So where does he get the blood on his shoe, in your opinion? Do we know which direction the latent print was directed? This seems to me to be curious and you seem to have a good idea about the layout of 1122.
Very curious. What's the next step? Where did the killer get blood on his shoe? The PCA presents as fact that the shoe print was heading in a direction that enabled the murderer to exit through the slider. What do you think, after looking at the space?
I'm understanding you to mean that he was coming up from the first floor (front) of the house. We may be using different directional terms here. Which side is the front of the house, to you? (Side with slider - or side with wreath on door?)
Just my attempt to understand. IMO.
All of this is just my thoughts, I am not an expert, MOO, etc. etc. Also, forgive all the talk of blood, I promise you, I'm not a ghoul, it's just inextricably relevant to the shoeprint evidence.
I think that this was a very bloody scene, based the public comments of a number of folks who actually went inside the house, which none of us have.
But I think an important thing here is that it's described as a latent print. So, not obvious or sharply clear to the naked eye. So it's possible that there was only a small amount on his soles, but enough to leave a print that was recoverable. They did a presumptive test, and then they stained it with Amido black, which is used for a number of things, but one thing it does very well is enable latent prints in things like blood or blood serum to be clearly photographed for evidence. It reacts to the proteins.
I think he couldn't avoid getting blood on the tread of his shoes, especially if the reports we have of the attacks on the middle floor being far more active are true. Blood landing on the floor, him stepping forward to press his attack, stepping in the blood. None of these floors are carpeted, they're all lino, so that blood isn't going to be soaked up by the flooring, it's just going to spatter and pool, and eventually become tacky, and then dry.
Also, he walked around the house carrying a large knife. Unless he wiped it after every kill, there'd be drip trailing of blood from the tip of the knife which he may have stepped in, too, which could have increased the amount of shoe marks.
I think there were plenty of shoe marks through the house, by the way. The bloody nature of the scene, there wouldn't be just one. The reason why that one was used in the PCA is that it was clear, recoverable, indicated the path of the perpetrator through the home, and was corroborated by an eyewitness (and also helped support that eyewitness's statement as fact, not imagination, fabrication, or unreliable). The rest of the ones they recovered may be part of the trial, showing a likely path of movement and sequence of events of the whole attack, from the first murder to the exit of the home. They may even have earlier prints from his entry that are in dirt or vegetation or carpet fibres from his car mats. Those wouldn't be in blood, because whomever he attacked first hadn't bled yet for him to step in.
All very much my theories and opinions. If anything is glaringly, provably wrong, please correct me! I want to be basing my ideas on facts, not getting attached to something that can't have happened.
As for the house - I think of the front door with the wreath, as the front. The 'back' slider door - which actually points diagonally back and right - as being close to the back wall of the house. So, the windows of B, Xana, and the living room face the front. D's window, Kaylee's slider (also on the diagonal), and Maddie's window face the back. Does that make sense?
EDIT: Also, I have been using the terms bottom floor, middle floor, and top floor, because different geographical conventions for the term first floor, etc. make this way too confusing, otherwise. I live in Australia where that layout would be ground, first, second. But I think in the US, it would be first, second, third. Bottom, middle, and top is unambiguous.