Because more black people will commit a crime per capita. More whites are shot and killed by police every year than blacks.
Take a look at the statistics the Warshington Compost "dared" to show. They use the term RATE instead of total amount because RATE makes their argument look better.
https://www.washingtonpost.com/graphics/investigations/police-shootings-database/ Total blacks killed by police - 1,298
Total whites killed by police - 2,475
Almost twice as many whites have been killed by police, but we all know that blacks who are only 35% of the population commit 65% of the crime....
Actually, blacks are 13% of the population and they don't commit anywhere near 65% of the "Crime". The real problem. Cops are more likely to arrest blacks for petty offenses white people would get a pass for.
Now, here's the thing. YOu go after a cop with a gun, and he shoots you, NO ONE HAS A PROBLEM WITH THAT.
The cases people are upset about are the ones where the cop stopped a black person for a petty offense, and it ended up in a shooting or death.
And usually the cop involved has a whole record of bad behavior and mysteriously was still on the job.
Case in point. Derek Chauvin had 18 complaints of excessive force, and not only was he still a cop, but they had him out training other cops.
Garrett Rolfe had 12 previous incidents, including a previous shooting, and a case where he shot a suspect, collapsing his lung, and lied about the incident.
Jason Van Dyke (Shot Laquan McDonald 16 times) had 20 previous incidents, including one where he broke a suspect's shoulder, and he was still on the job. They even promoted him to a crime response unit.
Timothy Loehmann (shot Tamir Rice for playing with a toy) was fired from another police department for mental instability.