Arrest made in 36-year-old Douglas County cold case

The case was cracked using genetic genealogy

Elliott Wenzler
Posted 4/20/21

It’s been nearly 36 years since the grisly homicide that left Roger Dean dead took place in present-day Lone Tree. The case — once referred to by the Douglas County Sheriff as “one of the …

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Arrest made in 36-year-old Douglas County cold case

The case was cracked using genetic genealogy


It’s been nearly 36 years since the grisly homicide that left Roger Dean dead took place in present-day Lone Tree.

The case — once referred to by the Douglas County Sheriff as “one of the greatest mysteries” the county has seen — has remained unsolved throughout the decades.

But on March 22, the Douglas County Sheriff’s Office arrested a man from Louisiana for Dean’s murder and kidnapping. 

“This is one of those bittersweet days,” Sheriff Tony Spurlock said in an April 9 press conference. “This is an interesting case, I happen to have been involved with it (since) 1985.”

Michael Jefferson, 64, was arrested by the sheriff’s office following an investigation that used an increasingly popular crime-solving technique called genetic genealogy. The tactic uses a suspect’s DNA and an online database of family heritage data to track people down.

Douglas County detectives used DNA, preserved from the original crime scene, to find Jefferson and later boarded a plane with the man, surreptitiously collecting his used water bottle and confirming his connection to the crime scene, according to his arrest affidavit.

While an arrest has been made, the case, including a threatening extortion letter received by the victim’s family years after the murder, is still being investigated, Spurlock said.

The murder

The morning of Nov. 21, 1985, Roger, 51, and his wife Doris, who was 49 at the time, were just starting their day. Their home on BigHorn Court was, at the time, in unincorporated Douglas County. Today, the area is within the city limits of Lone Tree.

Doris was in the bathtub when her husband called out to her, asking her to come see something on the television, she later told police.

When she entered the bedroom, there was a man in a ski mask pointing a gun at Roger. He told her not to look at him and then directed Roger to duct tape her eyes and hands.

“You’re not going to hurt us?” she heard Roger ask.

“Not if you do what I want,” the man responded, according to Doris’ account, included in the affidavit.

Doris was told to lay on the bed while her husband and the man went downstairs. Eventually, the masked man returned and asked her how much money the family had in their bank account. He rustled through her jewelry box and she told him about the $30,000 in their checking account. 

After the man went back downstairs, Doris heard a scuffle break out between Roger and the masked man, she told police. Gunshots were fired. 

Next door, a 9-year-old neighbor heard the shots and looked out her window. The girl watched as Roger and the man struggled at the entrance to the Dean’s home. She heard more gunshots and saw a man, no longer wearing a mask, flee to a nearby car and drive away, according to the affidavit.

The sheriff’s office responded to a 911 call about the incident and by 8:30 a.m., Roger had been pronounced dead. Detectives, including now-Sheriff Tony Spurlock, investigated the scene. Then, for 36 years, the case remained unsolved. At one point, the story was told on the television show “Unsolved Mysteries.”

An attempted extortion

About 5 years after the murder, Doris began receiving intimidating letters from someone claiming to be the person who killed her husband.

The letter included information only known to investigators, Doris and the Dean’s daughter, Tammy, according to the affidavit. In it, the author demanded Doris pay him $150,000 or they would kill her daughter.

“Do exactly what you are told and one day you will live to see your grandchildren,” according to the letter, included in the affidavit.

Doris received four more letters and several phone calls from the person. With law enforcement and the FBI monitoring the situation, Doris dropped the money at a location in Denver, but the person never picked it up.

While the statute of limitations for this extortion would have expired, it’s still being investigated whether or not Jefferson was the one to send the letter because of the connection to his other charges, Spurlock said.

New technologies in policing

At the time of Roger’s murder, there was hardly any technology available to analyze the DNA found at the scene.

In 2003, when the case was re-examined, the detectives were able to run the DNA found at the scene through CODIS, or the Combined DNA Index System, maintained by the Federal Bureau of Investigation, according to the affidavit. There weren’t any matches in the crime database, which houses DNA sequences for suspects and convicted persons across the country.

In 2018, the necessary technology to solve the case was finally available: genetic genealogy. The relatively new crime-solving technique uses an unknown person’s DNA from a crime scene, matched with genealogical records to find the unknown person.

“It takes a lot of work and time,” Spurlock said of the technique. “It’s very painstaking work.”

In November 2020, detectives found Johnson and verified that he was likely in Colorado at the time of the murder, according to the affidavit.

In February, a team of Douglas County detectives boarded the same flight as Jefferson and when he threw away his used water bottle, they intercepted it. The DNA found on the water bottle matched what was found at the crime scene.

Before Jefferson was arrested, Doris Dean died. Doris and Roger’s daughter, Tammy, is still living but has been asked not to speak with media to avoid jeopardizing the case, Spurlock said. Jefferson’s next court hearing is set for July 22 at 9 a.m.

“The level of dedication shown by our law enforcement partners to get us where we are today is truly remarkable,” said District Attorney John Kellner in the April 9 press conference.

The district attorney’s office is asking anyone who recognizes Jefferson or who may have knowledge of the case to contact their office at 720-733-4500.


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