He was 9 at the time, and I know the police investigated him, but I don't think they found anything. He'd have to have been pretty devious to hide evidence of a murder and I don't think most 9 year olds can do that. The whole family were examined, and nothing conclusive was found, but who knows?
Burke Ramsey was not involved in the murder of his sister, JonBenet. DNA evidence taken in 1999 cleared him, since it did not match DNA at the scene of the crime. It is suspicious that he slept through the entire event, but he was young and likely did not know what was going on.
Burke Ramsey, brother of JonBenét, speaks publicly about his sister's unsolved murder. It is unfair to speculate as to whether or not he was involved, he was after all her brother. If he wasn't involved, I feel he would feel even worse thinking that the general public feels that he killed her.
I don't think that Burke, JonBenet's brother was involved in her murder, but I would not be surprised if some other family member had a part in this. It is just too strange and suspicious, especially because it remains unsolved after all of these years. I think the brother just wants answers.