So the question becomes was DR involved in any way and listing him as a POI was justified, however not enough evidence has come to light to prosecute him, or was he listed as a POI in a rush to find "someone" to investigate to keep media and public pressure off the Sheriff's Department?
Too much we still don't know...this many years later.
What I find odd is the unwillingness to share information that might solve the case. This many years later, why is the Sheriff's Department still a closed door? If I were them, unless I was only missing one small piece of evidence to close the case, I would be welcoming anyone who could help with open arms.