Teen And Her Boyfriend Stab Mother 27 Times, Stage Scene To Look Like Sexual Assault

Murders A-Z is a collection of true crime stories that take an in-depth look at both little-known and infamous murders throughout history.

When authorities in Georgetown, Kentucky, responded to a 911 call at the home of Diane Snellen and her 17-year-old daughter, Stephanie Olson, they were met with a gruesome crime scene. Upstairs, 41-year-old Snellen lay almost completely naked in a massive pool of blood from numerous stab wounds.  

While police initially thought Snellen may have been murdered by a home intruder, they soon realized the killer lived under the same roof as the victim. 

Born Diane Marie Morgan in 1961, she grew up in a small town in Michigan’s Upper Peninsula. She was the oldest of three children raised by a single mother and was known for her boundless energy and spirit.  

“She was eternally upbeat. I don’t care how bad crap was going, she managed to find a ray of sunshine in all that,” former husband Danny Snellen told “Snapped,” airing Sundays at 6/5c on Oxygen.  

Diane had always wanted kids, and she started a family at 20, when she married a man named Stephen Olson. She moved to his hometown of Sheridan, Wyoming, and they had two children, a boy, Stephen Jr., and a girl, Stephanie.  

“Stephanie was a sweet kid, a loving kid. She loved attention,” Danny told “Snapped.”  

A new job moved the Olson family to Versailles, Kentucky, but by that time, Stephen and Diane’s marriage was starting to come apart. They would eventually divorce, and Diane retained custody of both children. She settled 20 miles away in Georgetown, which was close to her new job at the Toyota Motor Manufacturing Kentucky plant.  

At Toyota, Diane began dating co-worker Danny Snellen, and following a whirlwind romance, they were married on New Year’s Eve 1991. Their relationship, however, did not make it past eight years, and they divorced just before the new millennium. 

A single mother again, Diane continued to raise her youngest, Stephanie, at home after Stephen Jr. moved out. 

“Stephanie was very well taken care of,” friend Gale Schenimann told “Snapped.” “She had anything and everything she ever wanted or needed, and Diane, her first concern was Stephanie.” 

But as Stephanie entered her teens, the mother and daughter began butting heads.  

“From the conversations that I had with the people closest to Diane, they said Stephanie was manipulative, at some times very aggressive and violent, very confrontational with her mother,” Georgetown Police Detective Tom Bell told “Snapped.” “[She] wanted to live her own life and not have any interference from Diane.” 

Pretty soon, most of their fights revolved around Stephanie’s new boyfriend, 18-year-old David Tyler Dressman. Diane disapproved of the relationship and the influence she felt Dressman had over her daughter, according to “Snapped.”   

“Diane was definitely not a fan. I don’t think he was the person that she thought was gonna be right for Stephanie at this point in her life,” Prosecutor Lee Greenup told “Snapped.” 

A month before her murder, Diane filed a missing persons report after Stephanie and David ran away to Florida together. They got as far as Georgia before they were caught and sent home.  

Looking to jumpstart her life as an adult, Stephanie graduated from high school a year early in the spring of 2002.  

“Her mom had a graduation party for her and made a big to-do about it. She was a very caring lady,” said Schenimann.  

The celebration, however, didn’t last long. The two had a major blowout when Stephanie said she wanted to move out, and Diane refused. Because Stephanie was a minor, she had no choice but to listen to her mother. 

As Stephanie fretted about the situation, Dressman told her they "would take care of that problem," according to court documents. Soon, Stephanie and David were plotting Diane’s killing.  

To aid them in their murderous plot, the young couple sought the advice of Timothy Wayne Crabtree, who had recently moved to the area from North Carolina.  

“Crabtree was semi-notorious at that point and someone that he knew was alleged to have been a serial killer in another state,” Greenup told “Snapped.”  

Dressman asked Crabtree a “hypothetical question” about how best to kill someone without making any noise, and Crabtree told him to stab the person in the lungs so they couldn’t scream, according to Georgetown, Kentucky, newspaper the News-Graphic.  

Dressman and Stephanie lured Crabtree into their murder plot with the promise of Diane’s life insurance money, of which Diane stood to gain $200,000, according to court documents. 

On the night of June 5, 2002, Stephanie and Dressman stayed over at friend Gale Schenimann’s house. Diane called Stephanie and ordered her to come home, which she refused. 

“According to Zac Greer (Schenimann’s boyfriend), Stephanie slammed the phone down and said, ‘I just wish she would go ahead and die,’” Greenup told “Snapped.”  

Greer would later testify that twice that night, Stephanie and Dressman left the house for extended periods of time, according to the News-Graphic.  

After arriving home the following day, Stephanie called 911.  

“Where is your emergency?” the dispatcher can be heard saying on recordings obtained by “Snapped.”  

“Um, either my mom killed herself, or somebody came and murdered her,” Stephanie said. 

“What makes you think that she's dead?” the dispatcher asked.  

“Well, 'cause she's laying in a puddle of blood in my room,” Stephanie replied. 

When officers with the Georgetown Police Department arrived at the home, they were shocked by the gruesome crime scene. 

“Diane was on her back on the floor. Her legs were spread. She was nude from the waist down. Her pajama top was open,” Detective Tom Bell told “Snapped.” 

“She had a lot of bruises and defensive wounds,” he added. “It looked like she had fought her attacker. My first thoughts were maybe she interrupted a burglar. Somebody came in, assaulted her, raped her and left.”  

The home, however, showed no signs of a break-in, and despite detectives’ initial impressions, there was no evidence of a rape or sexual assault. An autopsy report later revealed Diane was stabbed 27 times, according to Louisville’s Courier-Journal newspaper. One wound pierced her chest cavity and came out her back, and at least nine of the stab wounds were to her head.  

“One of those was a nine-inch wound. The coroner described it as an attempted scalping,” Greenup said.  

As detectives began investigating the crime, they learned of Diane and Stephanie’s contentious relationship, Diane’s life insurance policy and Crabtree’s involvement. They theorized that on the night of the murder, Dressman and Crabtree went with Stephanie to her house, and she confronted her mother. 

“Crabtree’s outside, keeping watch, while Stephanie goes in the house. Stephanie storms upstairs into her room. Diane follows,” Bell told “Snapped.” “Once Diane gets upstairs and Stephanie and her get into an argument, David comes in from behind, and now they’ve got Diane trapped inside Stephanie’s room. The fight ensues, the knife comes out.” 

After killing Diane, authorities believe they staged the crime scene to make it look like a sexual assault, washed the blood off themselves, discarded the murder weapon and waited until the next day to report the crime.  

Dressman and Crabtree were taken into custody in April 2003 and charged with first-degree murder and burglary, according to the News-Graphic. As Stephanie was a minor at the time of the slaying, her case first had to go through juvenile court and then be presented to the grand jury. 

Ten months later, she was arrested and charged with complicity to murder. 

Crabtree pleaded guilty to conspiracy to commit murder in exchange for a six-year prison sentence, according to “Snapped.”  

Stephanie was found guilty of complicity to murder her mother in May 2005, according to the News-Graphic. She wept upon hearing the verdict and was sentenced to 25 years in prison.  

A year later, Dressman was found guilty of complicity to murder and complicity to commit first-degree burglary, according to “Snapped.” He was sentenced to 20 years for complicity and 10 years for burglary, reported the News-Graphic.  

To learn more about the case, tune in to “Snapped” on Oxygen.