The figures do not track with any reliable source. According to FBI statistics, of the 2,451 homicides of black people in 2014, 90% were committed by black people as opposed to 8% of the cases where offenders were white. That is high but so is the ratio for whites. Of the 3,021 homicides of white people in 2014, 82% were committed by white people while 15% of the offenders were black. It is hard to see how someone came up with the stats in the tweet. While the number of whites killed by blacks is roughly twice that of blacks killed by whites, it is still far short of the suggested 81% of white homicide victims. The difference is just seven percent above the rate for whites killing blacks. Even if you factor in lower number of blacks in society into weighing this percentage difference, it is still far less than what was presented in this retweet. Moreover, the statistics show that the overwhelming likelihood is that people are murdered by people of their own race.
There is plenty for us to argue about in the criminal justice system, but as the late Senator Daniel Patrick Moynihan said, “You are entitled to your opinion. But you are not entitled to your own facts.”