It is likely you are right, but it is a mistake to jump to seemingly obvious conclusions without evidence, it is possible that it was a tragedy engineered to stir up anti-white sentiment, not as likely but stranger things do happen.

EDIT Seems this was a hate crime, however I stand by my contention that it is best to wait for evidence rather than to presuppose.

He probably was as evidence so far indicates

The demographic in Gilroy is fifty-seven percent latino and hispanic. The gunman had possession of white supremacist literature. I'd venture to guess this was a racially motivated hate crime, but we don't know everything about the shooter and his friends yet. This incident is likely to become more frequent, since our stupid ass, NRA-supporting congress persons don't officially care about how thousands of people are culled from our American population all the time. Until they outlaw the purchase of semi-automatic assault rifles, we all have that to control where we physically place ourselves.

Comments like this don't really help anything.

I guess for me the motive becomes secondary because it is hard to know if he opened fire on particular people or if he just fired in no particular manner. I was trying to tell from photos and info coming out of the scene to determine if this is a festival that is attended by mostly Hispanic and black people or if the crowd was fairly mixed. I do think it has a lot to do with hate, general nasty hate. Do we know his race and ethnicity? I've not seen a whole lot about his background and actions in my news feed yet. And I will also add that unfortunately since we now have a leader who has made hate and anger the norm and even beyond a norm it is now not only permissible but expected to display your anger and hate however you deem necessary. This is so very dangerous.

Already been made public: he was a white supremist.
" Investigators are aware of recent posts Legan wrote on Instagram that include white supremacist themes, multiple law enforcement officials briefed on the probe told ABC News. One entry, which criticizes the garlic festival, appears to have been posted Sunday from the event, showing crowds of attendees.

Another message posted Sunday criticizes people of mixed racial heritage and makes reference to a book popular among white supremacists, officials said."