She Left a Letter Naming Her Killer Before She Died | True Crime Documentary

And the evidence is abundantly clear that Mark Jensen in a very cold and calculated fashion murdered his wife.  This is a poisoner. A poisoning murder case and poisoners are different breed of murderers.  He started talking about websites that you could go to, um, different poisons that would be non-detectable in a normal autopsy.

 It is just the most cold-blooded case I’ve ever seen.  In the final week of November 1998, Julie Jensen woke up to another cold Wisconsin morning, made breakfast for her two sons, packed their school bags, and moved through the kind of routine nobody thinks could become evidence someday. Across town, her husband Mark Jensen was already at work, a stockbroker, a church-going father.

 To everyone looking in from the outside, they were an ordinary family living an ordinary life in Pleasant Prairie. But behind the walls of that house, their marriage had been quietly collapsing for years, and Julie was scared enough that she told people something chilling. If anything ever happened to her, her husband did it. Nine days later, she was dead.

What investigators uncovered afterward would turn this suburban marriage into one of Wisconsin’s most disturbing murder cases, involving secret affairs, hidden evidence, and a letter written by a woman who seemed to have predicted her own death. At some point in the late morning of December 3rd, 1998, Mark Jensen called 911 from their home at Pleasant Prairie, Wisconsin, a village on the western shore of Lake Michigan, roughly 40 miles south of Milwaukee.

He told the dispatcher his wife was dead. When Kenosha County authorities arrived, they found Julie Jensen lying in the bed she had shared with her husband. 40 years old, two young sons, a smashed nose, her arm twisted at an unusual angle beneath her body. No obvious trauma, no clear cause of death. At the time, no one had any idea how long she had been dying.

Mark told police Julie had been unwell for several days, breathing difficulties, weakness. She had been prescribed the antidepressant Paxil just days earlier, he said, because she was struggling with depression. He said she had asked him not to call for help that morning. He said that when he noticed she had deteriorated overnight, no motor control, barely responsive, he had honored that request.

“I just watched it happen,” he told detectives. Bob Jambois, the Kenosha County District Attorney, was called to the scene personally. He found the position of Julie’s body unusual. He found the smashing of her nose unusual. He found the whole picture, a 40-year-old woman apparently deteriorating for days in a house with no 911 call until she was already gone.

Unusual. But without a clear cause of death, there was not much to hold on to. The initial autopsy came back inconclusive. The medical examiner could not determine cause or manner of death. Julie Jensen, for the moment, remained unexplained. And Mark Jensen went home. Julie Carol Griffin was born in Wisconsin, one of six children.

 She was, by all accounts, the kind of person a community remembers, warm, engaged, unshowy in the way that good people often are. She met Mark Jensen at a Sears where they both worked. She was young, he was charming. They dated through their college years, married in the spring of 1984, and settled into the upscale lakeside neighborhood of Pleasant Prairie.

 The house was just a block from Lake Michigan, the kind of address that suggests everything is going according to plan. While Mark built a career as a stockbroker, Julie had a career of her own. She held a Series 7 license and worked as an administrative assistant at a brokerage firm. Not someone who needed to be taken care of, but someone who had made a deliberate choice to pour herself into her children when they came along.

David arrived in 1990, Douglas a few years later, and Julie became, by all accounts that survives her, a devoted, fiercely present mother. Her brothers, Larry and Paul Griffin, would later describe a woman who lived for her boys, who found her fullness in the ordinary architecture of a day, school pickups, dinners, games in the yard, the kind of bedtime rituals that children carry into adulthood without knowing it.

The coverage of this case, when it came, reduced Julie Jensen almost entirely to a single document, the letter she wrote before she died. And that letter is extraordinary. It should be at the center of this story. But Julie Jensen was not a document. She was a woman who held a professional license, who chose to step away from a career to raise two children, who who lived in a marriage that had quietly become something corrosive and who was still in her final weeks trying to navigate it with her eyes open.

The headlines never mentioned the Siri 7. They barely mentioned the children as people rather than victims. What Julie Jensen was trying to protect in that house was not just herself. It was everything she had built inside it. She was not naive about what her marriage had become. In the early 1990s, Julie had a brief affair with a co-worker. She admitted it to Mark.

 He said he forgave her, but the forgiveness, if it ever existed, curdled. Someone, and it was never conclusively proven who, began harassing the family. Hang up calls at the house, pornographic photographs left around the property, on their vehicles, in the garage. Photographs left on Mark’s car outside his office.

 The harassment went on for years. Julie reported it to police. Police investigated. Nobody was ever charged. And through all of it, the marriage continued. Quieter, more closed off. Two people sharing a house and a life and almost nothing else. Meanwhile, at the brokerage firm where he worked, Mark Jensen was not living the life his wife believed he was living.

