Two detectives pulled up to a house in Olympia, Washington in 2024, knocked on the door, and introduced themselves as representatives of the chewing gum industry. They were dressed casually — short shorts, tight T-shirts — calculated to seem unthreatening, unofficial, ordinary. They had a survey. They had free samples. They had small lidded cups for the discarded pieces.
The man who answered the door was Mitchell Gaff, 68, a registered level-three sex offender living under the legally changed name Sam Price. He agreed to participate. He tried several flavors. He spat each piece into the cups the women provided. He had no idea he had just handed investigators the last piece of evidence needed to charge him with two murders he had committed more than four decades earlier.
On April 16, 2026, Gaff stood in a packed Snohomish County Superior Court and pleaded guilty to two counts of first-degree murder with premeditated intent — the 1984 killing of Judith “Judy” Weaver and the 1980 killing of Susan Vesey, both women strangers to him, both attacked in their own homes in Everett, both bound, raped, and strangled while their children slept or waited nearby. He read aloud, without visible emotion, detailed statements describing how he killed each woman. He is scheduled to be sentenced on May 13.
Two Women, Two Decades, One Predator
The case begins not in a courtroom but in the domestic ordinariness of two lives abruptly ended.
Susan Vesey was 21 years old — it was the morning after her birthday — when her husband Ken returned home from a night shift on July 12, 1980, and found her murdered inside their Casino Road home in Everett. Their two-year-old daughter and infant son were in the residence, unharmed. Vesey had gone downstairs to lock the front door. She never came back up.
Four years later and less than two miles away, Judy Weaver, 42, was finishing a long shift as bar manager at the Bell-Ness Cafe on June 1, 1984. She had been working since 6 a.m. By 9:30 p.m. she was too tired to drive and asked the bartender to call her a cab. When the taxi hadn’t arrived twenty minutes later, she decided to walk the short distance home to her Rucker Avenue apartment. On the way, she stopped at a Dairy Queen for ice cream. A witness recalled seeing her there with a young man. It was the last confirmed sighting of Judy Weaver alive.
Shortly after midnight, a pedestrian on Rucker Avenue noticed smoke billowing from her apartment window. Firefighters forced entry through the back and found the fire contained to the bedroom. Weaver was inside. Ligatures — drawstrings and telephone extension cords — were around her throat. Gaff, then 26, had removed the batteries from her smoke detector before setting fire to the bedspread.
Two mothers. Two homes turned into crime scenes. Two cases filed, investigated, and stalled — then warehoused for decades as leads dried up and the technology to match the biological material left behind simply did not exist.
The Predator’s History: A Documented Record of Violence
Understanding the Gaff investigation requires understanding what was already known about him long before the cold case charges. His documented history of violence against women is among the most extensive in Washington State criminal records.
His first known offense dates to the day before Thanksgiving, 1979 — one year before he killed Susan Vesey. He approached Jackie Brown, then 29, as she was putting her lawnmower away in her tool shed in Everett. He brandished what appeared to be a handgun — it was an air pistol — forced her to her knees, and beat her repeatedly in the head, slamming her skull against the cement floor. Brown survived only by waiting until he set the weapon down and throwing herself against him, catching him off guard. She told investigators he had said, calmly, “You’re going to die now.” She ran. He fled.
In 1984, the same year he killed Judy Weaver, Gaff broke into the home of two teenage sisters in Everett. Court documents detail how he tied both girls with an electrical cord, cut off their clothing, and repeatedly raped them. One girl escaped and ran for help. Gaff fled but was identified and convicted — sentenced in 1985 on two counts of rape and burglary. His DNA profile entered the federal CODIS database as a consequence of that conviction.
In subsequent Sexually Violent Predator proceedings in 1994 and 2000, juries twice found Gaff met the legal standard for civil confinement. During those trials, he made admissions that prosecutors would later cite as evidence of his broader predatory behavior: at one point in the 1980s, he claimed he had been attempting to attack as many as 30 women in a single day, and acknowledged sexually assaulting at least eight of them. He was, in the clinical language of forensic psychology, not a man who committed violence episodically. He committed it systematically, as close to an occupation as anything else in his life.
The Forensic Breakthrough: CODIS Reaches Back Forty Years
In 2020, Everett investigators reopened the Judy Weaver case with a specific purpose: reanalysis of the biological material collected at the crime scene in 1984 using DNA technology that had not existed when the evidence was first processed.
The key physical evidence was the ligatures — the drawstrings and telephone cords used to bind Weaver — which had been preserved in the evidence archive. Modern short tandem repeat analysis and probabilistic genotyping can now extract usable DNA profiles from contact trace evidence: material transferred from an offender’s hands to a surface through touch alone, even decades earlier, even in tiny quantities.
Three years after the reinvestigation began, in 2023, the crime lab returned a result. The DNA extracted from the wrist ligatures was a match in CODIS to a profile already on file: Mitchell Gaff, entered into the database following his 1985 rape conviction.
