DNA from cigarette helps identify suspect in 2003 cold case death of mother of 7 found in state park

ISLAND COUNTY, Wash. (TCN) -- Investigators recently identified a suspect in the death of a mother of seven that occurred over two decades ago, but officials cannot prosecute him because he now suffers from advanced dementia.

According to the Island County Sheriff’s Office, on Dec. 9, 2003, 39-year-old Tammy Mattson’s body was found in vegetation at Camano Island State Park. Authorities pursued leads and interviewed acquaintances, but they were unable to identify a suspect at the time, and the case went cold.

In 2009, investigators developed DNA profiles using small amounts of human biological matter from a cigarette butt recovered in a parking lot near where Mattson’s body was found. As a result, they discovered a DNA match with 69-year-old Carl Schlobom. Because the DNA on the cigarette butt would have degraded within a few days, the sheriff’s office said investigators determined Schlobom had been near Mattson when she was killed. However, officials didn’t have any other evidence to prove that he was in the park when Mattson died.

Nearly a decade later, in November 2019, investigators interrogated Schlobom, who is currently serving life in prison in Arizona without the possibility of parole for a 2005 murder. He reportedly "refused to answer any questions and demanded to be returned to his prison cell." Detectives discovered he was in bad health and used a wheelchair at the time.

In April 2021, Schlobom reportedly wrote a letter to detectives, disclosing that he had information about Mattson’s death. The sheriff’s office said he asked for a "long list of demands" to provide the details. Island County Prosecutor Greg Banks said, "Of all his crazy demands, the only one I considered was to allow him to spend the rest of his life in a Washington prison if he turned out to be the murderer and pleaded guilty."

When investigators interviewed Schlobom again in June 2021, he reportedly answered all of their questions. The sheriff’s office said Banks and detectives "left the interview confident that they had found” the victim’s killer. One of the detectives stated, “He knew things that only the killer and detectives knew," and Schlobom "filled in gaps and explained his motive: He killed her over a dispute about a drug deal."

According to the sheriff’s office, Schlobom agreed to sign a confession if he was transferred to the Washington Department of Corrections. This would have led to charges of first-degree murder and first-degree kidnapping. However, the deal didn’t go through.

Authorities said, "Under standard interstate protocols, a convicted inmate brought from State A to be prosecuted for charges in State B would have to return to State A after the trial and serve the original sentence in State A before being sent back to State B." Schlobom wouldn’t sign the confession without a guarantee that he could stay in Washington. With the height of the pandemic, Washington’s prison system was also not likely to take Schlobom due to his severe medical issues.

Banks continued to try to negotiate with Schlobom. In October 2024, one of Schlobom’s family members contact Banks and said the suspect had suffered "a series of debilitating strokes and had advanced dementia," and "she doubted Schlobom could read or understand the content of the letters." Due to his mental condition, Schlobom can’t be prosecuted.

According to the sheriff’s office, Banks and investigators suspect Schlobom acted alone when he killed Mattson. Banks described Schlobom as being "cold, matter-of-fact, and forthcoming about the crime" during their past interview with him. The prosecutor added, "We’re always wary when talking with a suspect who is trying to get a deal from us, but in this case, everything he said was consistent with what we knew, and was information that nobody else could have known. His memory was quite good at the time."

Although Schlobom won’t be officially charged in the victim’s death, Banks said he and detectives "were able to give some measure of closure to Tammy’s family. They know who is responsible and that he will spend the rest of his life in prison."

According to Island County Sheriff Rick Felici, a "personal beef" between Schlobom and Mattson led to the killing. On Jan. 9, the sheriff said the investigation is considered complete and closed.

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