The worst that can happen is that an innocent man is convicted of this murder because he is strange, deluded, and because everyone in both the Boulder DA's office and the Boulder jury pool want him to be guilty. They are sick of this case and embarrassed at how it was handled from the beginning.
I think barring any strong, compelling evidence against him, Karr is not guilty, but will be railroaded into a guilty verdict.
I was making that "worst that can happen" comment with regards to the DA's office view of it.
I agree with you, unless some specific public evidence that demonstrably excludes him comes forth, he will be indicted and prosecuted. and there is a good chance of conviction. whether he is guilty of this or not, the guy is a sicko and a pervert, and a jury hearing his own words and letters and taped phone calls, will convict him.