How would this intruder know exactly which room was the one JonBenet slept in? He was able to snatch her from her bed without her making noise that would wake up other family members. He then took her to the basement and murdered her, without anyone hearing anything. He then went upstairs and wrote a 2 page ransom note. The killer must have been the Invisible Man. No wonder they can't find him.
IT WAS A MANSION. A HUGE HOUSE. They had a party that night, many people in and out. Forget it...you're small mind can't wrap around larger concepts.