It was the link investigators had been building toward. But they faced a problem familiar to cold case prosecutors: a CODIS match is a powerful indicator, not by itself a sufficient basis for a watertight prosecution. Defense attorneys routinely challenge the integrity of decades-old evidence storage, the chain of custody for biological samples, and the statistical weight of a match. Investigators wanted a fresh, uncontested, direct sample of Gaff’s DNA — something collected without any possibility of cross-contamination, mishandling, or legal challenge.
The Sting: Fieldcraft in a Cold Case Investigation
What the Everett Police Department did next was tactically inventive and legally defensible: they ran a covert operation to obtain Gaff’s DNA voluntarily, without his knowledge of the investigation’s purpose, and without any search warrant being required.
Two female detectives drove to Gaff’s residence in Olympia — where he was living under the name Sam Price, his legally changed identity — and presented themselves as researchers conducting consumer surveys on behalf of the gum industry. Their choice of clothing was deliberate: casual, non-threatening, nothing that read as law enforcement. They offered Gaff free samples of various flavors and asked him to taste-test them. He obliged. Each discarded piece went into a small lidded collection cup.
The legal framework here is established precedent. In the United States, a person has no Fourth Amendment expectation of privacy in material they voluntarily discard. A discarded coffee cup, a cigarette butt, a piece of chewing gum — once abandoned, the biological material it carries is lawfully retrievable without a warrant. Courts have consistently upheld covert DNA collection from discarded items in public and semi-public spaces. The ruse itself — the false pretext — raises no independent constitutional issue, because no coercion was involved. Gaff chose to participate. He chose to discard the gum. The choice was his.
The gum was sent to a laboratory for DNA extraction and comparison. The result confirmed what the CODIS match had already suggested: the DNA from Gaff’s saliva was consistent with the vaginal swabs and the neck ligature recovered from Judy Weaver’s body. He was arrested in May 2024.
The Courtroom: A Killer Reads His Own Confession
The plea proceeding on April 16, 2026, was extraordinary in its detail. As part of the agreement, Gaff was required to read aloud, in open court, written statements describing how he killed both women. He sat between his two defense attorneys and read without visible affect.
In describing the Weaver killing, he acknowledged he had gone out that night “looking to rape women or burglarize them.” He described waiting outside her building — going back and forth between the front door and the back — until she began to open the rear entrance. He kicked the door hard enough to knock her to the floor. He described the binding, the rape, the fire he set afterward to destroy evidence. He had been drunk and high at the time. The statement ended: “Miss Weaver died because of my actions.”
For the Vesey killing, he described trying random doors in Everett until he found one unlocked. He entered, hid in the kitchen, and when Vesey came downstairs to lock the front door, he moved to conceal himself in her bedroom closet. When she entered the bedroom, he grabbed her from behind.
Both women, he said, were strangers to him. He had arrived at both homes without weapons, taking knives from their kitchens once inside.
The courtroom was packed. Prosecutor Craig Matheson, speaking after the hearing, described the plea as the right outcome for the families. The DNA evidence in both cases, he said, was Gaff’s profile on the ligatures used to bind and strangle the women — material he called “pretty damning.”
Forensic Analysis: The Architecture of the Investigation
The Gaff prosecution demonstrates a sophisticated layering of forensic methods across a multi-decade investigation, each phase enabled by technologies unavailable to the investigators who came before.
Phase One — Original Investigation (1980, 1984). Biological evidence was collected at both scenes, including vaginal swabs and ligature material. The DNA profiling techniques needed to generate a searchable genetic profile from such samples would not exist for another decade. The evidence was preserved but unusable.
Phase Two — CODIS Entry (1985). Gaff’s conviction for the rape of the teenage sisters resulted in his DNA being entered into the Combined DNA Index System. This created the latent connection between his profile and the archived crime scene material — a connection that could not yet be made.
Phase Three — Cold Case Reinvestigation (2020–2023). Advances in touch DNA analysis and probabilistic genotyping allowed investigators to generate a usable profile from the degraded ligature evidence. When submitted to CODIS, it returned Gaff’s name. The match covered both the Weaver scene material and, subsequently, evidence from the Vesey scene.
Phase Four — Covert Sample Collection (2024). To obtain legally unimpeachable confirmatory DNA, detectives ran the gum industry ruse. The fresh saliva sample, compared against both crime scene profiles, provided the prosecution-ready direct evidence.
Phase Five — Arrest, Charge, Plea (2024–2026). Gaff was charged first in the Weaver case in May 2024, then in the Vesey case in March 2026. The guilty plea on April 16 resolved both matters simultaneously.
The OSINT dimension of the investigation is also notable. Locating Gaff required investigators to trace a subject living under a legally changed name in a different city — a challenge that involved cross-referencing sex offender registry data, property records, and possibly vehicle registration, all legally accessible public records that modern investigators mine routinely as part of cold case subject-location efforts.
