I heard this somewhere recently and it made me go, really? So I thought I would double check.
Indeed, one is more at risk to be murdered as a black person in America than as a police officer.
For 2013 and 2014 I get an average of about 80 officers killed on duty per year (this excludes correctional officers, traffic accidents, a few other categories.) That's a rate of 9.0 per 100,000 (based on 885,000 officers).
Meanwhile the homicide for blacks in 2013, men and women, is 15 per 100,000. (Based on a black population of 41.7 million and 6,261 homicides in 2013.) That's crazy. Blacks are three or four times more likely to be shot and killed as on-duty police officers.
[Now of course one could quibble that cops are only on duty 1/6 of the time and a good chunk of cops never see the street. Meanwhile being black is a 24/7 job. So hour by hour it might be more dangerous to be a cop. But stop quibbling. Even with a flawed comparison, sometimes you just need a stat just to smack you on the side of the head.]