[CoLawman]

I would concentrate my efforts on the cellphone usage. All tolls and all towers that the cellphone was pinging off of to retrace his steps and his contacts on that day/night.

The fact that the phone was on they should have "pinged" it to determine geographical location of the phone. I assume they did this, but then again, perhaps not.

There was a statement that the phone was inactivated and then reactivated, this does not happen without recorded phone calls for request of service. Again when the phone was reactivated "pinging" would have positioned the phone within a certain tower range.

There are some other thoughts and procedures but will assume "all" the bases were covered, making my comments redundant.