Having had the justice system of Maycomb County fail him at the trial despite Atticus's proving him incapable of making the marks upon Mayella, Tom Robinson has no faith in an appeal, even though Atticus has encouraged him to be patient and trust him. For, there are simply too many other factors in the his environment which cause him to be mistrustful and terrified:
- The Jim Crow Laws are still in effect; he is marginalized by society
- The jury for an appeal trial will again be 12 white men
- The mob came for him once before; they may well come and lynch him now--or worse (burning, beating, torture, etc.)
- He has probably known of other men like himself who were falsely accused, yet were beaten or killed.
- He may feel like a caged animal and suffer from tremendous stress as he imagines what can befall him.
- He may have completely despaired, thinking his only chance is flight.