Gaff, 68, a convicted rapist, ended up confessing to opening the murders of Judy Weaver and Susan Vesey, which occurred in 1980 and 1984
Susan Logothetti and two colleagues stood in front of the yellow house in Everett, Washington, dressed in T-shirts and holding flyers promoting a chewing gum company. Mitchell Gaff opened the door wearing pajama bottoms, welcomed the trio into his home and agreed to do a test, enthusiastically trying different tablets, Logothetti recalls of the January 2024 meeting.
When it was time for Gaff to try a new flavor, a colleague handed him a small plate. “I remember seeing him spit the first piece of candy onto the plate and seeing the saliva, and it was very difficult for me to contain my excitement,” Logothetti tells CNN.
Unknowingly, Gaff had provided three undercover detectives with the DNA they needed to confirm his link to a rape and murder case that occurred in 1984, according to a probable cause affidavit filed in March. The “gum trick” is mentioned in the statement.
Gaff, 68, a convicted rapist, confessed on April 16 to the murder of Judy Weaver as well as the murder of Susan Vesey, which occurred four years earlier, according to court documents. Now, a judge has sentenced Gaff to a sentence that could range from 50 years in prison to life in prison, according to a statement from Everett police.
Investigations into the homicides of the two Washington state women in 1980 and 1984 – at the time considered unrelated – had led to suspects in each case, but not charges. Until, four decades after Weaver’s murder, forensic experts discovered that the DNA extracted from the chewing gum was compatible with the evidence found on the victim’s body. This discovery, and the possible link between the two homicides, represented a decisive step forward in the investigations and demonstrated how crucial modern DNA analysis technology is in solving cold cases.
Furthermore, identifying the killer also allowed families who had lived for so long under the dark cloud of suspicion to heal and brought some relief to a woman Gaff attacked before the murders.
For the case to finally be closed, Weaver and Vesey’s cases “just needed science to advance,” Logothetti concludes.
DNA profiling helped capture the killer
Mitchell Gaff was “randomly trying to open doors and discovered that Susan Vesey’s door was unlocked” and then proceeded to tie up, beat, rape and strangle the victim, he admitted in his guilty plea. Four years later, Gaff attacked Judy Weaver, a 42-year-old mother, in her bedroom, which he then set on fire in an apparent attempt to destroy evidence, according to the affidavit.
“Before leaving, I wrapped ropes around her neck and set fire to a corner of the quilt, in an attempt to cover up my crime and with the intention of killing her,” admitted Gaff. “Judy Weaver died because of my actions.”
Gaff stated in his statement that he did not know any of the women before the first attacks. Heather Wolfenbarger, Gaff’s defense attorney, declined to comment.
At the time of the homicides, DNA analysis. In Weaver’s case, however, authorities “had the foresight” to contact the laboratory to obtain vaginal swabs, which led them to present the evidence within hours of her death, according to court documents.
The Weaver homicide case, which Logothetti ultimately inherited from his predecessors at the Everett Police Department, was rife with bizarre theories surrounding his death, involving money laundering and cocaine. Weaver’s boyfriend at the time of the homicide died in 1994 as the prime suspect in the case.
The emergence of DNA profiling ultimately led authorities to reopen Weaver’s 2020 homicide case.
Lisa Collins, a forensic specialist with the Washington State Police, explains to CNN that new software and DNA technology are two relatively recent milestones in DNA technology that have enabled advances in cold cases like these.
Collins, who took on Weaver’s case in 2003, says forensic experts can use newly developed software called to identify a profile from smaller amounts of DNA, in other words, “do more with less.”
In Weaver’s case, for example, one of the samples found on her body contained a lot of Weaver’s own DNA, some from her boyfriend and a much smaller amount from an unknown third person, Collins says. Forensic scientist Mary Knowlton used STRmix to subtract Weaver and her boyfriend’s DNA from the sample and narrow the analysis to the mystery contributor.
Knowlton then entered that DNA profile into the Combined DNA Index System known as CODIS – a national database that includes, among others, profiles of convicted criminals across the country – in November 2023 and found a match with Mitchell Gaff.
Gaff was on the database because of the violent rapes of two teenage sisters in his Everett, Wash., home just under three months after Weaver’s homicide, according to the probable cause affidavit.
“I didn’t expect this to come to anything, since in the 1980s people weren’t taking as many precautions when it came to DNA,” says Mary Knowlton. “So I was hoping it would be some unknown profile of an emergency medical technician or something. But you nailed it, and that was extremely exciting.”