Investigators would later discover what colleagues already knew, that sometime before Julie’s death, Mark had begun an affair with a co-worker named Kelly Labont. The emails were in the family computer, clear according to the prosecution and ongoing. Former colleague Kevin Nearing would later testify that Jensen had confided in him about the relationship with Labont.

Nearing said Jensen had spoken about Julie’s affair, the one from years earlier, as a justification, a score he was still settling. Another colleague, Ed Klug, would testify to something far more disturbing, that weeks before Julie’s death, over drinks, Mark Jensen told him he hated his wife, that he had talked explicitly and specifically about ways a person could poison their spouse, substances that might go undetected, how certain chemicals crystallize inside a body after death.

 Mark told me how, um, you know, that that, um, if you wanted to get rid of your wife, that you could go to websites, um, that, um, would tell you how to poison your wife, how to kill her, how it would not be detectable.  Whether Klug took that conversation seriously at the time, he did not go to police, and Mark Jensen went home every night to the house by the lake.

Julie Jensen did not leave things entirely in the hands of fate. In the weeks before her death, she noticed something in Mark’s desk, a shopping list, handwritten. Among the items, a syringe, drugs, chemicals. She took a photograph of it. She kept the photograph. Then, she sat down and wrote a letter, addressed it to the Pleasant Prairie Police Department, and gave it, sealed, to her neighbors, a couple named Pavlik, with instructions that it should be opened only if something happened to her.

“I pray I’m wrong and nothing happens,” she wrote, “but I am suspicious of Mark’s suspicious behavior and fear for my early demise. If anything happens to me, he would be my first suspect.” She also left voicemails for a Pleasant Prairie police officer she trusted, saying the same thing in her own voice. And then, she went on.

 She made breakfast. She drove her boys to school. She moved through the days of her ordinary, increasingly frightened life. There is no way she could have known in those final weeks that the letter would take 24 years to do what she intended it to do. Julie Jensen wrote a letter to the police from inside her own home.

 She addressed it to the department. She gave it to a neighbor for safekeeping. She left voicemails naming her husband. She photographed what she believed to be evidence. Every one of those actions required her to believe clearly and rationally that she was in danger and to act on that belief while still living in the same house as the man she feared.

That is not the behavior of a woman in mental health crisis inventing threats. That is the behavior of someone who assessed her situation accurately and did everything in her power to be heard. The tragedy is not that she didn’t warn anyone. She warned everyone. The question the case eventually forced the courts to answer was whether that warning could survive the constitutional requirements of confrontation.

Whether a dead woman’s words could hold up in a courtroom without her there to defend them. When investigators seized the Jensen family’s desktop computer in the days after Julie’s death, what they found shifted the investigation permanently. Someone in the home had been searching the internet for months.

 The searches, conducted late at night and in the early morning hours, covered poisoning methods, toxins, ethylene glycol, antifreeze, assisted suicide, medical conditions involving low pulse and low blood pressure, and notably, the day before Julie died, someone had searched for those exact conditions. Julie Jensen was dead before noon the following day.

 A computer forensics expert, Jason Ruff, confirmed the search patterns at the 2023 retrial. The searches, he testified, occurred outside normal working hours over a period of several months leading up to Julie’s death. The initial toxicology screen had come back clean, but investigators, now suspicious, ordered secondary blood testing.

 What a forensic toxicologist found this time was unambiguous, ethylene glycol, the primary active ingredient in antifreeze, in Julie’s blood, stomach, and urine. Not a trace amount, not an accidental exposure. The concentration and the distribution across her system indicated that she had ingested the substance over a period of several days.

She had not taken her own life. She had been slowly, methodically poisoned inside her own home. The medical examiner determined a manner of death to be homicide. Prosecutors further alleged that in her final hours, when Julie’s body was failing and she could no longer resist, Mark had pressed her face into a pillow.

The smashed nose that D.A. Jim Bosco had noticed at the scene, the unusual position of the arm, consistent, prosecutors said, with suffocation. Mark Jensen’s response to his wife’s deteriorating condition, by his own account, was to watch. Mark was initially questioned and released.

 Weeks after Julie’s death, Kelly LaBonte moved into the family home. Four months after his wife died, Mark sat down with detectives for a formal interview and insisted LaBonte was just a friend.  Kelly LaBonte was a secretary. Wasn’t it Kelly LaBonte here? You were just a friend.  Mark at this point had no knowledge of the letter his late wife wrote.

 So, police handed it to him and let him alone in the room. You could tell this man is done for at this point. He never saw it coming. He was not charged immediately. Instead, the investigation continued and Mark Jensen with his affair partner now living in the house where his wife had died began building a new life.

 He started a construction company. He married Kelly LaBonte. They had a child together. And then in 2002, four years after Julie’s death, he was arrested for first-degree intentional homicide. Running Mark Jensen’s profile through the lens of his behavior before Julie’s death produced something methodical.

