A 68-year-old convicted serial rapist will spend the rest of his life behind bars after admitting he raped and killed two women in Everett, Washington, in the early 1980s, crimes that went unsolved for more than four decades until three undercover detectives showed up at his door pretending to promote chewing gum.
A judge on Wednesday sentenced Mitchell Gaff to a minimum of 50 years and a maximum of life in prison for the murders of Susan Vesey, a 21-year-old mother of two, and Judy Weaver, a 42-year-old mother, CNN reported, citing court documents and an Everett Police Department news release. Gaff admitted on April 16 that he killed both women, strangers to him, in separate attacks years apart.
The break came from a piece of spit-out gum. And behind it lay decades of work by forensic scientists, a detective who refused to let two cold cases gather dust, and DNA technology that finally caught up to a predator the justice system had already caught, and released.
The 'gum ruse' that ended a 40-year hunt
In January 2024, Detective Susan Logothetti and two colleagues stood outside Gaff's yellow house in Everett wearing T-shirts and holding flyers for a chewing gum company. It was a lie. They were undercover, and the flyers were props.
Gaff opened the door in pajama pants and welcomed them inside. He agreed to a taste test. He sampled the gum. Then he spit it into a small ramekin.
Logothetti, who took over cold case homicide investigations for the Everett Police Department in 2022, told CNN she could barely contain herself. "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," she said. She called the encounter something she had "never been a part of anything this elaborate."
The encounter had been months in the making. Detectives had surveilled Gaff's house for a while, Logothetti said, but the man rarely left, venturing out only to a nearby grocery store. The elaborate cover story was their best shot at getting his DNA without tipping him off.
It worked. Four decades after Weaver's death, forensic scientists found that DNA extracted from the gum was consistent with evidence found on her body, court documents stated. The match extended to DNA found in Weaver's vaginal swabs, on ties from her neck and wrists, and on clothing cut from her body.
A trail of violence that started in 1979
Gaff's known history of sexual violence stretches back to November 1979, when he attacked Jacalyn O'Brien, then a 29-year-old Washington State Patrol officer, in her garage in North Everett. O'Brien, now 76, described the assault to CNN in detail that remains vivid nearly half a century later.
"I can remember standing there smiling and thinking it was one of my state patrol trooper friends playing a joke on me... and then he whacked me across the head with this gun," she said. O'Brien escaped into a nearby alley, where neighbors picked her up and called police.
Gaff's punishment for that attack: five years of probation and one year of work release, according to Logothetti and prosecuting attorney Craig Matheson. Probation and work release for a violent sexual assault on a law enforcement officer. That sentence, or lack of one, is worth sitting with.
Eight months later, in July 1980, Susan Vesey was dead. The young mother was attacked in her apartment. Gaff admitted in his guilty plea that he had been "trying random doors and found the victim's door unlocked." He tied her up, beat her, raped her, and strangled her. Her husband, Ken Vesey, found her body. He was 23. Their baby, just 15 weeks old, was on the bed next to her, unharmed.
The case of Rex Heuermann, the Long Island architect who pleaded guilty to killing eight women in the Gilgo Beach serial murder case, has reminded the country how long serial predators can evade justice. Gaff's timeline tells a similar story of escalation and institutional failure.
Four years after Vesey's murder, in June 1984, Gaff struck again. Judy Weaver, 42, was attacked in her bedroom. In his guilty plea statement, Gaff admitted what he did next:
"Before leaving I wrapped cords around her neck and lit the corner of the bedspread in an attempt to cover up my crime and with the intention of killing her. Ms. Weaver died because of my actions."
Just under three months after Weaver's killing, in August 1984, Gaff raped two teenage sisters in their Everett home. He was convicted in February 1985 and sentenced to 11.5 years. He was released from custody in October 1994.
During that incarceration, Gaff admitted to a mental health expert in 1994 that he had intended to rape O'Brien. The expert, like others before, diagnosed Gaff as a "sexual sadist," the affidavit of probable cause stated. And yet the system let him walk out.
Science catches up
For years, the Weaver case pointed at the wrong man. Weaver's boyfriend at the time of her death was the main suspect until he died in 1994, Logothetti said. But investigators in Weaver's case had done one thing right from the start: law enforcement "had the foresight" to call the lab about obtaining vaginal swabs, which led them to submit evidence just hours after her death, court documents stated.
