I would think that he had noticed over the past few years all the media attention missing wifes and mothers get. SP was young, beautiful, had young children. I would think he had been thinking or fantisizing about killing her for quite sometime, at least a couple of months and had at least planned some or all of it as perfectly as possible. He just seems so arrogant and self-assured, his face says to me "All of you think you know so much, you don't have a clue". To me the dumbest way to dispose a body would be to try to sink it in water, look at SP with Laci, or bury it -search dogs or searchers would find it.
This whole case bugs me and his attitude. I just can't believe he would have been so stupid with all the evidence that is coming out now, it just seems so obvious? But, then again maybe his arrogance got the best of him and he thought he was smarter than everyone else. But, for petes sake, to put a body in a container, ask your dopey step brother to help you get rid of it, I mean come on, how stupid can you be. And the warmth thing bugs me about the container, if a person is in either a plastic barrel or a rectangle containor, you could feel the warmth? To me that would be a maybe yes, more likely no. But I could be wrong. Just pure speculation.