Another common thread that has been explored, is a possible link between Donna Lass and the Zodiac Killer. According to former police officer Harvey Hines "During the time she worked in San Francisco she lived at 4122 Balboa Street with a roommate named Carol Emerich. Emerich was also a nurse. According to the employment records, Lass was working a late night shift in October of 1969 when the San Francisco cab driver, Paul Stine, was killed by the Zodiac."
This, bearing in mind the disappearance and likely murder of Donna Lass only eleven months later, along with the alleged Zodiac 'Pines' card mailed on March 22nd 1971, it is something not to be overlooked. It may be coincidence, but the 'Pines' card does reveal an interesting feature, long believed to be from the hands of a hoaxer because of the victim count not marrying up with known Zodiac correspondence. However, it does in fact fit perfectly into the Zodiac timeline.
But what if the Zodiac moved in the circle of Donna Lass, knew the young nurse, or even worked alongside her. His confidence in these surroundings was evident after the murder of Paul Stine in Presidio Heights on October 11th 1969, apparent by his detailed account of events in the November 9th 1969 'Bus Bomb' letter. He may have lived in the Vallejo area and worked in San Francisco, hence the copious mailings to the San Francisco Chronicle newspaper. If we could tie this person to Donna Lass through San Francisco and South Lake Tahoe, and possibly Cheri Jo Bates at Riverside, we may inch a little closer. The 'Pines' card may be suspect Zodiac material, but the wording on the postcard does leave a subtle hint that a connection may exist.
It all lies in the wording "Sought Victim 12", considered by some an error on behalf of its sender. But if we examine the victim count of the Zodiac Killer, the past participle of seek, indicated the killer may have been targeting Donna Lass during her residency in San Francisco some four months earlier.
"Sought Victim 12" suggested that the Zodiac Killer at some point in his recent history had trailed victim 12. Bearing in mind the 'Pines' card was supposedly referencing the disappearance and murder of Donna Lass on September 6th 1970, then it isn't a giant leap of faith to believe that the murderer was searching for victim 12 relative to his timeline and the young nurse.
On April 20th 1970 the Zodiac Killer mailed the '13 Symbol' cipher claiming 10 victims. On June 26th 1970 the killer mailed the 'Button' letter and Phillips 66 map claiming 12 victims. His search for victim 12 was clearly over, according to him, therefore it couldn't have been Donna Lass, who was abducted just over two months later. However, she may have been the original target. If she had been earmarked as victim 12, as hinted by the 'Pines' card, his plans were clearly thwarted or sidelined.
Friends and colleagues of Donna Lass included Carol Emerich and Jo Anne Goettsche, the latter of which visited her around the time she disappeared, and it is these friends, or persons close to them, that may hold the key to the identity of the Zodiac Killer during that crucial month in 1970. When the killer mailed the 'Pines' card on March 22nd 1971, either by accident or design, his mask of anonymity may have slipped even further upon pasting the words "Sought Victim 12," and place him a lot closer to Donna Lass than we care to imagine.