I read late last night, it is something they could usually trace back to someone specific, but haven't been able to do so in this case... so what could that physical evidence be? The specific quote from the article I've linked below is as follows: " Ives said: 'Even though at the crime scene there was a lot of physical evidence of one sort of another which would lead logically to one person or another, it never led to one particular person.'
So? What could or should have logically led to one person or another, but didn't? Theories?
-> Did he leave (intentionally or not), a device of some sort at the scene? Electronic device? Prosthetic device (serial numbers can be used to trace these to maker etc). Was he diabetic and left something related to that there?
-> what could he have done that they thought they should have been able to trace back to someone specific?
-> some hint of employment?
2. We've only heard about Libby's phone having taken the video / audio evidence. Did Abby have a phone? If so, where was it? Who has it now?
(Former prosecutor in unsolved Delphi murders of two teens says they had signature elements | Daily Mail Online)