Information, please

I would appreciate views, speculations, etc., on why it is so important to discover the motive behind the Las Vegas massacre. Law enforcement considers this crucial, and I my post is not meant to be critical in any way of the hard work being done toward that end.
I just would like those, who are many, with more knowledge than I to tell me what your thoughts are.

Thank you in advance for any insight you care to give.

I would have preferred the opinions of the board but in desperation went to the internet and found that the main reason seems to be to provide closure for the victims' families.

I would also speculate that: 1) the idea that someone with seemingly no motivation could do something so horrific is very frightening, and 2) if there is no discernible motivation, there is no way to screen for such people making legal gun purchases. The only solution to #2 is to deny everyone the right to own assault weapons, and there is a large segment of the US population that won't accept that solution.

Makes sense, Badger. Thank you for your post.