The most reliable predictor of whether a defendant will be executed in America

Murderers who kill white people are much more likely to be executed than those who kill blacks - even though black men make up the majority of homicide victims in America, according to a new study.

The study, which is called #BlackLivesDon'tMatter, examined the so-called race-of-victim effects in US executions from 1976 to 2013 and found "the single most reliable predictor of whether a defendant in the United States will be executed is the race of the victim."

Although black males represent only 12% of the population, they make up about 50% of all murder victims in the US. Even so, their killers are unlikely to be charged with a capital crime, which would make them eligible for the death penalty.

Among the 1,359 inmates executed between 1976 and 2013, only nine out of the 534 white inmates executed had a black male victim, the study pointed out.

"Black men, especially among the relatively young, have a statistical risk of homicide victimization many times higher than any other racial or gender group, " the researchers wrote, "but their killers rarely face the death penalty."

If you look at individual states, the race-of-victim effect is even more apparent. Florida has never put a white man on death row for murdering a black man, and it has occurred only once in both Texas' and Alabama's history, according to the study.

As the study notes, these troubling findings are nothing new. The idea that racial bias disproportionately affects the justice system has been suggested before.

Researchers in Georgia who examined over 2,000 murders in 1983 found those accused of killing white victims were four times more likely to be executed than those accused of killing black people, according to the study. Since then, 82% of studies done on the topic have reached similar conclusions - despite the fact that federal law forbids discrimination based on race.

"This research shows that even in the absence of explicitly racist policies or people, there are substantial racial disparities at work in our criminal justice system," a London School of Economics blog post pointed out. "Put simply, #BlackLivesMatter is anything but redundant."