Dude gets shot in the back for suspicion to maybe have had a knife on him. 7 times

Guy walks by with an AK-47 or someshit on. The cops give him water bottles because he might be thirsty. He is also thanked.

So, water bottles for a guy with an actual, obvious, huge weapon on him, and 7 shots in the back for a guy who had the suspicion of having a knife on him.

What additional difference was there between both dudes?

This is where we are at.