Here’s a detailed study from the National Academy of Sciences that concluded that death by police of black men (especially young ones) is pretty high. The article is pretty long, and I have no idea how accurate it may or not be.
https://www.pnas.org/content/116/34/16793
Sure it is because you have more black criminals percentage wise of the black population. Black men are about 5% of the population and they commit about 50% of all murders.
So I agree they have a higher rate vis a vis white men. BUT, that is a long way from the 6th leading cause of death.