 The harassment that had plagued the home for years, the hang-up calls, the pornographic photographs had been reported repeatedly by Julie. The same email address used to send pornographic material to Kelly LaBonte matched the tag M Jensen. Mark attributed the harassment to Julie’s former affair partner, but that man had moved to North Carolina years earlier and police cleared him quickly.

The computer searches were conducted by someone with access to the family machine who searched deliberately, systematically, and at hours when Julie would have been asleep. Ed Klug’s account, the explicit conversation about poisoning methods before Julie died had gone unreported until he came forward years later in 2006.

Three separate layers of evidence, three separate moments where the pattern was legible if anyone had been positioned to read them all at once. The first trial began on January 3rd, 2008 in Walworth County, Wisconsin moved from Kenosha because of the high-profile nature of the case. It lasted over a month.

 The prosecution led with the computer searches, the affair, and above all else, Julie’s letter. The defense argued she had died by suicide, that she was a troubled woman suffering from depression who had staged her own death to frame her husband. Julie’s brother, Paul Griffin, speaking to media during the 2023 retrial, addressed that argument directly.

 That’s the craziest thing I’ve ever imagined. I don’t know how anyone could believe that, anyone. The jury took 30 hours. On February 21, 2008, they returned a verdict of guilty, first-degree intentional homicide.  Mr. Jensen, it is the sentence of the court that your custody be committed to the Department of Corrections for confinement of the Wisconsin State Prisons without possibility of parole for the remainder of your life.

 You may be seated.  A juror later told CNN that the letter had served as a road map to the murderer. Mark Jensen was sentenced to life in prison without the possibility of parole. He appealed. What followed was 24 years of procedural warfare. The central question became constitutional. Under the Sixth Amendment, a defendant has the right to confront witnesses against them. Julie Jensen was dead.

 She could not be cross-examined. Her letter and her voicemails had been admitted into evidence over the defense’s objection. The Wisconsin Supreme Court, after years of back and forth, ultimately agreed the evidence could not stand. The conviction was vacated in 2021. A new trial was ordered, and the letter and voicemails were excluded entirely.

The retrial began January 9, 2023, before Kenosha County Circuit Court Judge Anthony Milisauskas. This time, without the letter. Prosecutors built their case from what remained. The computer searches, the emails to Kelly Labont, now Kelly Brooks, having since divorced Jensen. The testimony of Ed Klug, who described Jensen’s explicit conversation about poisoning methods.

 The testimony of jailhouse informant Aaron Dillard, who said Jensen had confessed to pressing his wife’s face into a pillow. The toxicology, the forensic pathology. The defense again argued suicide. Dr. Lindsay Thomas testified for the defense that Julie Jensen’s death was most likely self-inflicted. The jury deliberated for more than 6 hours.

 On February 1, 2023, nearly 25 years after Julie Jensen was found dead in her bed, they returned the same verdict. Guilty.  We, the jury, find the defendant Mark D. Jensen guilty of intentional homicide of the first degree as charged in the information.  On April 14, 2023, Judge Milisauskas sentenced Mark Jensen to life in prison without the possibility of parole.

For the second time. The second conviction is in some ways more significant than the first. The first conviction relied heavily on a letter, a piece of evidence so powerful it may have done the jury’s work before the trial began. The second conviction was built almost entirely from circumstantial and testimonial evidence, computer searches, emails, a colleague’s account of a conversation about poison, a forensic toxicology report.

 A jury heard that evidence without the letter, deliberated for 6 hours and reached the same conclusion. What that says is not simply that Mark Jensen is guilty. It says that the evidence apart from the letter was always sufficient, that two decades of appeals, two trials, the full weight of constitutional litigation, and the answer at the end of it was the same.

The letter was real. It just turned out the rest of the case was real, too. Mark Jensen’s thread ends at the courtroom door. He was led out in handcuffs on February 1, 2023. On April 14, he heard the sentence read for the second time in his life. He told reporters after the verdict he intended to appeal.

 As of sentencing, he was 63 years old. He has been incarcerated since July 2007. He remains so. His thread ends. Julie’s does not. Her brothers, Larry and Paul Griffin, stood outside the Kenosha County Courthouse on February 1, 2023, holding a book of photographs. Julie in life, Julie laughing, Julie the way she was before any of this. Larry Griffin spoke to reporters not about the conviction, but about who her sister was.

Julie Jensen was 40 years old when she died. She had two sons she had chosen deliberately to make the center of her days. She had a career she had set aside not because she was asked to, but because she wanted to be present for David and Douglas in a way that mattered to her. She had a mind capable enough to hold a Series 7 financial license and the kind of emotional intelligence to know in her final weeks exactly what was happening to her and to try to do something about it.

She wrote a letter. She made recordings. She gave them to neighbors. She did not pretend. She did not hope quietly. She said his name out loud in writing on record and asked the people around her to remember it. The letter could not be used against him in the end, but it told the world everything it needed to know about who Julie Jensen was.

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