Incredible! After deaths of Alton Sterling, Philando Castile and Dallas police officers, cops are fired, demoted, suspended for Facebook comments about Black Lives Matter | McClatchy DC These people took an oath to serve and protect all people regardless of race and color. Just do your damn job, and check your racism at the door. If you want to be racist on your own time, in your own home, that's fine. Just don't bring it to work! Heads need to continue to roll. If racism is going to affect how you do your job, get another job!
When I served in the military I was keenly aware that my freedom of expression was more limited than a civilian. The amount of action that the government was able to take against me relative to a typical person was much higher. Commissioned officers feel it even more. It is a crime for commissioned officers to criticize elected officials. It can, and has, resulted in courts-martial and the end to otherwise sterling careers. Outside of the military the restraints are far less severe. But a cop making a comment about how they'd like to shoot a kid or how they would have shot a person an extra time for good measure goes beyond freedom of expression and crosses into that realm of things that, if you say them, adversely impact your ability to perform your job and/or diminish the credibility and dignity of the agency you represent.
It may not be preventable but it's not fine. The idea that someone can be racist "at home" that is, in their heart and mind, and that it will never spill over into their professional life is unrealistic.
I think if someone is truly racist in their heart and mind it is unrealistic to think it will never manifest itself is also unrealistic. The racist is probably telling racist jokes with their fellow racists or letting their theories on Obama fly over Thanksgiving dinner. If a racist was really and truly so good at hiding racism that no one beside them could ever possibly know that they were a racist then I'd say their relative harm to society would be minimal anyway.
Broken police oversight system rarely punishes cops This type of stuff could be part of the problem: Broken police oversight system rarely punishes cops - Chicago Tribune