Third Person (Limited Omniscient)
Our narrator is nameless and faceless, but s/he knows quite a lot when it comes to our characters.
Description of events and plot goes far beyond just the facts and figures. When Roy approaches Beatrice at lunch, our narrator not only gives us word-for-word dialogue between Roy and Beatrice, but we also get backstage passes to how he feels (which is nervous...because duh, he's confronting Beatrice the Bear).
The narrator also tends to be biased towards whichever characters the story is focusing on at the time. How so? When Delinko meets Chuck Muckle, he is described as a "silver-haired man" who was "vice-president of something-or-other for Mother Paula's" (19.48-49).
But when it's Roy's turn to describe Chuck, we're told he's "a snooty-looking guy with silver hair and dorky sunglasses" (20.9).
It's almost like three separates stories (of Roy, Delinko, and Curly) are all interwoven together. During the scene where Roy tricks Dana into chasing after him, we know that Dana plans to sneak onto the construction site to steal some cigarettes. So when Curly catches a kid in the rat traps he set out on the property, we can make an educated guess that it's Dana, despite the boy claiming to be Roy (and the narrator withholding any extra details). It's only when Delinko arrives that it's confirmed the boy isn't Roy.
But we already knew that.