>>24808383
But the ultimate twist, after pushing the reader to think he's the killer, a the last act switches to 3rd person following the police investigation...

And they also come to the conclusion that he's the killer, and are frustrated at his denials to the point of screaming at him and hitting him. He had extensive notes on all his coworkers, on everyone he interacted with. On prostitutes he's gone to, on people who work at the stores around him so he knows which ones to avoid because they started to remember him.

Eventually they bring in an actual criminal psychologist who isn't freaked out by this guy's bizarre behaviour. And starts working backwards with the evidence to workout. and in the twist of the twist, it's... not actually him. He's just autistic