Why not?
What we do know is that he's a nut who developed a fascination for the Polly Klass and JonBenet cases, going so far as to move to where the Klass murder happened. He seems to have some weird fantasy thing going about being involved in those crimes, but there's no evidence he was.
As with most high-profile crimes, lots of crazies have "confessed" to this crime, but the DA ain't splainin' why they are taking this one seriously. But then, it's Boulder.