What is particularly troubling about this case, outside of the obvious (
innocents were murdered), is the fact that this guy may have made/received a call to/from someone prior to the attack. (
link,
see 1 minute mark ) If he actually made contact with someone, it would be so easy to ditch the phone during the ensuing panic... a phone that could have been a burner phone, and thereby not even be registered to him, making it tough for LE to sort out.
I listened to the witness interview, and he said that JH answered a phone call. It may have been JH making his own phone ring (no incoming call) and using that "call" as an excuse to slip out the back emergency exit. Otherwise it would have looked a little suspicious and someone could have taken more notice.
The good thing, though, is that LE has all the phones dropped in the room - and all the stuff that JH had on his person and in his car. I'm betting they are looking at every phone there. Any phones with calls in or out during that time period will be closely scrutinized. They would be very interested in any phone(s) that JH had with him - because there could be many other clues about his actions in a phone.