For what it’s worth, black men kill more cops than cops kill unarmed black men.
Regarding your second claim, I can't find those numbers. The closest thing I can find is this newsweek piece [2] with data from 2013 and 2014. That suggests most people who kill police are white. But it also includes prison guards as police.
[1]: https://www.latimes.com/science/story/2019-08-15/police-shoo...
[2]: https://www.newsweek.com/who-kills-police-officers-315701