The Federal Bureau of Investigation has data about murder and race in the U.S., you can view their website for yourself. My reading of it finds the following for the most recent year on record, 2012:
Whites murdered - 3128, whites killed by other whites - 2614.Meanwhile, the U.S. population is roughly 319 million, of which whites are roughly 80% and blacks are about 13%. Meanwhile blacks suffer roughly 46% of the nation's murders, over 90% of them committed by fellow blacks.
Blacks murdered - 2648, blacks killed by other blacks - 2412.
Whites killed by blacks - 431.
Blacks killed by whites - 193.
Overwhelmingly, we are at-risk from others of our own race, not from people of other races. And black people are particularly at-risk from other blacks.