Not all of the victims were white. He only murdered 8 people and then killed himself, so at least one of the victims was black.

Although he did say he felt racially discriminated against at his job, that's not enough to say this was racially motivated. It wasn't some random shooting of "white" people just because he was racist.

What actually happened was he got caught stealing cases of beer from the warehouse and they confronted him over it and fired him. That's when he pulled out the gun and started shooting. This was more a case of a criminal getting caught than a racist hate crime.

[en.wikipedia.org]

I mean really, what "black" person in America these days doesn't feel they are being discriminated against? They are repeatedly told they are, so regardless of them actually being discriminated against, they feel they are and pull out that "race card" at the drop of a hat.