If we knew what smoking guns the sheriff may have found during the 2010 dig at DR's farm, it might be easier to lean towards DR as being Jacob's abductor. Without t knowledge, we're evaluating circumstances and profiling possible abductors based on their histories, behavior, location and alibis.
If Jared believes DAH was his abductor, it's difficult for me to fathom why the sheriff ruled this person out.
Does the victim's belief carry such little weight?
With regard to what Jacob's abductor might have looked like, I keep thinking how dark it was on that isolated road and how frightened the boys were. I've heard kids refer to 30 year old adults as being "old," because it seems anyone over 25 is old to them. Then there is the mask -- it appears that the boys could not see any detail in the face for obvious reasons. As far as the man's physical stature, I think he was dressed all in black, further obscuring a clear view of his physique. The kids were under great duress. I think their main thoughts centered on Oh my God what is that man going to do to us?
A thought about how could DR quickly do anything with Jacob during the interim time it took the police to get there -- did DR have a place already in mind in which a gagged kid could be put without anyone hearing him? He may not have necessarily done anything to Jacob until later. The only problem I have with this is the dogs not following a scent to wherever Jacob might have been hidden.