A white cop shot a black man in suburban Minneapolis, was charged with many of the same infractions this cop was charged with, and wasn't convicted. For every incident you mentioned there are many more where the cop is either not charged or not convicted.
If there was justification for the shooting, usually the cop is cleared (as he should be); this cop shot this guy for no good reason at all.
"Justification" usually is summed up by the cop saying he thought that his life or the life of others was in danger. They're claiming that there was a loud noise that startled them so he shot. Officers have walked away for less.
You’re right, but by and large those days of unquestioned cop shootings are over. Heck, in LA they even re-tried the Rodney King cops 25 years ago until they came up with the right verdict. “Civil rights violations” are the catch-all when a jury doesn’t arrive at the politically-correct verdict.