More like what the moron in the LV shooting was doing, going out in what he considers a blaze of glory is my guess.
Likely-suspect-grade possibilities - my speculations - abound:
* Murderous crazy like Nicholas Cruz;
* Gang @$%;
* One of the many thousands of felons Federal courts forced the State of California to release early or a violent criminal who pled down to a crime that got a jail term rather than prison (Thanks, Proposition 140!);
* Rando homeless dude;
* Terror attack by a Jihadi or a drug cartel or human trafficking outfit.
The dead shooter's name is known to police but has not yet been released. Apparently a news conference is planned for this AM.