Some of these "facts" are actually in the Supreme Court document. Some seem to be proven, others seem to be just accepted under the "rules of common experience".
The police officers went to check out this house on 22 September, which is when they found these blood spots, but it hadn't been sealed off.
There
were some traces of human and animal blood, but were they
all blood spots? What did they use in situ? A U/V torch? If so, it's not only blood that would show up. It would then be up to be lab to determine what they could.
Body fluids such as saliva, semen, vaginal fluids, urine, and perspiration give off fluorescent light when illuminated by a source of ultraviolet light, which is a very efficient method for detecting such stains in a crime scene or in objects collected from the scene, such as clothing, towels, bed sheets, or decorative items. Even dried stains become fluorescent under UV light.http://www.enotes.com/topics/ultraviolet-light-analysisThey may have used other tests in situ, but it's not clear.