Decades after the brutal murder of a teenager in northwest Washington that left detectives unable to find answers, modern forensic tests have helped identify her killer.
Tracy Whitney's body was found by a fisherman on August 28, 1988, in the Puyallup River near the city of Sumner. She was naked, and a subsequent autopsy confirmed Whitney's name, determining her cause of death as asphyxiation and possibly strangulation. She was believed to have been sexually assaulted by strangulation, which additional autopsy findings supported, according to The Pierce County Sheriff's Department, which serves the area around Tacoma and investigated Whitney's case.
Whitney was 18 years old when she died. At the time, Pierce County detectives tried to develop leads as they searched for the person responsible for her murder. As the investigation began, they interviewed people who knew Whitney and people who dated her. But despite collecting DNA samples from the body, which presumably belonged to the killer, investigators were unable to locate a suspect.
This matter remained unresolved for years. In 2005, another attempt to find the suspect by running those DNA samples through CODIS – a national database that law enforcement can use to link forensic profiles to crimes and suspects called the Combined DNA Index System – ultimately failed. Proved unsuccessful as no match was found, according to the Pierce County Sheriff.
Due to a grant from the Washington State Attorney General's Office, Pierce County Sheriff's cold case detectives did not submit the DNA to the genetic genealogy laboratory for re-testing until 2022. Genetic genealogy is a process where forensic analysts create a family tree from a DNA profile, which in this case allowed law enforcement to identify Whitney's killer through a family member.
According to the Pierce County Sheriff, findings from the genealogy laboratory led detectives to John Guillot, Jr., the biological son of their suspect in Whitney's death and confirmed that the elder Guillot was indeed a DNA match. Suspect Guillot died of cancer in January 2022, just eight months before the lab returned a DNA match that implicated him in the murder.
“There was no known connection between Tracy and Guillot Jr. and detectives believe this was a stranger kidnapping, rape and murder,” the Pierce County Sheriff's Office announced in a social media post Saturday. Whitney's case has been resolved. “Our Cold Case Unit is always looking back at the past in an attempt to find answers for families like Tracy's. We are glad they may finally have an answer and some closure with solving this case.”
Although Whitney's killer was never prosecuted, her relatives told a CBS News affiliate Kiro They feel some sense of peace knowing that he has been identified. His sister, Robin Whitney, said she hoped publicly identifying Gillot would help solve other cold cases, as she believed he may have committed several crimes during his life.
“We believe John Guillot Jr. may have possibly committed other crimes,” Robin Whitney said in a social media post, according to KIRO. “However, since he is deceased and due to existing legal restrictions, his DNA cannot be uploaded to CODIS (Law Enforcement DNA Database). We hope this policy can be re-evaluated, as it may lead to additional cases. Can help solve it.”