I have to admit I don't know every detail about this case, but what day was Laci seen walking her dog? Dec 23 or 24?
Additionally, the drapes were not opened the morning of the 24th, which is something she ALWAYS did.
Scott wanted her and the baby out of the way, he planned the disposal of her body and made all the preparations. Once the plan was in place, he killed her. He is one sick mofo.