Approximately seventy minutes after the attack on Bryan Hartnell and Cecelia Shepard at Lake Berryessa, the Zodiac Killer made a payphone call to the Napa County Sheriff's Department from a payphone located near the corner of Main and Clinton Streets, just slightly north of the old Sam Kee Laundry Building, now a wine tasting bar called Vintner's Collective.
He stated "The receiver on the phone the Zodiac used was put down, but not hung up. Technology then was not like it is today. The phone company could only report that the call came from a pay telephone somewhere between Lake Berryessa and Napa. The Napa County Sheriff's Department wanted to find the phone, and fast, so virtually any official with a radio was asked to help. This reporter jumped into action. After a brief stop at the Sheriff's Department, I drove north on Main Street. Driving past a car wash and the historic Sam Key Laundry Building, I spotted a pay phone, but thought the call must have come from closer to the lake, nearly 30 miles away. At the last second, though, I swerved my car toward the phone booth and was shocked to find the receiver off the hook. I used my own two-way radio back to KVON where I instructed the on-duty deejay to call police. They, in turn, told me not to move until officers arrived." Napa Valley Register.
In the 2007 Zodiac documentary he stated "As I sat there I could hear voices in the background and traffic. So I called the Sheriff's Office on another line and kept the one line open. The Sheriff's Office had broadcast, I had possibly broadcast, I'm not exactly positive, that this person had left the phone off the hook. As it turned out one of the local reporters for the newspaper had heard this broadcast on his scanner, and so he started driving around the city of Napa to see if he could find the phone, and he was the one who actually saw the phone. He was then yelling "can you hear me, can you hear me," and I could hear the voice, and that's how we located the phone."
They were able to confirm that this was the correct payphone because police dispatcher Dave Slaight kept the connection alive, making contact with Pat Stanley.
However, when Pat Stanley yelled "can you hear me, can you hear me" to Dave Slaight, had he picked up the receiver, accounting for the fresh palm prints recovered by police upon arrival, or was Pat Stanley simply shouting down the phone as it lay on the shelf. Some accounts state that the latent prints were effectively useless because of how they were recovered. One would suspect that responding personnel would have cross examined Pat Stanley as to whether he had handled the phone, thereby eliminating him as the contributor of any latent prints lifted from the receiver.
Why though, had the Zodiac Killer chosen this payphone? It wasn't located directly en route to Vallejo (assuming he lived there), suggesting the killer may have had some previous knowledge of downtown Napa. Perhaps he had previously frequented some establishments in the area of the payphone. The quickest and most direct route from Lake Berryessa to downtown Napa is via California State Route 121. Then you have to break off west and travel 1,100 meters (0.68 miles) away from State Route 121 to find the payphone. The alternative is heading west along Lincoln Avenue or Francis Street, then traveling south on Soscol Avenue, which brings you out on Clinton Street by the payphone.