I don't know.
And neither do you...
I mean about anything, because police keep all kinds of info to themselves. To me a key question hasn't been answered: when was LD killed? (not when was he found) and when was his last known sighting alive?
I also think it's key to know specifically when K&B left PA (date and time) not just 12 July.
Also, what they took with them.
People seem to be focusing on the end of this tragedy. It ended in a way that was very public, and easy to speculate about/criticize/discuss: there are some concrete people, places and things that we can ponder. IMO what they were up to hours, days or weeks before they left is more indicative of motive, ability, mindset, etc. And that is the stuff that LE might or might not release, and reporters might or might not pursue through a freedom of information request.
It's also easier to ask and answer "why would they go here or do that, etc" than to ask and answer what our role is in a society/culture that made these two and what's with our fascination after the fact...
Just to be clear, these are rhetorical questions and I'm wondering if anyone else is puzzling this out on this level...