After Knowlton found the match, detectives needed another DNA sample to confirm it. Susan Logothetti explains that detectives often track down suspects and collect cigarette butts or leftover drinks to obtain this secondary sample. Police watched Gaff’s house for a while, but he hardly left except to go to a nearby grocery store.
It was then that one of the agents came up with the idea for the gum ploy, “which I thought was a little crazy at the time,” admits Logothetti, who “had never participated in anything so elaborate.”
The DNA extracted from Gaff’s chewing gum was consistent with that found on Weaver’s vaginal swabs, on her neck and wrist restraints and on articles of clothing cut from her body, according to court documents.
Linking Gaff to Vesey’s murder would take longer. A few months after Knowlton linked Gaff’s DNA to Weaver’s murder, Vesey’s husband, Ken, left a voicemail with police to inform them that his brother, once a suspect in his wife’s murder case, had passed away.
Ken was 23 when he found his wife’s body on the bedroom floor, with their 15-week-old baby in the bed next to her, unharmed.
Logothetti, who took over the cold homicide investigations in 2022, had never heard of Susan Vesey’s case. He called Ken back and asked him to describe his wife’s murder. As he spoke, the detective noticed “striking similarities” between the cases. “The only thing I could think about was Judy Weaver,” Logothetti says.
The agent sent several objects collected from the scene of Vesey’s homicide for analysis. A piece of white cord cut from the victim’s body confirmed: the DNA was Gaff’s.
“What seems relevant to me is how sophisticated forensic scientists have become and how sophisticated the DNA technology is that allows scientists to do what they do,” says Craig Matheson, prosecutor in the Gaff case. “What they can do now, compared to what they could or couldn’t do 20 years ago, is very significant.”
A “sexual sadist” living in freedom
In November 1979, Mitchell Gaff had attacked and attempted to rape Jacalyn O’Brien, 29, in her garage, a crime for which he was sentenced to five years probation and one year open labor.
Gaff killed Vesey in the months before his conviction and was on parole when he raped his two teenage sisters in August 1984 – brutal attacks for which O’Brien, now 76, still feels “horrible, horrible guilt”. He was convicted of the attacks in February 1985, sentenced to 11.5 years and released from prison in October 1994, according to court records.
Jacalyn O’Brien tells CNN that she has watched Gaff’s trials and hearings from a distance since he attacked her decades ago, but that she felt “ashamed” about not attending in person. Last month, when he pleaded guilty, she did.
“The reason I didn’t go to court is because I refuse to let that son of a bitch see me crying, and it’s been almost 50 years, and I feel like just talking about it makes me start to cry right now,” says O’Brien. “So I didn’t want him to be able to see it, but I felt like this last time, I had to be a bigger person and show up.”
Jacalyn O’Brien, then a trooper with the Washington State Police, was putting away her lawn mower in her garage in North Everett when Gaff approached her with a gun — which later turned out to be a BB gun — and told her to get down on her knees and “not turn around,” she says. Instinctively, she turned to face him. “I remember standing there, smiling, thinking it was one of my friends from the state police playing a prank on me… and then he hit me in the head with the gun,” she recalls.
When Gaff dropped the gun to tie one of her wrists, Jacalyn thought of her father, who always taught her how to defend herself. He threw his body weight at him, which threw him against the wall and seemed to catch him off guard. They both got up. He had her cornered. Gaff took a hunting knife from his boot. O’Brien raised his hands and began to apologize, and he slashed his outstretched palm.
“He said, ‘I’m going to kill you now, you bitch’…so I knew I was dead, so I thought, ‘Here we go,’” O’Brien recalls.
He pushed Gaff, hitting him and scratching his neck. O’Brien managed to escape to a nearby alley, where neighbors caught her and called the police.
Mitchell Gaff admitted to a mental health expert in 1994 that he intended to rape O’Brien. The expert, as other experts had done before, diagnosed Gaff as a “sexual sadist.”
To this day, Jacalyn O’Brien says she can’t keep the television or radio on at home because she needs to be able to “hear every little noise.”
“I really regret not being able to kill him the day he attacked me,” he says.
From the time Susan Logothetti answered Ken Vesey’s call until the day he passed away last year, the two talked on the phone once a week — sometimes about the case, sometimes about their own lives. Logothetti says confirming Gaff’s connection to the case allowed healing to begin within the family.
“I’m just happy that the families finally know the truth, because it’s like cancer in the family that spreads,” says the detective. “Mitchell Gaff claimed more victims than just these women. Families are victims too.”