Criminal Psychology: The Organized Serial Predator
The behavioral profile that emerges from the documented record is consistent with what forensic psychologists classify as an organized sexual predator — a category defined by planning, target selection, and the operational management of risk. Gaff did not commit opportunistic violence. He went out, by his own admission, with a specific purpose: to find and assault women. The variety of his approaches — waiting outside a bar manager’s apartment, trying random door handles in a residential neighborhood — reflects flexible tactical thinking in service of a fixed predatory goal.
The fire he set in Weaver’s bedroom is forensically significant. It is a deliberate evidence-destruction behavior, not an expression of rage or a secondary crime of opportunity. It indicates a perpetrator who was aware, even in the immediate aftermath of the killing, that physical evidence constituted a risk. That awareness — present in a 26-year-old in 1984 — suggests prior experience managing the aftermath of violent crime, which the timeline of his offending confirms.
The clinical designation “sexual sadist” — applied through formal psychological evaluation in the Sexually Violent Predator proceedings — places Gaff within a small but extensively studied subset of violent offenders for whom sexual gratification is intertwined with the infliction of suffering or terror. This is not a colloquial description but a DSM-defined diagnosis, arrived at through structured professional assessment. It carries significant weight in both the civil confinement proceedings that kept him locked up through the 1990s and in the current sentencing context.
His decision to plead guilty — rather than proceeding to the September 2026 trial date — is likely a function of evidence assessment rather than remorse. The DNA evidence connecting him to both ligature sets was, in the prosecutor’s own framing, overwhelming. A plea avoids the reputational spectacle of a full trial and may have involved negotiated terms on the sentence structure, though those details have not been made public.
Law Enforcement Challenges: The Legal Tightrope of Covert DNA
The gum sting will become a case study in law enforcement training programs. It solved two murders. It also navigated a genuine legal tightrope.
Covert DNA collection from discarded material is lawful under current Fourth Amendment jurisprudence — but the underlying deception creates ethical and strategic risk. Had Gaff’s attorneys successfully argued that the ruse constituted a form of custodial interrogation or that the detectives misrepresented their purpose in a way that vitiated the voluntary nature of his participation, the fresh DNA evidence might have faced suppression challenges. The collection cups with lids — preserving the gum in a sealed environment — were a careful evidentiary precaution, reducing contamination arguments.
More broadly, the case illustrates the growing practice of undercover DNA collection as a tool in cold case investigation. Law enforcement agencies across the United States and Europe have used similar approaches: posing as utility workers, survey researchers, or delivery personnel to obtain biological material from suspects under surveillance. The technique bypasses the warrant requirement while generating fresh, uncontested evidence. Its legality is settled; its ethics remain debated.
Global Context: Chewing Gum, Cigarettes, and the End of Biological Anonymity
The Mitchell Gaff investigation belongs to a wave of cold case closures driven by the convergence of legacy crime scene evidence, expanded DNA databases, and increasingly sensitive laboratory techniques. What is new, and what this case exemplifies more vividly than most, is the operational creativity now applied to obtaining confirmatory samples.
In the United Kingdom, investigators in multiple cold cases have retrieved DNA from discarded coffee cups and cigarette butts left by suspects placed under surveillance. In Australia, a 1994 murder was resolved in 2021 using DNA from a water bottle a suspect had thrown away during a police interview. Germany’s Bundeskriminalamt has formalized covert DNA collection protocols as a standard investigative tool.
The underlying principle is the same across jurisdictions: the body does not lie, and it cannot keep its secrets if it keeps shedding them. Every surface a person touches, every object they place in their mouth, becomes a potential source of the genetic profile that is uniquely theirs and permanently on record once they enter a criminal database.
For Gaff, the irony is precise. He was a man who had spent decades managing his identity — changing his name legally, relocating across the state, registering under a new designation. He had constructed, with some care, a life that placed distance between Sam Price in Olympia and Mitchell Gaff in Everett in 1980 and 1984. What he could not manage was his saliva. What he could not anticipate was that two women in casual clothing on his doorstep were not selling anything. They were collecting.
Conclusion
Judy Weaver was 42, a bar manager who took a late-night walk home and stopped for ice cream. Susan Vesey was 21, home with her two small children the morning after her birthday. Neither woman had any connection to the man who killed them. They were chosen because they were accessible. They were killed because he could.
For forty-six years in Vesey’s case and forty-two in Weaver’s, Mitchell Gaff lived with what he had done. He was convicted of rape, assessed as a sexually violent predator, confined and released, and ultimately settled into a quiet life in a different city under a different name. He answered the door when two strangers knocked. He tried the gum. He threw the pieces away.
Sentencing is scheduled for May 13. Given his age, his diagnosis, and the nature of the crimes, prosecutor Craig Matheson noted that the plea agreement will in all likelihood mean Gaff dies behind bars. For the families of Judy Weaver and Susan Vesey, that is the only geography that matters now.
ForensicTimes · forensictimes.com · Investigative Journalism on Crime, Justice & Forensic Science © 2026 ForensicTimes. All rights reserved. Published May 1, 2026.
