The one thing we know for sure about the Zodiac Killer was his propensity to respond to newspaper articles concerning his exploits, or potential victims he may be responsible for. Bearing in mind his switch to the Los Angeles Times, let us take a look at the previous article regarding the Zodiac Killer in the Times newspaper prior to March 13th 1971. One week earlier, on March 6th 1971, the newspaper revealed that the body of Lynda Kanes (20) had been discovered alongside Howell Mountain Road in a shallow grave 15 miles west of Lake Berryessa, and noted that she was a Pacific Union College student just like murder victim Cecelia Shepard. In other words, the newspaper had tentatively connected Lynda Kanes to one of Zodiac's attack sites. Enter the Zodiac Killer, writing to the Los Angeles Times the following Saturday, claiming at least 17 victims. But this may have just been the primer.
The Pines card was clearly suggesting an involvement in the missing Donna Lass case because of the pasted wording "pass Lake Tahoe areas" and "sought victim 12". But the key part of the Pines card may have been the "around in the snow" phrase, pasted upside down, as if to suggest a burial site. Lynda Kanes was found buried in a shallow grave, just like Judith Hakari. So, if the Zodiac Killer could suggest he was the murderer of Donna Lass, who was linked to Judith Hakari, who was buried in a shallow grave - the timing of the Los Angeles letter, coupled with the Pines card, may force investigators to consider the possibility of Zodiac's involvement in all three murders. Hence the victim total rising by three to 17, with Donna Lass to be also found buried.
The Zodiac Killer, had he read the March 6th 1971 article about Lynda Kanes (shown left), would have realized that his name was brought up because of the proximity of the murder victim's gravesite to Lake Berryessa. He would also have known, had he read the September 26th 1970 article about Donna Lass, the close proximity of the murder of Paul Stine and his claimed escape into Presidio park, to the workplace of Donna Lass at the Letterman General Hospital in the Presidio grounds. By linking himself to Donna Lass, he is adding credence to his claim through proximity, and hoping investigators would draw this conclusion too.
This makes perfect sense when we consider that the April 20th 1970 Zodiac letter claimed 10 victims, and his June 26th 1970 Zodiac letter claimed 12 victims. Any victim "sought" between these two dates could conceivably have become Zodiac's twelfth victim. Donna Lass was resident at 4122 Balboa Street, San Francisco between the dates of April 20th 1970 and the early part of June 1970, before she moved to begin her job at the Sahara Tahoe Hotel & Casino on June 6th 1970. A Zodiac Killer trailing or having "sought" Donna Lass before her move to South Lake Tahoe, could have unquestionably targeted her as victim number twelve between these dates. By using the phrase "sought victim 12" in the Pines card, the Zodiac Killer is effectively connecting himself to Donna Lass through San Francisco and South Lake Tahoe, hopefully cementing the belief in investigators minds that he knew Donna Lass over an extended period of time. Of course, he may not have been trailing her at all and may not have been her killer, but by using the "sought victim 12" phrase, he is effectively suggesting this as a possibility to law enforcement in order to boost his credibility.
The information about Donna Lass having worked at the Letterman General Hospital in the Presidio park, close to the Zodiac's final victim of Paul Stine on October 11th 1969 was widely covered in the September 26th 1970 San Francisco Chronicle article, along with the date she moved. Therefore, by incorporating the phrase "sought victim 12" into the Pines card, the Zodiac Killer is bridging the gap between the murder of the taxicab driver and the disappearance of Donna Lass, both indelibly connected to the Presidio Heights district of San Francisco. This phrase wasn't a mistake, it was deliberately fashioned to plant a seed. The Los Angeles Times would form a similar connection to the murder and burial site of Lynda Kanes to the Zodiac Killer's attack at Lake Berryessa. Therefore, the Zodiac Killer mailing two communications immediately after the discovery of her body may have been designed to engineer a conclusion that the Zodiac had not only killed Donna Lass and Judith Hakari, but Lynda Kanes also. The Los Angeles Times letter came nearly five months after his previous communication, but only one week after the discovery of Lynda Kanes' shallow grave, with the passage "I'm writing to the Times (because) they don't bury me on the back pages like some of the others".
The murder of Lynda Kanes would eventually be attributed to Walter Williams (aka Willie the Woodcutter), who was ultimately convicted of the crime.