have words for the cruelty and mindlessness that seems so prevalent this last several years.

There's still a lot wrong with the world, but by most objective measures other than population things are improving.

I believe that some "things" are improving, but I am not sure whether hooliganism is lessening or increasing. Presumably your post is referring to that, so I would appreciate seeing the evidence.

Murder is the crime the OP is about. 'Hooliganism' is not a specific thing. The word does not mean 'juvenile crime'. Juvenile arrests are at the lowest since the 1980's.
What do you even mean by 'hooliganism'?

Sad all the way around.

"Boys being boys" is evidently somewhat less outrage-inducing.

is protesting the death:

http://stlouis.cbslocal.com/2014/11/30/man-beaten-to-death-with-hammer-in-st-louis/

The Bosnian community wants this man's death declared a hate crime.

Or because the attackers and the victim were different races? Is being a different nationality grounds by itself for a hate crime charge?

Because he was white and maybe because was was Bosnian. You certainly couldn't tell his ethnicity just by looking at him, although location might have been a giveaway.

So, these guys just walk around with hammers and start banging on any car occupied by a man and woman for fun?

And kill the man when he objects?

Meanwhile most have this story on snooze. Political nightmare for the Ferguson protest crowd.