The Zodiac Killer shot Paul Stine as he was performing a run-through stop, after all this was believed to be an unscheduled pickup, en route to a dispatched call at 500 9th Avenue. The bloodstains on Paul Stine's shirt and the fingerprints on the driver side door, as well as other points of interest, seemed to suggest that after Paul Stine was shot the taxicab motioned forward, out of control and the Zodiac Killer determined to secure a trophy for his master plan, quickly exited the rear of the taxicab, accessed the driver side door and after stepping over Paul Stine leaned against the body to gain some form of limited control and coast the taxicab to the intersection of Washington and Cherry Street where he secured his memento. For a more detailed account of this sequence of events, along with blood pattern analysis, visit the link on the right.
It is a 'most dangerous game' trying to apply logic to the most illogical of all killers, but some things the Zodiac Killer did were logical. His attempt to remove fingerprints from the inside of taxicab, including the compartment area and the driver side door were born out of logic, he did not want to get caught. So is it possible the removal of the wallet and keys were taken from the scene for the exact same reason, they harbored his fingerprints. We know that the three teenagers from across the street thought they saw the murderer searching through the victims pockets and this in all likelihood is correct, as Paul Stine's wallet had been taken. There have been many suggestions that the killer also took Paul Stine's driving license, but this is unconfirmed and no evidence exists to suggest this was the case. In fact, if one wanted to be awkward there is actually no evidence to suggest he took any items, other than the shirt piece he tore from the victim.
If you were the killer of Paul Stine on October 11th 1969 and you were determined to secure a trophy to prove you were inside the taxicab that night, what is easier, searching the victims pockets for a personal photograph, a drivers license or some other form of ID card, or carefully tearing a rectangular section from the victims shirt tailpiece, which would without doubt take up far more time and ultimately increase the risk of detection or at worst capture. The killer wanted proof and he wanted it fast. If he had found Paul Stine's driving license, it seems bizarre he would then start searching for further trophies and almost surely it would have been unnecessary. This would seem to suggest he found Paul Stine's wallet, but it did not contain the proof he needed, so continued on to remove the shirt piece and like a jigsaw, would without doubt, place the letter writer and the murderer of Paul Stine under one banner, the Zodiac Killer.
In the police report it states 'Suspect should have many bloodstains on his person and clothing, suspect may also be in possession of the keys to the Yellow Cab, possibly his wallet belonging to the victim'. But why did he take these items, they were never sent to the authorities by the Zodiac Killer and would have been too bulky to have been received via the standard letter route. Even if the Zodiac Killer had wanted to place them into an envelope, he never did, so why did he take them. Is it possible he took them as a possible future trophy, but changed his mind. This seems unlikely, as he had ample opportunity to send them to the San Francisco Chronicle from the time the first section of shirt was received on October 13th 1969, until the second section of shirt was received, contained within the Melvin Belli letter on December 20th 1969, but he chose not to. Instead he chose to send a second piece of Paul Stine's shirt, and despite numerous letters after December 20th 1969 the keys and wallet were never sent. It may not be conclusive, but in all probability he took the keys and wallet for a totally different reason. A reason that was nothing more exciting than simple common sense.
The only question left, is why did he touch the keys in the first place: The answer lies one block east.
We have conjectured that after killing Paul Stine at the Washington and Maple Street intersection not everything went to plan and with the taxicab motioning forward out of control, the Zodiac Killer had seconds to react, by accessing the front section of the car and setting the taxicab back on track. It is here things may have unfolded slightly differently to the previous analysis, albeit not much. It was to be the very reason he took both the wallet and the keys one block later.
Although we cannot prove this and it is just speculation, it again fits with the known facts.
When the Zodiac Killer attempted to regain control of the errant taxicab at the Washington and Maple Street intersection, the car may have stalled and he was forced to restart the engine. His fingerprints were now in evidence and the rest is history.