In December 1998, police in Pleasant Prairie, Wis., were called to the Lake Shore Drive home of Mark and Julie Jensen. Inside, Mark had found his wife's body lying in her bed.
Initially, investigators thought suicide was a strong possibility. But a letter written by Julie before her death pointed police in a different direction.
Was the husband somehow involved in his wife's death, as the letter hints? Or did Julie poison herself and pen the letter to implicate Mark in a twisted plot gone wrong, as his parents allege?
Pleasant Prairie, Wis. is about an hour north of Chicago, on the western shores of Lake Michigan. It booms in the summertime, but when the Wisconsin winter settles in, the village becomes a cold, bleak place.
No one who lived there was quite prepared for what happened on Dec. 3, 1998.
Special prosecutor Bob Jambois, who at the time was the Kenosha County district attorney, remembers, "My pager went off. I got called to the scene. They told me, 'Well, the M.E. is saying it's probably natural causes but we have some questions, so you might want to come out there.'"
Jambois had a lot of questions about what he found inside the house. "Forty-year-old women don't drop dead for no reason," he explains.
Asked if he had considered that Julie might have committed suicide, Jambois tells correspondent Erin Moriarty, "We absolutely considered that, right from the beginning."
Julie's brothers, Paul, Patrick, Mike, and Larry Griffin, were shocked by the news.
Mark also struggled to explain his wife's sudden death. "He appeared somewhat shaken. And he was rambling on about some drugs that she had taken recently, Ambien and Paxil. And talking about some kind of a drug interaction," Julie's brother Paul remembers.
"Mark was an emotional basket case. He was in tears. He could hardly stand up. He didn't know what to say or he didn't know how to talk," Mark's father, Dan Jensen, remembers.
Mark had been with Julie for 20 years, since they had been high school sweethearts. They started college together, too, but Julie dropped out just one semester short of a degree in nursing.
"She did great with all the book work and everything. She had difficulty because she got very close to the patients. And emotionally she couldn't take it," Paul explains.
What drew Julie to Mark, say her brothers, was his drive: he was a young stockbroker, and on the move.
On April 13, 1984, the night before Mark and Julie got married, Julie's mother June suddenly passed out. "Our mother collapsed at the wedding rehearsal. And we didn't know what the problem was. And as it turned out she was under alcohol withdrawal. So it was very, very disappointing for Julie," Paul explains.
"She told me her mother had ruined everything that was important to her in her life. And if she had a wedding, her mother was going to ruin that, too. And of course, she did," Mark's mother Florence tells Moriarty.
It was the first time that the Jensens realized that Julie's mother was battling alcoholism and depression.
Florence says Julie was afraid she'd end up like her mother. "As she got older, she could feel that she was becoming more like her mother and I'm sure her episodes of depression were part of that," she says.
Shortly after Mark and Julie's first child David was born in 1991, their marriage was rocked by the revelation that Julie had had an affair with another man.
Julie filed for divorce but changed her mind after she and Mark went to counseling. They had another son, Doug, in 1995, but the marriage was strained. By fall of 1998, Mark began telling friends that his wife was depressed
Julie went to see her family doctor, who prescribed an antidepressant. Two days later, she was dead.
With no obvious signs of injury and an inconclusive autopsy, the cause of Julie's death could not be determined.
Her brother Patrick says it's "not possible" that Julie had taken her own life. Julie had never talked about suicide and she didn't leave a suicide note, but, as it turns out, she did leave a letter.