The very odd narrative focus of Patricio Pron's novel

So at the end of section 2 of Patricio Pron's My Fathers' Ghost is Climbing in the Rain we get teh full picture of the story of the man who disappeared from the small town or city -pop about 13k of 16k, sources vary - in northern Argentina, which, roughly, is this: Man who possibly had some degree of mental retardation is schoolmate friend of narrator's father; the man's sister was some time back involved in demonstrations against the tyrannous regime, and she is killed; years later, the man is paid government reparations for this loss, I think it was the equivalent of $56,000? His friends in town - he's somewhat of a loner with a small job and small income as a janitor and handyman at a town athletic or social club - encourage him to buy a house, which he does; then, having $ for the first time in his life, he gets involved with prostitutes and some rough trade in the many brothels in this remote part of the country. One of the women betrays him, tricks him into signed half the deed over to her - then she and some thugs kill the guy and drop him in a well. After a search of 10 days involving much of the local community, they find the body and arrest 4 people on murder charges. Narrator's father meticulously saved many clippings and notes about this event; the father spoke at the funeral and wrote an article himself. At the end of the section, the narrator - and we - understand why the father, dying in a nearby hospital, saved all this material. Not sure exactly, however, why it's all so important to the narrator - something about reading of his father's devotion to or at least interest in his childhood friend helps him feel closer to his father. Yet it is part of the oddity of this novel that the narrator has devoted a hundred pages or so to this sub-story and has invested in literally no description of the father and virtually nothing about the narrator and his relation to or interaction with father or with anyone else in the family - or for that matter, with any person. It is as if the narrator relates best, or only, to documents, records, papers - not to people. Perhaps this is a trait he shares with his father - or else it's part of his characterization as a disturbed person and an unreliable storyteller. But what makes him who he is? If there is some trauma or history of illness, we are not yet aware of it.