There's a confluence of at least a couple of factors here. The mainstream media has spent decades telling white men that black men are bigger, tougher, and more aggressive, than all other men, and that in order to handle black men they need to be tougher. Now couple that mindset with white men ( and other men too) who join the police to reinforce their masculinity and you automatically have a bad combination.

Introduce guns to the meeting and you're sure to get fatal shooting from that. It isn't all just cops hating black men. I think part of it has to do with our country's ideas of masculinity and who is tougher than who.

You can see some of that in how cops simply talk to and about black men versus those they don't consider threats. White people have been taught for nearly a hundred years that black men are threats who can only be brought to heel with a firm hand.