a. I'd hope that virtually all cops, regardless of race, gender or whatever, wouldn't outright murder a dude for the lulz and it was more a case of the ones involved with Floyd were simply horrible at their job and trash human beings.
b. The fact it's a question as to how specific demographics of cops would handle things when put in a situation like that probably says more about that organization as a whole and how a "I have a badge, so I can do whatever I want!" mentality is pervading it to a noticeable degree than anything else. Because from all the incidents that have been posted here and elsewhere concerning them escalating situations and using excessive force as a go-to really makes it look like my hope in "a" is a false hope.