The police are going through a public relations nightmare. Perception of policing is increasingly seen as threatening rather than helpful. This is largely due to the proliferation of murders carried out by police officers that have been captured on video.
When a police officer in the America murders somebody, other officers mostly attempt to protect their own brand and badge as best as possible. In any other industry, colleagues and competitors in the same field would denounce the actions of an individual who operated outside the rules of conduct.
Obviously not all police are bad, but rather than attempting to protect the image of law enforcement, the police (not prosecutors) would gain more credibility by speaking out against those who abuse the badge.
Until this happens, police all over the country will continue to be targets of skepticism, disrespect, harassment, and violence. This will lead to ‘trigger-sensitive’ police, who end up killing good people over trivial confrontations.
This is not an issue where a side needs to be taken. It makes complete sense, with complete consistency, that one could appose both the killing of back people by white police as well as the killing white police by black people.