I enjoyed having my ignorance fought by the article What’s the racial breakdown of people killed by cops? but it never got around to answering the OP.
The stated question was:
Dear Cecil:
I keep seeing a stat saying Americans are eight times more likely to be killed by a police officer than by a terrorist. How does this data break down into black, white, Hispanic, and Asian-American?
— Eric Ward
So, the question remains unanswered.
Cecil states that the FBI reports of Americans killed by police officers is “surprisingly steady over the years, fluctuating between 300 and 462”, so let’s take an average of of 386 per year. That means, from Jan 1st 2001 to Dec. 31st 2013, we’d expect about 5,018 total, which is more than the 2,605 Americans killed in the September 11th attacks, but not 8x more. So it looks like a safe bet that a random American in the past 13 years is roughly twice as likely to be killed by a police officer than a terrorist.
Now let’s see how the answer changes if you are black. Cecil says about 30% of the police killings are black people, who make up 13% of the population.
If we assume that 13% of the 2,605 Americans killed on Sept. 11th 2001 were black, that’s 339. And if 30% of the 5,018 police shootings were black, that’s 1,505. It’s still not 8x as much, only about 4.4 x as much.