Frankly, I see the note as being written before he went to the house that night on their paper etc. which means he was at the home before. If she was dead, there would be absolutely no sense in leaving the note behind.
Why leave the note?? He told us yesterday...he said her death was an accident. The note becomes evidence of that. He's very clever.
Hobbies per resume: writer/actor.
Go way back in his history to when he was a kid and we'll likely find that he was "queer". He's a geek, good looking and an introvert. Within a school or family situation he can function. Outside that, he can't.
I wonder if Karr might have tutored Jonbenet's brother at some point in time. But, if he was not in Boulder on the date in questin, there is no case -- unless he knows who did it.