My apologies if this question has already been discussed, but: If DN is a registered sex offender, wouldn't his DNA already be on file somewhere, like CODIS? And if so, why wouldn't LE have been able to find a match using the DNA (if any was recovered) collected at the Delphi crime scene?
A few of us have asked that question but I've not seen a definitive answer yet. I remember when LE was taking swabs from local sex offenders in the area at one point -- why would they do that if their DNA was already on file? Maybe all sex offenders don't have DNA in the system for some reason?