In oblivion, for instance, you could walk into somebody's house, walk right past them, and then go steal all their trinkets upstairs, and they won't even give you a second glance once they walk into the newly object-vacant room. there's no "hey, where's my stuff!" or "why are you skulking around upstairs," the same thing applies to murder, you can be dragging a dead body through the street without a second glance. I mean if the game allowed you to I'm sure you could dismember a guard's body and fling his limbs at people on the street and they'd just go about their business.
It'd be nice if this time NPCs would gain suspicions about you if they saw you doing something suspicious, such as if they see you in their house and then all their stuff disappears, they might lose disposition towards you, or might even run to a guard out of suspicion, in which case guards might be more willing to keep a close eye on you. Likewise if you murder somebody, and people had seen you around the victim previously, then they might gain the same sort of suspicions, or even put two and two together and find out you did it, depending on any circumstantial evidence. Not sure how hard such a thing would be to implement (depends n the extents of it), but just throwing the idea out there..