Thanks for that Kaldin. Presume the cartridge rolled under the wardrobe.
Do you have a similar plan of the kitchen?
Seeing the bedroom plan was interesting for me, as clearly the primary focus of the killer was (at least initially in this room) the door side of the bed.
If a 'beserk' killing, you would target on the focus of your rage irrespective of the consequences i.e. Sheila hating her mother? If planned (money motivated) you would take out the biggest threat who was clearly Neville.
As you say, the order is crucial. Has it been definitively proved that the 'assault choreography' started upstairs, went down to the kitchen, then returned upstairs? Could it have also been kitchen, bedrooms, kitchen, bedroom?
Sorry - what I'm trying to express is somewhat clearer when it's just in my head!