Deas, an area farmer who is white is an ardent defender of his employee, Tom Robinson, nearly getting himself thrown out of the courtroom when he stands up during the trial and hollers to the judge that he's never had any trouble from Robinson during all the years Robinson has worked for him. After the trial, and Tom's conviction, Deas feels "right bad about the way things turned out" and offers Helen, Tom's wife, a job working for him, even though he doesn't actually need the help. When he finds out Bob Ewell has been harassing Helen on her way to work, he finds Ewell an explains to him in no uncertain terms that if Ewell continues to harass Helen, Deas will make certain that he suffers the consequences. Ewell does not bother Helen again.
Mr. Link Deas is the employer of Tom Robinson, a coloured man who is convicted in charge of raping a white woman. He is one of the few people in Maycomb's white community who believes in Tom Robinson's account of events. He vouches for Tom's honesty and integrity in front of the whole court:
I just want the whole lot of you to know one thing right now. That boy's worked for me eight years an' I ain't had a peck o'trouble outta him. Not a speck.
Even after Tom's death Mr. Link Deas went out of his way to help his family to cope after his death. He employed Tom's wife Helen even though he did not particularly need her on his farm, but he did it to help her run the family. He openly declared in a racially hostile environment that he felt bad for her and the way circumstances had cruelly turned against her. When he realized that Helen was being persecuted and tormented by the Ewells who threw stuff at her, and forced her to avoid the public road and take a longer route to the farm, he walked her home and also threatened Ewell against persecuting Helen any further:
If I hear one more peep outta my girl Helen about not bein' able to walk this road I'll have you in jail before sundown!
So, in a way Mr. Link Deas takes the safety and security including financial security of the Robinsons under his wing.