I agree. This kid must have been full of a jealous rage against his sister. It sounded like everything revolved around her, her looks, her talent and the all consuming beauty pageants, I doubt there was much time left for him.
For what it’s worth the DA later stated that DNA found at the crime scene removed the family members from suspicion. And then later this happened;
In 2002, the DA’s successor took over investigation of the case from the police and primarily pursued an alternative theory that an intruder had committed the killing. In 2003, trace DNA that was taken from the victim’s clothes was found to belong to an unknown male; this discovery induced the DA to send the Ramseys a letter of apology in 2008, declaring the family “completely cleared”.[8] In February 2009, the Boulder police took the case back from the DA and reopened the investigation.