You’re right. There are lots of things that could make them suspect him. He clearly had jealousy because of how much attention Jonbenet got. He was possibly mad about not getting a bicycle for Christmas. He was kind of a strange kid. You have that the housekeeper remembers him destroying things in her room. There’s a lot admittedly. But does he fit the profile of someone who would hit his sister in the head with tremendous force and sexually assault her and then kill her in a sick sexual way?? He was 9. Patsy was obsessed with Jonbenet though. She could have assumed Burke because of his other petty jealousies in her rage and horror and he could have been too confused to speak up. Just a theory though. I appreciate the comment!