murder of police vs murder by police - to be continued

How come white people and the white media can talk about the murders of police using such sentiment and words as it is "an unspeakable tragedy, and a vile and cowardly act" yet police murders of Black people are justified and not even prosecutable?

How come white people and the white media can see that "Tragedies that involve our men and women in uniform affect our entire city and touch every member of our law enforcement community," and not that police murdering Black citizens is more than a tragedy but a travesty of justice in our land?