Who killed his father's brother on the road?

A car full of drunk white men ran their father's brother down and sped off. 

They was coming down a hill and beneath them was a road that turned off from the highway. Well, your father's brother, being always kind of frisky, decided to run down this hill, and he did, with that guitar banging and clanging behind him, and he ran across the road, and he was making water behind a tree. And your father was sort of amused at him and he was still coming down the hill, kind of slow. Then he heard a car motor and that same minute his brother stepped from behind the tree, into the road, in the moonlight. And he started to cross the road. And your father started to run down the hill, he says he don't know why. This car was full of white men. They was all drunk, and when they seen your father's brother they let out a great whoop and holler and they aimed the car straight at him. They was having fun, they just wanted to scare him, the way they do sometimes, you know. But they was drunk. And I guess the boy, being drunk, too, and scared, kind of lost his head. By the time he jumped it was too late. Your father says he heard his brother scream when the car rolled over him, and he heard the wood of that guitar when it give, and he heard them strings go flying, and he heard them white men shouting, and the car kept on a-going and it ain't stopped till this day.