The problem is that the statistics don't show the claimed bias. Normalized on a per-police-encounter basis, white cops (or cops-in-general) don't appear to shoot black suspects more often than they shoot white suspects. However, police interact with black people more frequently, so the absolute proportion of black shooting victims is elevated.

Can you provide any sources for this?

The fact that the incidence of police encounters with blacks is elevated would be the actual social problem worth addressing, but the reasons for the elevated incidence of police-black encounters do not make a nice soundbite.

Is the incidence of police encounters with blacks elevated?

What are the reasons?