The Aryan race are Iranians .
Certainly desired by Nazis.
Aryan - Wikipedia
Well, except the Nazis interpretation was quite different so it's not really the same.
We really don't have enough information to determine what this guy's motive was. It's hard to tell from a few instagram posts.
And there is not really a common profile that fits with all mass shooters.
What I have read from the past thirty years of research, though, there are a few factors that have played a role in the motive behind these types of shootings.
One is the desire for notoriety. They want to be seen as a hero standing up for a cause. They are looking for glory or attention. ( like Dylan Roof)
Another is, of course, mental illness. One study showed that about half of Mass shooters suffered from a mental health disorder. Adam Lanza had years of therapy with psychologists but never was found to have a disorder that would suggest violent behavior.
Another thing many have in common is a history of domestic violence.
The other thing some have in common is a sense of grievance. They believe they have been wronged by a person, maybe their place of employment, or a certain demographic group.
Other characteristics are that they are often resentful, paranoid, or narcissistic.
I'm sure there are others, too. It's probably hard to come up with any explanation that makes sense.
It's even harder to find the solution.
Imo