Didn't FW say he himself moved the suitcase to under the window? I don't remember if he said why. And that he picked up some broken glass, put it on the suitcase? So his prints would be there.
JAR was supposed to have been in Atlanta, waiting after the movie to fly with his sister early the next morning to meet JR and his new family. But the evidence is an ATM photo showing just the top of someone's baseball cap, no face.
I don't have an opinion but a WS poster years ago when we were at a different "address" proved that it was possible he could have had time to make a trip in the night to Boulder and back. Her project was a very long one. Don't ask me to go into it. He couldn't have been the walker before dark who resembled him, who may have impersonated him in Waterford, Mi., maybe in Charlevoix also, if he really went to a movie with his pals and they didn't just cover for him as a teenage prank or something. He would have been no more suspicious than the friends, whether he was there or not, imo.
I have no favorite theory. but in the thread Why the Ramseys, I've posted some of a tentative one to just keep in mind, for why they'd cover for someone. There could be more reasons, I just can't think of right now. Like everyone else.