That preserved evidence sat waiting for science to catch up. And it did, slowly. Forensic scientist Lisa Collins at the Washington State Patrol picked up Weaver's case in 2003. Collins told CNN that new software and advances in genetic genealogy had enabled breakthroughs in cold cases, allowing scientists to "do more with less."
Other cold cases across the country have followed a similar arc. A North Carolina man was recently charged with first-degree murder in a 1990 New Jersey cold case after a DNA breakthrough, one of a growing number of decades-old killings cracked by forensic technology that did not exist when the crimes occurred.
The real turning point in Gaff's case came in 2020, when law enforcement revisited Weaver's death. Forensic scientist Mary Knowlton used STRmix software to subtract Weaver's and her boyfriend's DNA from a sample and isolate an unknown contributor. In November 2023, Knowlton plugged that profile into CODIS, the national database of convicted offender DNA profiles, and got a hit: Mitchell Gaff.
Knowlton told CNN she hadn't expected a result.
"I wasn't expecting anything to come from this, being the '80s, not as many DNA precautions are taken. So I was expecting this to be some unknown profile from an EMT responder or something like that. But it did hit, and that was extremely exciting."
Gaff was already in CODIS because of his 1985 conviction for the rapes of the two teenage sisters. His DNA had been sitting in a federal database for years, waiting for someone to ask the right question with the right tools.
Two cases become one
The connection between the Weaver and Vesey cases came through a phone call that was almost accidental. A few months after Knowlton matched Gaff's DNA to the Weaver evidence, Ken Vesey, Susan's husband, left police a voicemail. He called to say his brother, once a suspect in Susan's case, had died.
Logothetti called him back. As Ken Vesey described the circumstances of his wife's murder, Logothetti noticed striking links to the Weaver case, "which I thought was kind of crazy at the time," she said. She sent items from the Vesey crime scene for testing. A piece of white cord cut from Susan Vesey's body confirmed the DNA was Gaff's, the affidavit stated.
Logothetti spoke with Ken Vesey weekly after that. He died last year, before the case reached its conclusion. The detective's words about the toll were plain: "Mitchell Gaff made more victims than just these women. It's all of the families."
Cases like these, where a family's refusal to quit keeps a cold case alive for decades, show that persistence matters as much as technology. Ken Vesey's call to police, decades after his wife's murder, helped tie two cases together.
A survivor's reckoning
Jacalyn O'Brien, the woman Gaff attacked in 1979, attended his guilty plea last month, in person, for the first time. She had followed his trials and hearings remotely for years, unwilling to let him see her react.
"The reason I haven't gone into court is because I refuse to let that S-O-B see me cry, and it's been almost 50 years, and I can tell I'm starting to cry right now. So I didn't want him to be able to see that, but I felt that this last one, I had to be a big girl and show up."
O'Brien described lasting effects from the attack. She still locks every door. She can "hear every little noise." She carries what she called "horrible, horrible guilt", the knowledge that after Gaff received probation for attacking her, he went on to kill.
"I'm very sorry that I wasn't able to kill him the day he attacked me," she said.
The case also underscores how forensic identification can bring answers even when decades-old evidence seems impossibly degraded. Prosecuting attorney Craig Matheson credited the scientists directly.
"The thing that seems relevant to me is just how sophisticated the forensic scientists have become, and how sophisticated the DNA technology is that allow the scientists to do what they do. The things they can do now compared to what they were able to do or not do 20 years ago is very significant."
A system that failed before science could save it
Gaff pleaded guilty in Snohomish County Superior Court to the rapes and murders of both women, Fox News reported. Everett Mayor Cassie Franklin said she was "so proud of our Everett Police Department for solving this murder case by utilizing advancements in DNA analysis techniques."
Pride in the detectives and forensic scientists is well earned. Logothetti, Collins, Knowlton, and the undercover team did extraordinary work. But the timeline demands a harder question: What might have been prevented if the system had treated Gaff's 1979 attack on a state patrol officer as the warning it plainly was?
Probation and work release for a violent sexual assault. Eight months later, a young mother was dead. Four years after that, another woman was dead. Three months later, two teenage girls were raped. A mental health expert diagnosed Gaff as a "sexual sadist." And in October 1994, the state released him.
Investigations that revisit long-dormant cases with fresh eyes are producing results across the country. But in Gaff's case, the tragedy is not just that it took 40 years to identify him. It's that the system had him in hand after his very first violent crime, and chose to let him go.
DNA technology solved these murders. But it was a revolving-door justice system that made them possible in the first place.
