So today is not from a movie, but rather a television show. Perhaps the best damn television show of all time. THE WIRE.
This peice is from the start of the very first episode. Det. Jimmy McNulty has arrived on the scene of a murder and is talking to one of the witnesses.

Det. James ‘Jimmy’ McNulty: So your boy’s name was what?
Kid: Snot.
Det. James ‘Jimmy’ McNulty: Called the guy “Snot”?
Kid: Snot Boogie.
Det. James ‘Jimmy’ McNulty: God. Snot Boogie. He like the name?
Kid: What?
Det. James ‘Jimmy’ McNulty: Snot Boogie?
[the kid does not answer]
Det. James ‘Jimmy’ McNulty: This kid, whose mama went to the trouble to christen him Omar Isaiah Betts… You know, he forgets his jacket, his nose starts running and some asshole, instead of giving him a Kleenex, he calls him “Snot”. So he’s Snot forever. Doesn’t seem fair.
Kid: Life just be that way, I guess.
Det. James ‘Jimmy’ McNulty: So, who shot Snot?
Kid: I ain’t goin’ to no court… Mothafucka didn’t have to put no cap in him though.
Det. James ‘Jimmy’ McNulty: Definitely not.
Kid: He coulda just whooped his ass like we always whoop his ass.
Det. James ‘Jimmy’ McNulty: I agree with you.
Kid: He killed Snot. Snot been doing the same shit since I don’t know how long. You don’t kill a man over some bullshit. I’m sayin’, every Friday night in an alley behind the Cut Rate, we rollin’ bones, you know? I mean all them boys, we roll till late.
Det. James ‘Jimmy’ McNulty: Alley crap game, right?
Kid: Like every time, Snot, he’d fade a few shooters, play it out till the pot’s deep. Snatch and run.
Det. James ‘Jimmy’ McNulty: What, every time?
Kid: Couldn’t help hisself.
Det. James ‘Jimmy’ McNulty: Let me understand. Every Friday night, you and your boys are shootin? crap, right? And every Friday night, your pal Snot Boogie… he’d wait till there’s cash on the ground and he’d grab it and run away? You let him do that?
Kid: We’d catch him and beat his ass but ain’t nobody ever go past that.
Det. James ‘Jimmy’ McNulty: I’ve gotta ask you: if every time Snot Boogie would grab the money and run away… why’d you even let him in the game?
Kid: What?
Det. James ‘Jimmy’ McNulty: Well, if every time, Snot Boogie stole the money, why’d you let him play?
Kid: Got to. It’s America, man.