Ken - thank you for your analysis. Your description of Occam's Razor was indeed very interesting. I believe that when most people become a member of a jury, they take that charge very seriously. They are charged by the judge to be the "finders of fact," and in essence, "finders of truth." They are urged to determine what really happened. They may not be aware of the defined term of Occam's Razor, but I believe that when they get in that jury room, that is the principle that they eventually employ. First, they do it on a piece-by-piece basis as you so eloquently describe. They will look at every piece of evidence and determine its value and they will not set it aside and forget about it. In this case, the mask strap has meaning, the mask pins have meaning, the snorkel mouthpiece has meaning, the missing slate has meaning, the fin has meaning, the dive buddy system has meaning, Swain's shop and lifestyle has meaning, romantic desires have meaning and the money has meaning. Every piece of evidence must fit into a narrative to tell the complete story, and no piece can be left out.
And when the jury completes the narrative story for each side with all the pieces, that is when jury finds themselves able to determine a verdict. The side with the weaker case will try to prevent a completed narrative story and focus only on small pieces and try to ignore the other pieces. The side with the stronger case will do everything they can to complete the narrative story for the jury that includes all the pieces to illustrate the realistic differences between the two stories. You will notice that is exactly what the prosecution did when they cross-examined Swain. They brought-up each piece of the story and forced David to deny, deny, deny, but there was no explanation from him. They got him in such a mode of denial, there were some things he didn't need to deny, but he denied them anyway. But what they achieved with their cross-examination was the narrative story with all the pieces included. Nice, short and succinct because all they got from David was denial.
Ken - you believe that the evidence shows "staging" of the fin and the mask. However, this really is the more complex story for the jury to understand. If they are to accept "staging" then they have to understand the mind of Swain and ask themselves "why." A difficult thing to understand and would require some explanation of a psychologist. I would have to agree with the prosecution's approach that the evidence shows a struggle between two human beings. It basically accomplishes the same thing as David being responsible for what happened to all the equipment and is a simpler argument for the jury to understand. When they look at the mask strap, the pin and the snorkel mouthpiece, it is a profound moment for them, they see struggle, a far more compelling and emotional response from the jury. However, I think that if David were to get a second bite at the apple, the prosecution may need to argue "staging" of the fin.
I think that the simplest explanation for the moment of drowning is that David first jerked the mask off of Shelley's face, a struggle for the mask ensued and then he jerked the reg out of her mouth and she drowned. I agree that it was not necessary for him to turn her air off, far more time-consuming and more difficult. If he went for the reg first, there is always the possibility that she could see him, or feel him behind her, kick him and swim away from him. Every diver knows it is far more stressful to lose your mask than to lose your reg. In addition, if he went for the mask first, it would be difficult, if not impossible for her to see that it was him attacking her and it may have been important to him that she not know it was him attacking her.
In this case, it really is the defense who has the weaker case and must keep the narrative from being completed with all the pieces. They had to focus on trying to poke holes at the prosecution's pieces and ignore the rest and hope that the jury forgets about it. Pieces for attack by the defense would include the prosecution's calculation of air usage to try and prove that David was a liar and was with Shelley at the time she died. The police's ineptness at understanding the difference between a reg and a snorkel mouthpiece. The mystery of the fin could serve as a distraction to keep the jury's attention away from the other evidence. All the other prosecution's evidence such as the mask strap, pin, snorkel mouthpiece, missing slate, diving around a confined but deep dive site for more than 20 minutes never looking for Shelley, never seeing Shelley, not seeing the fin near the mooring line that he ascends, stopping of CPR, slowing down of calls for help, desire for another woman, inevitable loss of dive shop, financial woes and the gain of a large financial sum which is spent extravagantly and quickly - all these are difficult for the defense to take a position of strength. They can only try to defend, try to explain or ignore. They can possibly explain the mask strap and pin with panic, but not the snorkel mouthpiece or missing slate. This ultimately gives them the weaker case because once you start having to explain away or ask the jury to ignore so many things, the harder it is to win.
