Well, it certainly appears to be the case that there is a photograph of a footprint. I am prepared to assume that it is a photograph taken in the kitchen depicting a footprint in Ralph's blood. But, I am (at least currently) not prepared to assume or accept that the footprint was made by Sheila. Indeed, the photographs of Sheila on the bedroom floor do not show any blood at all on either of her feet. So, who cleaned the blood from Sheila's foot? Presumably Mike, you would say that EP cleaned the blood from Sheila's foot? This theory is quite ridiculous but I suppose that it is no more ridiculous than the theory that Sheila herself, having killed 4 persons, engaged in some form of ritual cleansing of her foot/feet.