First, the Golden State Killer—now the Zodiac Killer? With DNA evidence possibly pointing to the former, police say the same method could help identify the long-sought Zodiac Killer, NBC News reports. Police in Vallejo, Calif., say they sent two envelopes from the Zodiac Killer to a private lab for a new kind of DNA analysis months ago. Any clear genetic profile will be given to a family-tree DNA service like the one used in the Golden State Killer case. But can DNA from envelopes and stamps dating back nearly 50 years still be used? "It's definitely possible," says a forensic scientist. "If they didn’t steam the stamp off and it was stored in a cool dry place, maybe there’s sufficient DNA left."
Vallejo police Detective Terry Poyser, who's had the case for four years, tells the Sacramento Bee that people at the lab "were confident they would be able to get something off it." In a surprise twist, lead suspect Arthur Leigh Allen—an ex-school teacher and known child molester who died in 1992—was cleared in 2002 when an incomplete DNA sample from the envelopes didn't produce a match. Modern DNA technology should get a better sample, although Allen was known to get friends and neighbors to lick envelopes for him, so police may ask those people to submit samples. "There are probably 30 different circumstantial things that point to [Allen]," says Poyser. "He was extremely intelligent but a deviant dude." (Read more Zodiac killer stories.)