“MP”. He is a former Navy MP who drinks Heinekens (and keeps a log of how many he drinks in a journal) and beats on Gately’s mother between her groin and her breast so that none of the bruises shows. He never lays a hand on Gately, though Gately is terribly afraid of him regardless. When the beatings happen, Gately pretends that they aren’t happening and simply turns the television up louder, rather than intervening (which he could have considering Gately is actually stronger than MP (who had taught Gately how to lift weights)). During the summers, MP would kill flies methodically by injuring them and pulling off their wings. He claims this is beneficial because their tiny cries keep other flies away. What disturbs Gately about this is that he never tries to put the flies out of their misery once MP passes out. He allows the flies to suffer, too.
Pakistani MD at Our Lady of Solace Hospital
He is the MD who tells Don Gately about his mother’s cirrhotic hemorrhage and how she now has the neurologic level of Brussels sprout.