What's situation in the collard patch

As the children were escaping through the collard patch, Mr Nathan Radley shot his gun to frighten the trespassers. When the story came out, it went like this.....

"What happened?" asked Jem.

"Mr. Radley shot at a Negro in his collard patch."

"Oh. Did he hit him?"

"No," said Miss Stephanie. "Shot in the air. Scared him pale,

though. Says if anybody sees a white nigger around, that's the one.

Says he's got the other barrel waitin' for the next sound he hears

in that patch, an' next time he won't aim high, be it dog, nigger, or-

Jem Finch!"

Mr Radley knew exactly who he was talking about but used offensive language. His language was intentional; his prejuduce was racial; his language a racial slur.