I had a few thoughts about reports that TC may have been seen jogging on February 12th. It's mentioned in the timeline video in following link.
http://www.11alive.com/mobile/artic...imothy-cunningham-grows-to-15000/85-526307239
(I forget when the possible sighting occurred -- think it was late afternoon or early evening.)
I assume the police asked about a bunch of questions to try to substantiate this:
Of the person who said they saw the jogger -- How sure are they that it was TC? How well do they know him? How sure are they that they saw him on Monday, Feb 12th rather than some other day? What was the jogger wearing? Where was he and what direction was he going?
Of TC's friends and relatives -- Does he jog regularly? Where does he go? What does he wear when jogging? What shoes does he wear? Does he jog even when he isn't feeling so well? Does he usually take the dog when jogging? (My guess is that even if he'd done so in the past, the dog is getting old, so not taking him not be that strange.)
(Regarding whether TC jogs when not feeling well, while TC's calling in sick might make it less likely that he went jogging, many runners and hikers -- I'm in the latter group -- will go out and exercise as long as we don't feel too bad.)
LE has said that anything that one can think of that belongs to TC was found in the house. But he had to be wearing something when he disappeared. If he typically went jogging in sweatpants and a sweatshirt, or similar clothes, and had more than one pair, it might be hard to tell if one set was missing. It might be easier to tell if running shoes were missing, but he might have more than one pair.
While his family's comments about their interactions with him before he disappeared make me think he may have been suicidal, if it really was him jogging, that might put a different spin on things. Jogging seems a reasonable and healthy way to deal with stress and clear one's head. Speculatively, he might've gone home, taken a nap, and then pulled himself together and gone for a run.
As several people here have mentioned, if TC went jogging, that might explain why the house was left locked, why provisions weren't made for the dog, etc.: He thought he was coming back. He might've taken a spare key with him.
If TC did go for a run, what happened? He could've met with foul play -- a random crime. Or he could've had a medical problem -- he was under stress and a bit overweight. If he'd had a medical problem, one would think he would've been found by now, but who knows. If he met with foul play, an assailant would've had reason to remove the body.
There's an intersection between "TC was suicidal" and "TC went for a jog and met with foul play or had a medical event." If TC was under great stress, he might not have taken safety into consideration and might've run somewhere he might not normally have gone or might not have paid enough attention to his surroundings.
Of course, we don't know for sure he went for a jog. But if he did, it might change the case considerably.