Almost always, if the shooter is white, and sometimes regardless of race, and over say 40, you are going to see alcohol abuse, and debt, failing marriage. No doubt he likely was deeply racist, and these other issues, exacerbated by the alcohol, set him off, and the fact he was likely carrying a gun at the community pool, which is a gun control issue, separate, but related.
It's really not a lot different from the ISIS related lone wolfs, these people are autonomous, and though the places they choose to carry out their murderous rampages are related to proximity, it would seem random to bystanders and victims. There is little to predict their behavior, other then things many people keep deeply hidden, racisim (the kind that has you kill at random), debt, etc. Yet, as has been said, we have an admin wanting to keep out refugees of genocide, and Muslims, of any nation, where I think statistics will show, race related, domestic terrorism, is likely an equal, at minimum threat to people....but what people?
You can't fear monger and demonize aging white men effectively to aging white men.