He comes off as an asshole but I don't blame him.
Don't blame the kid at all.
Comments like this are just ridiculous. The kid is a dumbass. There are constructive ways to have your voice heard. Playing "Fuck tha Police" at a memorial for a cop murdered because of the uniform she was wearing is not one of them. What do you know about Miosotis Familia? Was she a racist oppressor? Maybe she became a cop because she wanted to work in and help her community.
Why not spend as much time advocating for constructive, positive solutions that build relationships between communities and the Police, instead of needless antagonism? You guys continue the cycle, and whether you like it or not the Police aren't going away any time soon. That doesn't mean calling out the Police when they're wrong and holding them to account, but that isn't what this is.