How discarded chewing gum helped convict a serial rapist of two cold case murders
A Simple Act of Spitting Led to a Major Breakthrough
How discarded chewing gum helped convict – Susan Logothetti and two colleagues had just arrived at a modest yellow house in Everett, Washington, on a chilly January day in 2024. Dressed in casual attire and clutching promotional flyers for a chewing gum brand, they were greeted by Mitchell Gaff, who wore pajamas and invited them inside. The encounter, which began as a routine outreach, took an unexpected turn when Gaff eagerly sampled the gum, spitting the first piece into a small dish. This seemingly mundane action would later become the pivotal clue in solving two decades-old murders.
“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,” Logothetti recounted to CNN. Her words captured the moment when a casual interaction transformed into a forensic revelation.
The DNA collected from the gum was instrumental in linking Gaff to the 1984 rape and murder of Judy Weaver. According to an affidavit of probable cause filed in March, the “gum ruse” served as the key evidence that finally connected him to the crime. Gaff, 68, had already been convicted of sexual assault, but the DNA from the saliva provided the conclusive proof needed for his admission of guilt in the murders of Weaver and Susan Vesey.
A Conviction Born from Cold Case Persistence
Gaff’s guilty plea, submitted on April 16, detailed the violent acts he confessed to committing against both women. In the 1980 case, Vesey, a 21-year-old mother of two toddlers, was found dead in her bedroom. Gaff described how he had “tried random doors” and discovered her door unlocked, proceeding to tie her up, beat her, and strangle her. He also admitted to attacking Weaver four years later in her home, setting fire to the room to obliterate evidence. “Ms. Weaver died because of my actions,” he stated in the plea.
The murders had initially been considered separate incidents, with no clear connection between the victims or the suspects. For decades, investigators struggled to pinpoint the perpetrator, leaving families in uncertainty. The breakthrough came when forensic scientists analyzed the DNA from Gaff’s saliva, which matched evidence found on Weaver’s body. This confirmation not only solved the 1984 case but also linked it to the 1980 murder, revealing a pattern of violence that had eluded authorities for years.
Technological Advances Reveal the Truth
Four decades after Weaver’s murder, modern DNA technology finally provided the answers that had once seemed out of reach. At the time of the crimes, DNA profiling was still a nascent tool, and many cases were left unsolved due to limited capabilities. However, the foresight of law enforcement in collecting vaginal swabs from Weaver’s body proved vital. The evidence was submitted to the lab just hours after her death, setting the stage for future advancements.
Logothetti, who inherited the case file from previous investigators, noted that the original theories surrounding Weaver’s death were as varied as they were bizarre. The file included speculations about money laundering and cocaine use, with Weaver’s boyfriend being the primary suspect. He died in 1994, but his involvement in the case was ultimately overshadowed by the new DNA evidence. “The cases just needed science to catch up,” Logothetti said, highlighting the role of technology in bridging the gap between past crimes and present-day justice.
From Evidence to Identification: The Power of Genetic Analysis
Forensic scientists at Washington State Patrol have since emphasized how modern techniques like STRmix have revolutionized cold case investigations. This software enables the extraction of DNA profiles from small, mixed samples, allowing for more precise identifications. In Weaver’s case, a binding from her body contained DNA from herself, her boyfriend, and an unknown third person. Using STRmix, the team isolated the third contributor’s profile, which was then matched against national databases.
Mary Knowlton, a forensic scientist who worked on the case, explained the process in detail. “We plugged that DNA profile into CODIS, the Combined DNA Index System, and found a match with Mitchell Gaff,” she said. The system, which houses profiles of convicted offenders, became the final piece of the puzzle. This match not only confirmed Gaff’s guilt but also validated the theory that he was a serial offender, targeting women in isolated settings.
Impact Beyond the Courtroom: Healing for Families
The identification of Gaff has brought a sense of closure to the families of Vesey and Weaver, who had lived under the weight of unanswered questions for over 40 years. For Vesey’s relatives, the conviction has provided a rare opportunity to confront the past and find peace. Similarly, the survivors of Gaff’s earlier attacks have found solace in the justice delivered through the gum sample.
Heather Wolfenbarger, Gaff’s defense attorney, declined to comment on the case. Despite the evidence, she likely focused on the legal implications of the conviction, which now hangs over Gaff as he prepares for sentencing on Wednesday. The maximum penalty he faces is life in prison, a fate that underscores the severity of his crimes.
The story of Mitchell Gaff’s conviction illustrates the transformative potential of forensic science in cold cases. What began as a simple interaction with a chewing gum company has now become a landmark example of how modern DNA technology can uncover truths buried in time. The spitting of a single piece of gum into a ramekin, a moment that seemed insignificant at the time, has since become the cornerstone of a major breakthrough in criminal justice.
Logothetti’s experience highlights the importance of persistence and adaptability in law enforcement. While early investigations had pursued various leads, the lack of DNA evidence left them in a state of uncertainty. The advent of genetic genealogy and advanced software like STRmix has since opened new avenues for solving such cases, proving that even the most elusive crimes can be unraveled with the right tools.
Gaff’s admission of guilt, coupled with the DNA evidence, has not only solved two cold cases but also exposed a pattern of violence. His attacks on Vesey and Weaver, followed by attempts to destroy evidence, demonstrate a calculated mindset. The combination of physical assault and arson suggests a desire to erase his crimes from the public record. Yet, the DNA sample from the gum has outlasted his efforts, serving as a silent witness to the events of 1980 and 1984.
As the case moves toward its conclusion, the role of the gum sample remains central. It underscores how everyday objects can hold the power to unlock the secrets of the past. The perseverance of detectives, the ingenuity of forensic scientists, and the relentless march of technology have all contributed to this moment of justice. For the victims’ families, the resolution of these cases offers more than just a legal verdict—it provides a chance to heal and rebuild their lives after years of uncertainty and grief.
