 all the way up to your contacts, what messages you were sending, who were you calling. From an investigator's standpoint, it's just the most critical piece. Here he says what he would be looking into is who, if anyone, the alleged gunman was talking to right before the shooting, what sort of planning went into this. And that sort of information, he says, usually can be found on a phone. Whether that's going to be the case here, we just don't know yet.