Black Lives Matter Protest?

You've missed the point.  BLM isn't protesting black people getting killed.  And BLM isn't protesting a white cop killing a black perpetrator who is attacking the cop.  BLM is happy that police locate & arrest black perpetrators - particularly ones who have committed crimes against other black people.  THAT'S ALL FINE.

What BLM doesn't like is when the American justice institutions (the cops, the prosecutors, the grand juries, the courts) seem to follow different procedures when a black person is killed by a non-black person, particularly when it's a cop.  In such instances, it is clear that the justice institutions have TROUBLE handling the killer in the SAME way they handle black killers of black people.  They have TROUBLE arresting the non-black killer, TROUBLE with charging him, TROUBLE arraigning him, and definitely a lot of TROUBLE convicting and incarcerating him.  They often decide not to bring charges, or drop them once they're brought, or fail to return an indictment, or decide "not guilty" at the last moment.  It's a pattern that clearly exists, AND IT ONLY EXISTS WHEN THE DECEASED IS NOT WHITE.  BLM simply wants everyone to NOTICE that pattern and start WONDERING if it could be due to something other than coincidence.  (America has a peculiar history when it comes to black people and white police, you know.)

In this case - as you can see - there was NO move on the part of the Minneapolis PD to even charge Officer Chauvin.  They had TROUBLE with that.  The County Sheriff's office finally took him into custody.  Who knows how much TROUBLE the People of Minnesota would have had charging, arraigning, and prosecuting him, had BLM and other groups and individuals not made a POINT of saying "LOOK everyone!  Pay ATTENTION to this!"