Wasn't the perp, too? Or is his whiteness cancelled by that of the vics?
We need to work up some theory about this. Basic data would include the Outrage Factors appended to the Zimmermann verdict, the OJ verdict, the Reginald Denny verdict(s), and various shooting episodes (Littleton, Phoenix, Blacksburg, etc.), and the various flashmob attacks on Caucs. (Reminder: we need a new, derogatory, creatively insulting and demeaning word for European-Americans. "Ofay", "Honkey", and "Gray" are dated, and "cracker" is too regional.)
I suspect he was, although - if he wasn't - we may not learn about it for a long time.
But - just a thought experiment - suppose he was African American. Do you really think the MSM would pay any more attention to the attack than the tiny amount they have?
The only race could have been used as a "hook" would have been if more than one or two of the victims had been A-A, or if the attacker had made racial remarks during or after the attack.
IIRC, one of the Columbine victims was a Black teen, male.