If you had Lori's cell phone and laptop, AC's cell phone and laptop (if he had one), MB's cell phone and laptop, and CD's cell phone and laptop, I think you could go a long way toward solving this. Having Tylee's phone (which they found in HI) and JJ's laptop (? maybe in storage?) would possibly add to incriminating evidence.
Communications in the cloud (even if deleted from a device), phone location GPS, online searches / map searches, e-mail receipts, photos/locations/time stamps, purchases, etc.
Do we know how many of those devices authorities might have?