I'm saddened for my country and hope that this can be a turning point for all of us.
I'm not saying the police doesn't do wrong, they absolutely do. We have examples of rapes, unjustified murders and beatings, entrapment. They are extremely rare. I think last year the police in the US killed 9 unarmed black men and 21 unarmed white men.
400 ... where there are videos. We know that until a video emerges these get swept under the rug, so I'm willing to bet that there are a fair few more than 400 examples of police brutality.
Now, how many are unjustified? That's the important question.
Your use of "unjustified" is entirely subjective. I don't know what your specific threshold is for justified violence against peaceful protestors, and it's a waste of time to try and guess what that threshold is. It's a waste of time for us to filter the data, only for you to then point out two videos you disagree with and ask everyone to repeat the same work over and over again.
All of the raw data is available to you in a list format. If you think there are errors, then fork the repo, file a pull request, or create an issue. Make your own list that demonstrates your point.