Forty years after a 15-year-old girl was stabbed to death in Northern California, DNA has led to the arrest of her suspected killer, prosecutors announced.
Karen Stitt was last seen on the night of Sept. 2, 1982, heading toward a Sunnyvale bus stop after spending time with her boyfriend, the Santa Clara County District Attorney's Office said.
The next morning, her naked body was found about 100 yards from the bus stop, according to prosecutors.
The Palo Alto teen had been sexually assaulted and stabbed 59 times, prosecutors said.
Stitt's boyfriend was cleared based on the DNA evidence left behind at the scene, prosecutors said.
Decades went by without a major lead, prosecutors said, until investigators turned to genetic genealogy, which uses an unknown suspect's DNA to trace his or her family tree.
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Genetic genealogy made headlines in 2018 when the novel investigative tool was used to find the Golden State Killer. Genetic genealogy takes an unknown suspect's DNA left at a crime scene and identifies it using family members who voluntarily submit DNA samples to a DNA database; this allows police to create a much larger family tree than if they only used law enforcement databases like CODIS.
Through genetic genealogy, the search for Stitt's killer last year narrowed to four brothers from Fresno, California, including 75-year-old Gary Ramirez, prosecutors said.
Investigators then "used traditional investigative techniques to start eliminating the brothers one-by-one," Santa Clara County Deputy District Attorney Rob Baker told ABC News via email Wednesday. "After extensive investigation, we felt confident Gary was the source of the crime scene evidence."
Last week, the district attorney's crime lab confirmed Ramirez's DNA matched the sample at the murder scene, prosecutors said.
On Aug. 2, Ramirez was arrested at his home in Maui, Hawaii, prosecutors announced Tuesday.
Baker said he's surprised Ramirez's DNA was not in CODIS, adding that Ramirez has no criminal record at all.
Gary Ramirez served in the U.S. Air Force in the early 1970s after which he spent time in Northern California, Southern California, Colorado and Hawaii, according to prosecutors.
Ramirez is due in court in Hawaii on Wednesday for extradition proceedings, prosecutors said. Once in California, he will be arraigned on murder, rape and kidnapping charges, prosecutors said.
Information on an attorney for Ramirez was not immediately available.