It really *is* interesting that DM kept those gloves, when one really thinks about it. It was Friday suppertime I believe, when he got picked up by police.. meanwhile it had been the evening prior to that when he knew he felt the need to do all of the things he did that night, in order to conceal his crimes.
He knew police had already visited him at the hangar. He knew from his employee that someone close to the situation had suspicions and had potentially called police about the truck being there, DM had already fired him for that. And yet instead of disposing of the gloves, he kept them on his person. Gave different incriminating items to different people, thereby bringing them into it and getting them involved.
It wouldn't surprise me to learn someday that CN's letters *back* to DM, were also kept, perhaps at some rodent's house. I don't recall ever hearing that MB's home was searched for possible evidence? Wouldn't it have made sense to search there too? She went to DM's address and collected things after his arrest. It seems that for some reason, she felt the need to open the trailer door from inside her garage, otherwise, why would there have been a need to wipe the lock and the back end of the trailer, seeing as how it was mushed right up to MB's garage door?