Who is Child Welfare People from Invisible Monsters and what is their importance?

After Shane McFarland suffers burns to his face, the child welfare department becomes involved. The child welfare people believe that Shane was abused by his father and that abuse, not the accident with a hairspray can, is the cause of the burns. Shane insists that the burns were an accident, as do his parents, but the welfare people continue to get phone calls insisting that something is not right in the McFarland home. Later it is revealed that these calls came from Shannon. Eventually, the child welfare people decide that there is no abuse taking place in the McFarland home and drop the case. However, soon after, Shane is visited by a police officer who claims to be making a follow-up report on the case. This cop forces Shane to commit sexual acts with him, introducing Shane to the homosexual world. Later, the reader learns that this cop is Manus Kelley.