As the taxicab approached the corner of Washington and Maple Street, Paul Stine did not place the car into park, knowing he was on a 'run through' to his original fare at 500 9th Avenue, radioed to him by Yellow Cab dispatcher Leroy Sweet, when suddenly the killer raised the gun into Paul Stine's eye-line. It clearly states on the autopsy report there were dark marks on the dorsal side of the Paul Stine's left hand, that may suggest that as Paul Stine reacted to move away from the danger, his left hand was raised in order to deflect the gun away at the instant of firing, resulting in dark stippling marks. During this melee, Paul Stine inadvertently broke contact with the brake pedal, causing the taxicab to motion forward out of control, possibly towards the sidewalk. Wanting to avoid an imminent crash and alerting the entire neighborhood, the Zodiac Killer either lunges forward to grasp the steering wheel and clambers over to the front of the taxicab to regain control of the vehicle, or exits the left rear passenger door and enters the driver side door. He then has to push his body weight against Paul Stine (who remains in a sitting position), against the driver side door to access the vehicle controls and thereby coast the taxicab to the corner of Washington and Cherry Street where he finally parks up.
However, we have a problem; If the Zodiac Killer had jumped from the back seats to the front and gained control of the taxicab by leaning against Paul Stine, at the end of the journey, it would not have necessitated the murderer walking from the front right passenger side door to wipe down the exterior of the driver side door and panel. The fact he did indeed perform this action suggests at the very least he must have deposited fingerprints on it at an earlier time. As explained earlier, if he had hailed the taxicab by approaching the driver side door at Mason and Geary Streets with murder on his mind, the last thing he would have done was to touch the driver side door handle, an action that necessitates the later removal of fingerprints. If the Zodiac Killer had remained in the rear of the taxicab for the entire journey, why on earth after killing Paul Stine, would he be wiping down the interior driver side compartment of the taxicab, after all, there was no reason to have ever touched these areas. If he had opened the right front passenger side door with the express intention of removing a piece of Paul Stine's shirt, the only three things he needed to touch would have been the rear right door handles, the front exterior passenger door handle and Paul Stine's shirt, nothing else. The wiping down of the interior of the cab and exterior driver side door makes little sense, unless he touched it.
Donald Fouke, a police officer responding that night, recalled a man walking with a shuffling lope along the north sidewalk of Jackson Street, heading towards the intersection of Jackson and Maple. If, as hypothesized, the Zodiac Killer exited the moving taxicab at Washington and Maple, is it possible he injured his ankle or leg in the process, resulting in the 'shuffling lope' described by Donald Fouke from his patrol car. The direction of the Zodiac Killer also makes sense, in that, if he had killed Paul Stine at Washington and Maple without any mishaps, he would likely have been walking north along Maple Street towards the Jackson and Maple intersection, the direction he was ultimately heading when spotted by Donald Fouke, only he had traveled one extra block unnecessarily.
http://www.zodiackillerfacts.com/blog/mysteryquest-paul-holes-and-the-murder-of-paul-stine