May 4 (UPI) -- Detectives in California say they hope to take advantage of the same DNA technology used to capture to alleged Golden State Killer last week to solve the 50-year-old mystery of the Zodiac Killer.
Law enforcement officials in Vallejo, Calif., and San Francisco and Napa counties are re-evaluating potential DNA evidence left behind by the man who killed five people -- but claimed dozens more -- in the late 1960s.
The identity of the killer -- who identified himself as "the Zodiac" in cryptic, bragging letters to Bay Area newspapers -- has remained a mystery to police for nearly five decades. For a time investigators believed Arthur Leigh Allen, of Vallejo, may have been the killer. But a DNA test in 2002 was inconclusive because technology at the time didn't allow for a clean sample to be extracted from the glue on envelopes the killer used to send the letters.
Vallejo Police Det. Terry Poyser said his team has resubmitted two envelopes to a lab for new analysis.
"They were confident they would be able to get something off it," he told The Sacramento Bee.
Poyser believes he'll have the results of the testing within weeks, at which point he plans to test the DNA against an expanded pool of samples used in genealogy research. Police used this technique last month to nab Joseph James DeAngelo, the suspected Golden State Killer or East Area Rapist.
Sacramento County investigators submitted a DNA sample from one of the crimes -- he is suspected in 12 deaths and at least 45 rapes between 1976 and 1986 -- to GEDmatch, a public database of genetic genealogy people use to track down blood relatives. Matches from distant family members and the reconstruction of a family tree led police to DeAngelo.
Vallejo police sent their samples for DNA testing months before the break in the Golden State Killer case, but investigators say they're encouraged by the new possibilities.
"If we get a good profile, then you start tracking back," Poyser said. "It really comes down to DNA. Without it, you have nothing. It's a 50-years-old case."
Most investigators believe the Zodiac Killer is dead. His last verified letter was received in 1974, a few years after his final confirmed kill -- and Allen, a convicted child molester, died in 1992. But the new DNA test could lead police to a relative, and Zodiac's identity.
"There is no reason in the world why they shouldn't make another run at all the DNA in this case, especially considering what has happened in the Golden State Killer case," Tom Voigt, an amateur Zodiac Killer expert, told the San Francisco Chronicle. "There were more than 20 letters sent, and lots of other stuff on file. Just send it all to a lab."
In his letters, the Zodiac Killer claimed 37 murders, but police have definitively linked him to five:
-- On Dec. 20, 1968, he shot and killed David Faraday, 17, and Betty Lou Jensen, 16, high school students on a date on Lake Herman Road, considered a lover's lane in Benicia in Solano County.
-- On July 4, 1969, he shot and injured Michael Mageau, 19, and killed Darlene Ferrin, 22, who were parked at Blue Rock Springs Park in Vallejo. The killer called police the next day and confessed to this and the Lake Herman Road attacks. Mageau was able to describe the shooter to police.
-- On Sept. 27, 1969, he stabbed and injured Bryan Hartnell, 20, and killed Cecelia Shepard, 22, college students picnicking at Napa County's Lake Berryessa. The killer also called police about this crime and linked it to the previous two attacks with a note penned by a black marker on Hartnell's car door.
-- On Oct. 11, 1969, he fatally shot Paul Stine, a cab driver, in the Presidio Heights area of San Francisco. Three teens who witnessed the incident worked with police to provide the only composite sketch ever produced of the killer.