John Allen Muhammad, a member of the Nation of Islam, and his younger accomplice, Lee Malvo, were serial killers who targeted white people in the hope of starting a race war. They killed 17 people and wounded 10 others. More: Beltway sniper attacks.
Hastings Wise killed four co-workers. Like many spree killers, he then tried to kill himself, but he was found alive. More: Hastings Arthur Wise.
Nathan Dunlap killed four co-workers and wounded another. More: 1993 Aurora shooting.
Colin Ferguson killed six people and wounded 19 others. More: Long Island Rail Road massacre
A handy list of white victims of police abuse, or Why #BlackLivesMatter should be #AllLivesMatter
A handy list of female mass murderers
ETA (from the comments):
US Mass Shootings, 1982-2015: Data From Mother Jones' Investigation
How common are African-American mass shooters? | theGrio: "The percentage of black assailants who kill on a scale such as Monday’s Navy Yard shootings is about equal to the percentage of black Americans, says former FBI profiler Clint Van Zandt."
Are Most Mass Murderers Really White? | American Thinker:
— a comprehensive list dating from 1982 through 9/16/2013 is found at Mother Jones here — and guess what?
Of the last 20 mass killings of that period, 9 were perpetrated by non-whites.
That would be 45 percent, which exceeds non-whites’ 37 percent share of the population.
Of the last 30 mass killings, 11 were committed by non-whites — right at the 37 percent mark.
And what if we go all the way back to 1982? We then have 66 mass killings in which the races of the perpetrators were known, and 22 of them, or one-third, were at the hands of non-whites. Note here that America’s demographics have been changing, with non-whites comprising only about 20 percent of the population in 1982; thus, if we consider an approximate average non-white population of 28.5 percent during the 31-year period in question, it appears that, again, mass murderers are slightly disproportionately non-white.
In other words, there is no evidence whatsoever that mass killings are a characteristically white phenomenon.
And there never was.
In fact, the group most disproportionately represented on the Mother Jones chart is Americans of Asian descent. While only 6 percent of the population, they have been 15 percent of the 31-year period’s last 20 mass killers, 13 percent of the last 30, and 9 percent of the last 66. This is quite interesting, too, since Americans of Asian descent have a very low crime rate in general.