@Armchair Detective
I did not say that Essex Police accidentally picked up four spent cartridges. You can't accidentally pick something up with your hands. But there would have been a lot of police activity in the main bedroom and officers would have moved from the kitchen to the main bedroom, each a focal point, and cartridges could have got stuck in boot treads and been kicked around. You also have to remember that the trajectory of cartridges is not linear; once ejected, they can bounce anywhere in the vicinity. If the killer is shooting from the landing or stairs downwards, cartridges could bounce back on to the landing and then end up in the master bedroom, as that's where the main police footfall is.
I don't accept that you can just create any scenario and interpret the evidence however you like. I find the suggestion rather condescending, since it's not what I am doing. In any event, this is a discussion forum. I don't mind you and Adam coming up with your own scenarios and commenting on, critiquing and criticising mine. I do mind being trolled. It's annoying.
Anybody who accepts Adam's scenario has to resolve certain problems. Why is June shot first? How does Nevill escape from the main bedroom? How is it that Nevill is shot in bed but leaves no blood in bed? How is it that blood is absent from the carpet of the upper main stairway, yet Nevill must have been bleeding and putting his hand to wounds? What about the stairway walls? The bannister? Did Nevill deliberately not take hold of the bannister or touch the stairway walls so as not to make a mess? Why doesn't Jeremy catch up with him?
Sorry for the confusion QC, I could have worded that better, I know you didn't mean they had bent down and picked them up with their hands, here:
To explain the casings you now have experienced SOCO's or TFG unwittingly picking up casings on the soles of their boots and all four of them get walked upstairs and deposited again in the bedroom.No officers trained to be observant in a crime scene notice that they are disappearing/reappearing . None dislodge from the boots ?on the stairs or in any other rooms and the casings in the boys room remain undisturbed, (perhaps they were more careful in there) - why didn't the clumsy oafs walk in the blood too? Sorry but I'm not buying it, it was the SIO that was unprofessional with his assumptions, the rest made some mistakes but knew enough to be careful in a crime scene.
Here's a thought though, why not have JB move some of the casings to make it look like Nevill went to June's aid?
I do agree that if NB doesn't go upstairs it solves some minor problems but in doing so, you create new ones that require just as much head scratching and supposition.
Adam's scenario is essentially the one the police believed the most likely but to save arguing about the unknowable, how about I just put your theory in the maybe pile along with all the others.