What Is the Shepherd's Bag?

There are no telltale signs of sexual assault on Maryland that could be easily determined. Her body positioning on the bed is a little weird, you know, so things aren't quite adding up. Sam couldn't account for everything and it does seem like an odd crime scene with this husband who is useless. It's just trying to reconstruct his movements and a stranger's movements in order for this to all add up from just an evidence standpoint.