Detectives Cracked a 44-Year-Old Murder Cold Case with a Cigarette Butt. Here's How

A 65-year-old man is behind bars for the murder of a woman some four decades ago.

Kenneth Duane Kundert of Clinton, Ark., is charged with the first degree murder of Dorothy Silzel “while committing and attempting to commit the crime of Rape in the first or second degree” in King County, Wash., according to charging documents obtained by PEOPLE.

Kundert was arrested on Aug. 20 and is being held on behalf of other law enforcement agencies, according to the Van Buren County Sheriff’s Office’s online inmate roster.

Prosecutors requested that bail be set at $3 million ahead of his extradition, per the charging documents.

The 30-year-old single woman, who was a full-time Boeing Aircraft Company instructor and worked part-time at a pizzeria, was found dead inside her Kent, Wash. condominium on Feb. 26, 1980, per the charging documents, which note that she had been “beaten in the head, estranged and/ or suffocated, sexually assaulted and left mostly nude in her home.”

At the time, semen was found on her body and her robe, per the charging documents, which note that “as DNA technology advanced over the years, a male DNA profile was obtained from samples from the anal swab and the robe.”

Then, in March of 2022, the DNA evidence collected from the crime scene and analyzed with updated technology led investigators to pinpoint 11 possible suspects – including Kundert and ten people who were related to him, per the charging documents.

By September of 2023, investigators had honed in on three family members, including Kundert. The trio was being investigated for an assault in Arkansas. 

Kundert had worked in Seattle and in Snohomish County in 1987, although records going further back were not available, per the charging documents. He also had a brother who lived a just 1,200 feet away from Silzel’s condominium.

But detectives had trouble collecting the lynchpin DNA evidence needed to pinpoint him as a suspect. Kundert declined to voluntarily give a sample.

During an interview with detectives discussing the assault case, he smoked through a pack of cigarettes and drank from a water bottle, per the charging documents. But after finishing each cigarette, he carefully placed the butts, as well as the crushed water bottle, in his pocket.

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Now believing Kundert to be the killer, Kent police detectives surveilled him in his hometown in Arkansas.

While smoking in a Walmart parking lot earlier this year, Kundert dropped a cigarette butt into a receptacle. Detectives snatched it from the bin and later matched it in a lab to DNA recovered from the crime scene. 

Kundert has not yet been extradited from Arkansas to Washington to face the charges, according to online records that list him as an inmate in the custody of the Van Buren County Sheriff’s Office.

His arraignment, when he will enter a plea, is slated for Aug. 29 at the Maleng Regional Justice Center in Kent, Wash., according to Casey McNerthney of the King County Prosecuting Attorney's Office.

It was not immediately clear if he has a lawyer to represent him in Washington.