EU,
If Sheridan was tested years ago and it came back as "cannot be excluded", then why wasn't he arrested then? Why wasn't there any follow up? Any interrogation? Any search warrant issued on his property?
I just don't understand why the FBI would spend the time, money, and trouble DNA testing a guy, have it come back as a hit, and then provide absolutely no follow upon him.
Because all the DNA test can accomplish is eliminating a suspect. It is of no value in Court to prosecute someone.
It may well be that only 1 out of 1000 suspects cannot be eliminated after comparing the samples. For my purposes that's enough to say someone was DBC. On the other hand, a criminal defense attorney is going to get the FBI to admit that they're not absolutely certain that it was even DBC's tie. He'd argue there are 1000 men in America who could have owned the tie based upon population at that time--and he'd be right. Therefore, the tie as a piece of evidence would be inadmissible.
Additionally, it would be argued that the destroyed cigarette butts were exculpatory evidence further compounding the prosecution's case.
In reality, short of an outright smoking gun, the case cannot be prosecuted. When I say smoking gun, I mean either the money being found or the hand written notes from Flo being found.
Of note, you would think that if it came back that Sheridan couldn't be eliminated that the FBI would dig further into his time in Nepal. Well according to Sheridan the FBI did just said. He wrote that they investigated his time in Nepal and even interviewed the doctor who was there when his daughter was born. That said, I have never been able to prove this so I don't know one way or the other.
In either case, the FBI was never presented with Sheridan's passport--which I have photographed. And, when the FBI asked him about the whereabouts of his then-wife who could provide an alibi (or the opposite), Sheridan said she died in 1977--a claim that has apparently been proved false by multiple members of his family, including his daughter born in Nepal.
All of that said, Sheridan was never arrested or charged.