- Drew Peterson is serving 38-year sentence for killing his third ex-wife, Kathleen Savio
- His fourth wife, Stacy Cales Peterson, is missing
- He also faces a new trial, accused of trying to hire someone to kill the prosecutor in his murder trial
Watch Jean Casarez's CNN Special Report, "Married to a Murderer: The Drew Peterson Story," Saturday at 6 p.m. ET/PT.
(CNN)If you thought wife murderer Drew Peterson was done with the legal system, think again.
Peterson is now accused of trying to murder -- from behind bars -- the prosecutor who put him there. This summer, he's scheduled to be back in a courtroom, this time on two counts of murder solicitation.
Peterson has pleaded not guilty to the charges that he hired someone to kill James Glasgow, a renowned Illinois prosecutor who won the conviction in 2012 that sent Peterson away for 38 years. The former Chicago-area police sergeant was found guilty of murdering his ex-wife, Kathleen Savio.
To this day, questions still loom about Peterson's fourth wife, Stacy Cales Peterson, who disappeared in October 2007.
A CNN special report, "Married to a Murderer: The Drew Peterson Story," takes a fresh look at how Peterson went from a police officer to a convicted killer.
From marriage to murder
As his second marriage was failing, Peterson went on a blind date and met the woman who would become his third wife, Kathleen Savio, in 1992.
Savio's sister, Susan Doman, told CNN's Jean Casarez her sister was swept away by Peterson's charm and didn't realize he was already married when they started dating.
"When she was presented with all the opportunities, the trips, the gifts, and the home and having children, it was too hard to resist," Doman said.
Once Peterson's divorce from his second wife was final, he and Savio married. The couple had two sons.
But what appeared to be a loving relationship turned into a nightmare filled with allegations of physical and emotional abuse.
Doman said her sister got an anonymous letter in 2001 telling her Peterson, then 47, was having an affair with 17-year-old Stacy Cales. Savio was devastated.
When Savio confronted her husband, Doman said it got physical. Hospital records echo what Savio told her sister -- allegations Peterson has always denied.
The marriage was over. By the spring of 2002, Peterson moved in with Cales, buying a house down the street from Savio.
The divorce was contentious. Police were called to the Savio home 18 times for domestic events involving Peterson and Savio.
On March 1, 2004, Savio was found dead in the bathtub. Investigators ruled her death an accident.
By this point, Peterson was married to Stacy Cales, who would have two children with Peterson.
Her aunt, Candace Aikin, said Stacy Peterson knew she had made a mistake by marrying Peterson, but she was trying to make it work.
In addition to her children, she was also raising the sons Peterson had with Savio.
"I could tell that she was under a lot of stress," Aikin said. "She said she couldn't really go anywhere and do things. That he was constantly calling her."
As Peterson had done before, he denied allegations of abuse and blamed his wife. He said they were having problems because Stacy Peterson was having trouble coping with her sister's death.
Aikin recalls the night after the funeral for Stacy Peterson's sister in 2006. She begged Aikin to sleep in her bed.
"And he kept coming in there and wanting her to go ... But she said no, she wasn't going with him and she didn't want me to get out of the bed ... and I was afraid," Aikin said.
Disappearance leads to discovery
On October 28, 2007, Stacy Peterson vanished.
Her disappearance made authorities suspicious about the death of Savio, and weeks after Stacy Peterson vanished, they reopened the case on Savio's death. Her body was exhumed for a new autopsy.
In February 2008, Savio's death was reclassified as a homicide, and just over a year later, Peterson was arrested and charged with murder.
Peterson's defense team thought it was an open and shut case.
"There was no physical evidence. You know, there was no sign of forced entry. There was no fingerprints. No DNA," defense attorney Joel Brodsky said.
While Glasgow claimed Peterson killed Savio, the defense contended that she fell, hit her head and drowned.
The trial went on for more than a month. On September 6, 2012, a jury found Peterson guilty. He was sentenced to 38 years in prison.
Savio's brother, Nick, called the verdict "bittersweet."
"Although we cannot have Kathleen back, we hope she can now rest in peace and that she knows she has had her day," he said, reading out a statement from family. "She will be missed and remembered in our hearts always.
"Stacy, you are now next for justice."
Stacy Peterson is still missing.
Peterson is appealing his conviction as he prepares to encounter Glasgow again.
His trial for one count of solicitation of murder for hire and one count of solicitation of murder is expected to begin in August.