How was Darnell Houston able to help Walter’s case?

Hello, I can give you some summarys but i dont know if it wold help so

Explanation: Shortly after Herbert’s execution, Stevenson visits death row to catch up with several new clients, including Walter. Afterward, he travels to Monroeville to meet Walter’s large extended family. Gathered together in a small trailer, they passionately explain to Stevenson their indignation at Walter’s conviction, particularly when they were all with him at the time of the murder. Stevenson writes that the family’s hums of agreement were the kind of “wordless testimony of struggle and anguish” he heard “all the time growing up in a rural black church.” Walter’s sister Armelia expresses that the court’s dismissal of Walter’s alibi makes her feel that she has been “convicted too.” A debate arises about whether or not Walter, whom they call “Johnny D”, even needed an alibi, given his upstanding character.

as much wood as a woodchuck could chuck if a woodchuck could chuck wood.

sadly it cannot chuck wood