marty theer was not robbed. it was a very, very cold night, not a night where a prowler would be out on the streets just looking to find someone. it made it very suspicious. keith morrison: investigators couldn't imagine who would want to kill such a wonderful man like captain marty theer. but of course, out in this dark parking lot, they didn't know any of what you know-- not yet, anyway-- assuming what you've heard so far is the real story. and as you'll see, the question of what was true and what wasn't could be very tricky indeed. michelle said she'd gone back to her office, because she'd forgotten something. so what took so long? coming up-- greg butler: they found a candy wrapper that had been opened and in the trash. it was almost like a scene, where she had just gone upstairs and sat and waited for a few minutes. craig melvin: for what? when "dateline" continues. let's say you're deep in a show or a game or the game. on a train, at home, at work. okay, maybe not at work. point is at xfinity. we're consta