KARL: I can help you tote it if I don't give out first.
A murderer is let out of a mental institution. He comes along a young boy, walking alone. In a different movie, this would be the beginning of another grisly crime. But in Sling Blade, it's the beginning of a beautiful friendship.
FRANK: If you wanna play, you can come on over, because we ain't no good either.
We don't know Karl's history at this point, so it seems like he and Frank are making friends. They are becoming friends, but it might be more like Frank is the younger brother who Karl never had.
FRANK: I won't tell her about you being in the state hospital for killing.
Hey, you know you can trust someone who keeps your criminal record a secret from his mother.
FRANK: I like the way you talk.
KARL: Well, I like the way you talk.
This is a funny exchange, and it shows us how comfortable Frank and Karl have grown with each other. They accept one another for differences that other people might find weird or off-putting.
FRANK: Last time, you got mad and run Morris and them off. Told them to stay away from here.
DOYLE: That ain't none of your business, Frank. Besides, that's the way friends do one another.
We're not sure Doyle knows what friendship actually means. Most people don't run their friends out of the house and tell them to never come back. But what kind of friends actually come back the way these people do?
DOYLE: We don't got no goddamn band! We don't need to f***ing practice, Randy! And we don't need a s***-ass manager neither! You motherf***ers! Y'all just a bunch of losers! I'm the only sane son-of-a-b**** here! Get the f*** out of my house, now!
Doyle doesn't have any friends, because he's a terrible person. But maybe he's a terrible person because he doesn't have any real friends? It's a confusing cycle, a chicken-or-the-egg situation involving abuse and sadness.
KARL: I'm tired too. Just 'cause I ain't gonna be around no more, maybe that don't mean I don't care for you. I care for you a good deal. I care for you more than anything else they is. You and me made friends right off the bat. […] It don't make no difference where I was to be. We'll always be friends. Can't nobody stop that.
This is Karl's way of saying goodbye to Frank. Is he being a good friend to Frank by killing Doyle? Or would he be a better friend to Frank if he stayed by his side literally, instead of with all this metaphorical "we'll always be friends" stuff?