How discarded chewing gum helped convict a serial rapist of two cold case murders

A Sticky Clue: Chewing Gum Unlocks Two Cold Case Murders in Washington

The Unlikely Setup That Led to a Breakthrough

How discarded chewing gum helped convict – Three officers from the Everett Police Department approached the modest yellow house in Everett, Washington, on a chilly January day in 2024. Dressed in casual attire and holding promotional flyers for a local gum brand, they engaged Mitchell Gaff in a friendly conversation. Gaff, a 68-year-old man with a history of convictions, greeted them in pajamas and eagerly participated in a taste test, showcasing his enthusiasm for the various flavors. The moment he spat the first piece of gum into a small dish, one of the officers noted the saliva left behind. “I remember watching him spit the first piece of gum into the ramekin and seeing the saliva, and it was very hard for me to contain my excitement,” Susan Logothetti, one of the officers, recounted to CNN.

From A Sample to A Verdict

What began as a routine encounter would soon become a pivotal moment in solving two long-unsolved murders. The gum spitting incident provided the crucial DNA evidence needed to link Gaff to the 1984 rape and murder. According to an affidavit of probable cause filed in March 2024, this “gum ruse” served as the key to unraveling the mystery. Gaff, who had already admitted to multiple sexual assaults, confessed to the killings of Judy Weaver and Susan Vesey during a court appearance on April 16. He faces life imprisonment at his sentencing on Wednesday, a result of the evidence that finally connected the two cold cases.

The Tragic Backstories of the Victims

More than four decades ago, two women in Washington state met violent ends under circumstances that initially baffled investigators. Judy Weaver, a 42-year-old mother, was attacked in her bedroom in 1984, with her killer allegedly setting fire to the room to conceal his crime. Susan Vesey, a 21-year-old mother of two infants, was murdered in July 1980 after being found by Gaff when he randomly tried her door. The accused, who admitted to tying up, beating, and strangling Vesey, claimed he had no prior relationship with either victim. “Ms. Weaver died because of my actions,” Gaff stated in his guilty plea statement, highlighting the grim reality of his crimes.

Science Catching Up with the Evidence

At the time of the murders, DNA profiling had not yet reached the level of sophistication needed to solve such cases. However, in Weaver’s case, law enforcement demonstrated foresight by sending vaginal swabs to the lab shortly after her death. These samples, once analyzed, provided a critical lead. It wasn’t until 2020 that forensic scientists revisited Weaver’s case, leveraging advancements in DNA technology to uncover new connections. The breakthrough came in 2023 when a forensic expert used STRmix, a groundbreaking software, to isolate the DNA of an unknown third person from evidence found on Weaver’s body.

A Connection That Changed Everything

The DNA profile derived from the gum sample became the missing piece in the puzzle. By comparing it to the national database CODIS, which houses profiles of convicted offenders, forensic scientist Mary Knowlton identified a match: Mitchell Gaff. This connection not only solved the 1984 murder but also linked it to Vesey’s 1980 case, which had been considered separate for years. The discovery marked a turning point, proving how modern forensic techniques can bridge gaps left by earlier methods. As Lisa Collins, a forensic scientist at Washington State Patrol, explained to CNN, “Recent innovations in genetic genealogy and software have transformed cold case investigations. We can now extract more information from smaller DNA samples, like those found on a piece of gum.”

The Emotional Toll of Uncertainty

For the families of the victims, the years of uncertainty had been a relentless burden. Judy Weaver’s boyfriend, who was the main suspect in her murder, died in 1994, leaving the case with even more questions. The file Logothetti inherited from her predecessors was filled with speculative theories, ranging from money laundering to cocaine use, all of which lacked solid evidence. The emotional impact on Vesey’s family was profound, as they endured the anguish of not knowing who had taken their daughter’s life. “The cases just needed science to catch up,” Logothetti reflected, underscoring the importance of the DNA evidence that finally brought closure.

The Legacy of a Simple Sample

Gaff’s confession and the DNA evidence from the gum sample have not only secured his conviction but also redefined the way cold cases are approached. The use of STRmix in Weaver’s case exemplifies how forensic science has evolved to handle smaller, more fragmented DNA samples. Collins noted that such software allows investigators to analyze DNA ratios more effectively, enabling them to pinpoint suspects even when only trace amounts are present. This method proved vital in separating Weaver’s DNA from that of her boyfriend and identifying the unknown contributor, which ultimately pointed to Gaff.

From Cold Cases to Confessions

While Gaff’s guilt was confirmed through scientific means, the process also highlighted the emotional journey of the victims’ families. For years, they lived with the weight of suspicion, never knowing the truth. The ability to resolve these cases has brought a sense of relief and healing, particularly to the family of a woman Gaff had attacked before the murders. His admissions, coupled with the DNA evidence, have provided a long-awaited sense of justice. As the story unfolds, it serves as a reminder of how seemingly insignificant details can lead to monumental revelations in criminal investigations.

The Future of Forensic Science

The case underscores the growing power of DNA technology in cold case resolution. With tools like STRmix and genetic genealogy, investigators can now connect disparate pieces of evidence across decades. The gum incident, once dismissed as a mundane encounter, has become a symbol of how innovation in science can outpace human error or oversight. Heather Wolfenbarger, Gaff’s defense attorney, chose not to comment on the specifics of the evidence, but the court documents reveal the strength of the case built on this unique discovery. As the sentencing approaches, the community of Everett will reflect on the role of a single, sticky clue in delivering justice to two women whose deaths had long been a mystery.

Today, the story of Mitchell Gaff and the chewing gum that helped convict him stands as a testament to the intersection of crime, science, and persistence. What once seemed like a random moment has now become a landmark in forensic history, proving that even the smallest evidence can hold the power to change lives forever.