The man suspected of killing an 18-year-old Federal Way woman in 1988 was identified eight months after he died of cancer, closing the cold case.

On Nov. 30, the Pierce County Sheriff’s Department revealed in an online post that a suspect had been found in the 1988 cold case murder of Tracy Whitney. According to the post and an accompanying video, DNA swabs were taken from her body, and multiple people who knew or dated her were interviewed, but the case went cold for years.

In 2005, the DNA was sent to the Federal Bureau of Investigations Combined DNA Index System, but no match was found. However, after the Washington State Attorney General offered a grant in 2022, the sheriff’s department submitted the DNA found on Whitney to a lab for genetic genealogy, and a match was found for the suspect.

“Unfortunately our suspect, John Guillot Jr., had died a few weeks prior. Detectives matched the suspect’s DNA to Guillot’s biological son to confirm Guillot Jr. was the suspect,” the post said. “There were no connections between Tracy and Guillot Jr. and detectives believe this was a stranger abduction, rape and murder.”

Details of the murder

On Aug. 28, 1988, Pierce County deputies responded to a call of a body found in the Puyallup River near Sumner. Fishermen had located the body of a woman who was nude where the Puyallup and White Rivers meet, according to the sheriff’s department.

Following the body’s discovery, detectives were called to the scene. An autopsy was performed, revealing that the woman’s cause of death was asphyxia caused by strangulation and probable smothering. She also had several blunt-force injuries and was believed to have been sexually assaulted. Her death was ruled a homicide.

Two months later, the woman was identified as Whitney through dental records. According to a video on the incident posted by the sheriff’s department, Det. Sgt. Lindsay Kirkegaard said that through the investigation, there were many suspects, including current and previous boyfriends, and there were rumors of who could have been involved.

Kirkegaard said that on the day of her murder, Whitney was last seen at a Burger King in Federal Way arguing with her boyfriend, and less than 24 hours later, she was found in the river deceased. Kirkegaard said multiple people were interviewed, but the investigation stalled, and the case grew cold.

Kirkegaard said they were able to submit the evidence to to a lab for genetic genealogy, which revealed that the DNA matched Guillot, though he had died of cancer in Jan. 2022, eight months before the results were received. Kirkegaard said nothing in the investigation suggested that Whitney had known Guillot, and this murder was most likely a stranger abduction, rape and murder.

Because of Guillot’s death, no charges could be filed against him, and the case was then closed due to the death of the offender.

Tracy Whitney with her younger sister. Courtesy of Pierce County Sheriff’s Department