Statistically, most serial killers ARE young white men. That doesn't mean there are exceptions to the rule, though. For example, there was Wayne Williams, a black man convicted of a series of murders in Atlanta back in the 1980s. There were also one or two female serial killers, including one executed in Florida recently.

There are news reports that Mohammed was stopped at least twice by police near the shootings but weren't even searched. It seems everyone was fixated on the "angry white male" profile (and perhaps the confusion about a white van) so they never checked out a couple black men in a Caprice.