Indulging in some speculation:
* Whether a terrorist is a Jihadi or a white supremacist, their purposes if they perpetrate an incident like this would be lots of blood being shed and a big publicity splash;
* Murderous twit lived and bought his weapon in Fallon, NV, well over 300 miles' and about 5 hours' drive from Gilroy;
* Murderous twit grew up in Gilroy and attended, if not graduated from, Gilroy HS;
* Depending on his route, murderous twit drove through 3 or 4 cities with minor league baseball teams (Reno, Sacramento, San Jose, with Stockton being route dependent); he also drove close to the SF Giants' and the Oakland As' stadiums as well as near the minor league stadium in Modesto; without checking schedules, it's safe to guess that several of these teams had games that weekend (lots of attendees), and parking lot security would have been less tight.
That murderous twit bypassed much easier closer opportunities strongly suggests that his purpose was to hurt the people and town of Gilroy, not some sort of jihadi or white supremacist terror attack.
Keep in mind that my speculation plus a fiver will get you coffee and change at Starchucks.