This is a brief section from the account of the three teenagers who observed the subject in the taxicab at Presidio Heights on October 11th 1969. But why was the Zodiac Killer spending valuable time attempting to hoist Paul Stine into an upright position behind the steering wheel, when he should have been making good his escape? If the Zodiac had been aware of the three teenage eyewitnesses, it seems unlikely he would have spent an unnecessary period of time tearing a piece of shirt, then compounding the situation by trying to maneuver Paul Stine into an upright position, before casually walking north on Cherry Street and taking no evasive action upon seeing the approach of Donald Fouke and Eric Zelms' patrol car. But what was the purpose of raising Paul Stine, who was covered in blood, into a more visible position to the casual passerby? It would seem the taxicab driver out of view would be the better option in delaying his discovery and any resulting search. Here is one possibility.
After Paul Stine had been shot - and either slumped or was pulled into a lying position - the Zodiac Killer had to gain access to the back of the taxicab driver's shirt. The Zodiac Killer, having entered the right front passenger seat, likely gripped the jacket of the victim and pulled him towards and to the right, with Stine face down in the passenger side floorboard. This is where the largest pooling of blood was located and where responding officer Armond Pelissetti ultimately discovered the stricken taxicab driver. It is evident that the jacket of the victim has been pulled upwards - an obvious necessity to gain access to the rear of Stine's shirt and tear a portion of the fabric. But in maneuvering the body into this position, the jacket had bunched up and may have become wedged between the victim and passenger seat. Once the Zodiac had acquired the shirt piece, he may have wanted to conceal this fact by pulling the jacket back down over the victim. However, there is one big problem - he cannot easily achieve this with the jacket trapped between seat and victim. The Zodiac Killer attempted to elevate the victim upwards to free the jacket and pull it back down over the shirt, but from the passenger side, with dead weight, achieving the leverage is extremely difficult - and Stine inevitably fell back. The Zodiac Killer exited the vehicle, traveled around the taxicab and opened the driver side door - and with his right hand braced on the dividing panel (leaving the blooded fingerprint) attempted to haul Stine back into an upright position, to where he can now release his right hand in order to pull the jacket down over Stine's exposed back - but he ultimately failed. The teenagers may have mistaken the killer simply attempting to elevate the victim, as trying to prop him back behind the steering wheel. This cannot be proven as the objective of the killer, but it could be argued that the only function of altering the position of Paul Stine inside the taxicab after the fact, was to alter the visible scene viewed by responding investigators.
The next portion of the police report is crucial: "P.E.H. ambulance #82 responded, steward Dousette, victim was examined and pronounced dead at 10:10 pm." Later Toschi and Armstrong would arrive: "A check with the Yellow Cab Co. revealed the victim arrived at work at approximately 8:45 pm and had only one fare prior, that being from Pier 64 to the Air Terminal. Sgt. Falk responded in G-10. Homicide inspectors Armstrong and Toschi responded and took charge. G-40, Lt. Kiel also responded". But by the time Inspectors Toschi and Armstrong had arrived, the victim had been pulled from the floorboard of the passenger side into the position seen in the crime scene photographs. This was undertaken by responding medical personnel to determine the status of Paul Stine (likely to check for vital signs), before pronouncing him deceased at 10.10 pm.
Once the police had finished their assessment, the victim was taken away from the crime scene. At what point in the investigation did they become aware of the missing shirt piece? Was it the Zodiac Killer's intention to somehow delay its discovery, so his declaration in the October 13th 1969 letter had the maximum impact and shock value, upstaging the police, who believed this crime was nothing more than a routine robbery and taxicab murder at this point. The whole reason behind his attempted crime scene manipulation.
According to Robert Graysmith "Stine's body was the first to be autopsied that morning, a little after 9:30 am. Before the blood and grime are removed, close-up photos are made of the body fully clothed, under the guidance of the pathologist. Stine's blood-stained clothing had been removed, an identification tag wire put on each article, and placed under a drying lamp. When his clothes had dried completely, they were laid flat, with butcher paper between each article to avoid the possibility of any sort of transfer. The clothing was listed on a clothing slip and turned into the property clerk's office to be safeguarded for future lab tests". So, at what point did investigators learn of the missing shirt piece - before Zodiac mailed the October 13th 1969 letter, or afterwards.
On October 12th 1969, the San Francisco Chronicle ran an article on the murder, entitled 'Robbery Victim' - "A Yellow Cab driver was found shot to death in his cab last night, the victim of an apparent robbery attempt in Presidio Heights". On October 13th 1969 the police issued a wanted poster, lumping this crime in with other taxicab robberies, with the poster carrying the message "Wanted for murder and robberies of cab drivers. Suspect takes cab in downtown area at 9:30 pm and sits in front seat with driver. Tells driver destination is Washington and Laurel area or area near park or Presidio. Upon reaching destination, suspect orders driver to continue on at gunpoint into or near park where he perpetrates robbery".
The police still appeared to consider this a simple matter of robbery, with the suspect possibly having taken a small amount of cash, the driver's wallet and the keys to the taxicab. But what thief would take the time to carefully tear a rectangular portion of the victim's shirt and remove it from the crime scene? This fact alone, should have told investigators they were not dealing with the routine robbery of a taxicab driver and thereby associating it with other robberies committed in recent weeks. The removal of the shirt piece should have set this crime apart, had they been aware that a piece was missing. Is this what the Zodiac Killer had envisioned when he mailed the October 13th 1969 letter, gaining the element of surprise and getting one over on the police? Or did the police know all along that a section of shirt was missing - with the removal of the shirt piece being deliberately withheld from publication as to verify any future contact by the killer? But why label it as a routine robbery to both the press and public alike, when it was anything but.