Thanks to Marshall, the man who's been going around killing children in the neighborhood has finally been identified. It turns out that it's a man who works in a local store. When the police arrange for a line-up, Marshall is immediately able to identify a big, stocky man with red hair and blotchy red-brown freckles. He recognizes him as the stock boy from Schmitt's Variety Store. April remembers that she'd seen the man in the store. Back then, he'd seemed quite shy and quiet, but now in the police line-up he looks completely bewildered, as if he doesn't understand what's happening.
The next day it transpires that the man has confessed to all the crimes. This means there won't be a trial. And as he's clearly suffering from some kind of mental illness, he's been sent to a hospital for the criminally insane.
For years, Mr. Schmitt had let the young man work in his store, as he was his cousin and was willing to work for little money. He'd never been on the police's radar, because Mr. Schmitt always gave him an alibi. Suspicion then fell upon the Professor, whom everyone assumed was the neighborhood killer. But it was the stock boy all along, and now everyone's mightily relieved that he's been caught.