I tend to think you must be right. I can't see how she would do this if she hadn't proven he was there. Depending on what kinds of records he left, it may be trivial for LE to locate him in Boulder on the night of the murder. So, I tend to think she's got him as far as him being in Boulder.
I check the airlines schedules the other evening. If one was to take a direct flight from Atlanta, leaving at approximately 4:00 pm, they would arrive at 5:00 pm Denver time.
You know what I think is interesting? karr's family wants book deals and movie deals. You only do that when their is a story to tell and the story would be if Karr really did kill JBR, otherwise there is no story.