This and this are probably the best overviews I could find about what has and hasn't changed. It's a little frustrating though -- it's hard to find something substantial about "okay yes but what has the result been."
And, the things I could find about the result sometimes used very weird metrics (like lumping together all police shootings without making any effort to distinguish justified shootings from unjustified or attempting to determine what percentage were unjustified in order to point to whether that number is going down or not).