What happens to Tom after he is found guilty?

As expected, Tom Robinson is found guilty of the rape and assault of Mayella Ewell. It's a blatant miscarriage of justice, but it's the kind of thing that happened to many African Americans at that time in a society mired deep in racial prejudice. There'll be an appeal, but the sentence to be handed down is likely going to be the ultimate penalty: death. But even if Tom is spared the death penalty, he could still end up being summarily lynched. Whichever way Tom looks, it seems that there's no way out.
Tom's already seen white man's justice at first hand, so not surprisingly, he doesn't have much faith in the criminal justice system. Atticus will file an appeal, but Tom must know deep down that there's virtually no chance of the court's verdict being overturned. This explains why he makes a desperate bid for freedom from the prison where he's been remanded awaiting final sentencing. This is his last chance on earth to take his fate in his own hands. But his attempted escape is suicidal. He's gunned down by prison guards, shot seventeen times as Atticus tells Calpurnia later. There was really no need for the guards to shoot Tom that many times; it was pure overkill. Their excessive use of force is one final act of injustice, one last brutal expression of bigotry and racial hatred towards Tom Robinson.