JM may not have known about the search for Hannah Graham. Yes, it is very possible. Especially if he is indeed innocent of having anythnig more to do with here than having a drink and then going his separate way. It is NOT necessarily the case that had JM come forward immediately, he'd not have become a POI. FIrst of all, it is entirely possible, and IMO probable that he did have something to do with her disappearance. Second of all, whether he is or not, he could find himself in a the situation where he is all the LE have and as the very last person that could be traced being with Hannah, a lot of focus could be put on him. It does happen that people get under suspicion by the police when they are indeed innocent and get the criminal treatment by the police. Not unusual at all. Which is why attorneys will tell their clients not to talk to the police.
So what do you do if you are the last person who saw a missing person, and your attorney tells you not to talk to the police, given the circumstances? Especially someone with JM's profile. It is entirely possible that the dogs that were tracking Hannah circled where JM's car was parked--she could have touched his car walking by it--it could have been unlocked and she got in it. All kinds of explanations as to why she might be connected to the car with nothing to involve JM. But if there is evidence of Hannah in that car, JM is going to be in one hot spot. Statistically, given the scenario, LE is going to come to a very direct line, simple conclusion, that probably is the right one, but...not 100%. Strange curveballs have happened.
Right now no crime has happened. An adult woman disappeared. No sign of any harm to her has shown up (unless some evidence was found in that car). I don't believe that definitive proof of anything was found in that car or apt since JM did go to the police after that evidence was found, and they could not book him, could not force him to say anything. Apparently his attorney was spot on that he didn't have to talk to the police, as they had to let him go, though they clearly believed and believe now that he was culpable for something in Hannah's disappearance.
Since police will likely have JM in custody soon, albet for reckless driving and possibly giving a minor alcohol, we'll see what happens. When the evidence from car and apartment come back from forensics, there will be even more info, though how much LE chooses to share with the public will be determined. We'll see if they have to release JM without charging him with anything. Not sure what they can charge him with, even if there is evidence that Hannah was in his car and in his apartment, unless the evidence is pretty clear that something nefarious happend to her there.
As for the Lauren Spierer case--that' s one that I've followed very closely. The very last person to have seen her alive, as far as LE can track had her in his apartment, admits it freely and yet there isn't a shred of evidence that he did anything to her and that he knows what happened to her. LE couldn't touch him even knowing that she was there. No proof that she did not leave him alive and whatever occurred she left him, he has no knowledge about Still no direct evidence even that she is dead. I don't believe she's alive, but, yes, it is possible. IT has happened that young women who disappear, show up alive in various circumstances, much later. So that JM was the last person with Hannah regardless where or what the story might be, does not mean he killed her or had anything to do with where she is now.