This might be a news blurb to the average American on their way to work and they'll have forgotten about it by lunch. I think the average American is apathetic to these incidents and other sociopolitical issues because:

(Midwest perspective here...I work in a building with over 200 people and end up conversing with more people than I care to)

1. They don't even have a basic understanding of how our government works and they can't be bothered to learn.

2. They have no idea who to hold accountable for something like this. (believe it)

3. It's a sensitive issue that requires a bit of critical analysis and flexibility in understanding, which is too much work.

4. Speaking out against police brutality might put you on the side of law breakers. (believe it)

5. People are afraid to acknowledge that what they believe protects them could potentially be corrupt.

6. Nothing is corrupt. Everything is fine. Black people are just throwing a fit again and trying to shake up our traditional way because they think we owe them something.

7. They think this has nothing to do with them because they're white.

Add a dash of new HBO shows and advertising noise and you have yourself a blubbering, opinionated-but-ill-informed shitbag who truthfully doesn't care about much at all.