of information out there to help her make an intelligent decision," said Bosco. "Nothing I could say to her would change her mind."
And as for whether Stacy's family believes Peterson's bride is in danger, Bosco said she's concerned.
"If history repeats itself then I'd say this is not a good situation for her to be in," she said.
Drew Peterson garnered media attention after his wife, Stacy Peterson, 24, went missing Oct. 28, 2007. He was widely criticized for his blase attitude toward his wife's disappearance, even alleging to the press that his wife's PMS had led her to run off with another man.
The case remains open and is under investigation by the Illinois State Police and the Will County State's Attorney Office. A statement released by James Glasgow, Will County state's attorney, said, "I fully expect there to be a resolution in at least one of these investigations in the near future."
Drew Peterson told ABC News in an interview last year that the search for Stacy Peterson was a "waste of time."
On the anniversary of Stacy Peterson's disappearance, Drew Peterson told ABC's "Good Morning America" that he hopes she one day turns up.
"I hope someday she pops her head up and shows herself," he said.
Drew Peterson's legal troubles grew when the body of his third wife, Kathleen Savio, was exhumed and he was named a suspect in her 2004 death, which had initially been ruled an accident. Authorities now believe Savio's mysterious bathtub drowning was a homicide.
But because Drew Peterson is still legally married to Stacy Peterson, a divorce will be necessary before he can set a date to walk down the aisle with his mystery bride.
"He's legally married still," said Selig, "so I guess in order to get remarried he'll need to get a divorce first."
According to the Chicago Tribune, Drew Peterson met with a high-profile divorce attorney to look into how to get granted a divorce on the basis of abandonment.
Who Is Drew Peterson's Bride-to-Be?
With the identity of Drew Peterson's fiancee being kept tightly under wraps, few details have emerged about the woman who was apparently one of six women the former cop had reportedly dated since Stacy Peterson's disappearance.
Derek Armstrong, author of "Drew Peterson Exposed" and a reporter who has followed the Peterson case for more than a year, first broke the news of Peterson's engagement.
According to Armstrong, Drew Peterson's future bride was a former fan of his who first introduced herself to him through handwritten letters.
"I asked him if she was one of his fans," said Armstrong, "and he said 'yes.' He's definitely been getting a lot of fan mail."
Armstrong said that Drew Peterson described his fiancee as "very attractive" and "svelte." At 23 years old, she is one year younger than Stacy Peterson, who would be 24.
When asked by Armstrong about the vast age different, Drew Peterson laughed and said, "I don't care, not my problem."
The fiancee lives about 15 minutes from his home in Bolingbrook, Ill., according to Armstrong, and Drew Peterson has introduced her to his two children.
The couple has not yet moved in together, said Armstrong. While the specifics of the proposal were not disclosed by Drew Peterson or his lawyer, Armstrong confirmed that a ring was involved.
Peterson Shocked at Engagement Leak
While Armstrong described Drew Peterson as someone who has "come to enjoy the media attention" after his wife's disappearance, the former cop claimed otherwise in an interview this morning with the Chicago Sun-Times.
"I can't believe this is happening," Drew Peterson told the paper. "How the f-- did this get out?"
"Last time I had a relationship, you guys screwed it all up," he said.
Drew Peterson is frustrated, said Armstrong, by the media attention but also seems to enjoy it.
"He's definitely frustrated he can't sell the house and he can't get married and the media is watching him," said Armstrong. "He does think that if the name of his fiancee was disclosed it would break up the relationship."
"But he really doesn't care what people think of him, that's the truth," said Armstrong. "He likes to be the center of attention, for sure."
Armstrong said that he asked Drew Peterson about his feelings for his wife, Stacy Peterson, whom after her disappearance he maintained he was still in love with.
"I asked him, 'what about Stacy? Last time we talked you said you're still in love with her,'" said Armstrong.
"[Drew Peterson] responded that 'it's hard to still be in love with her after everything she's done,'" he said.
"He's holding on to his belief that she left him."