Who is the narrator, can she or he read minds, and, more importantly, can we trust her or him?
Third Person Omniscient
Bernard Malamud narrates The Assistant in the Third Person Omniscient voice, entering in and out of his characters' hearts and heads. For most of the novel he keeps to the perspectives of Morris, Ida, Helen, and Frank, but on occasion he'll relate the point of view of others.
For example, when Ward Minogue breaks into the Karps' liquor store and burns it to the ground, the narrator tells us that Ward is thinking that "if he could get a couple of swigs past the nausea he would feel better."
This narrative technique allows Malamud to create several atmospheres, so to speak. We see events unfolding on the surface, but we also get below what the senses reveal. We live in the loneliness and anguish the people in this world experience.