It's in Chapter 27 where Link Deas offers Tom's widow, Helen, a job. This shows us that not everyone in Maycomb is convinced of Tom's guilt. It also explains why Miss Maudie is so sanguine about the future of race relations in the town despite the monumental miscarriage of justice that has taken place. Though Link's giving Helen a job is motivated by guilt—which is seldom a good motivation for doing anything—his actions are still admirable in that they provide us with an example of someone refusing to stay in their lane in such a racially-segregated society. Whatever Link's motivations, he's done a good deed.

As for Heck Tate, he takes his role as Maycomb's sheriff very seriously indeed. That's why he gives a true and faithful account on the witness stand as to Mayella's injuries, even though he knows full well that it won't make much difference to the jury. Before the trial got underway, Heck also demonstrated his commitment to upholding law and order by warning Atticus in advance of a potential lynch-mob rumored to be about to descend on the jailhouse to kill Tom Robinson. It would've been all too easy for Heck to have stood to one side and allowed the lynch-mob to mete out summary justice to Tom there and then. But he didn't. He remained at his post and did what he could to diffuse the situation.