Indeed they should not. I've discussed this issue with working cops. Usually the counter-argument is that black people statistically are more likely to have criminal records & use violence against police.
Granted that criminal justice statistics are dubious at best, they're also irrelevant. Police take an oath to preserve, protect & defend the constitution of the US & of their state. The 14th amendment forbids agents of the government treating people differently because of their race. That is not equal protection under the law.
Cops need to understand that their feelings are their own—how can you demand an officer who feels black people constitute a greater danger to him than whites just change how he feels? But their actions belong to us, the public.