What is the dominant point of view in the story "The Catbird Seat" by James Thurber? Why?

Although not a first-person narrative, "The Catbird Seat" is told from the point of view of Erwin Marin, the protagonist of the short story. It is done primarily because he is the man who has concocted the plan to kill his nemesis, Ulgine Barrows. We find that Martin has been planning his murder for a week, and the story picks up on the night that he plans to commit the act. We also get expository information concerning Barrows' hiring and her tumultuos stay with the company. If the narrator had told the story from another character's point of view, the reader would know little or nothing about the prospective murder plans. Ms. Barrows was certainly unaware of Martin's plan until he appeared at her apartment. At that point, Martin's plan changed, and he decided to sandbag her instead of killing her.