Kevin McClain is the number one suspect out of anyone at St. Bernadine's from the get-go, and is the reason why Sam and Peter find out about the Turd Burglar at all — the school's police officer coerces Kevin into giving a false confession and he's expelled. His childhood friend, Chloe, reaches out to the documentarians so they can investigate the crimes and get him justice.
Kevin — who a classmate describes as someone who's constantly "doing an impression of a smart guy" — is introduced as an odd-ball who gets bullied for his extreme passion for "teas around the world," his unique taste in music, and for being the school's Fruit Ninja (people record themselves randomly throwing fruit at him in the hallways to see if he'll be able to karate chop it away in time) (again: this show won a Peabody). Between his status as a bit of a weirdo and his lack of friends, he seems to have plenty of motive. But is he the true Turd Burglar? Nope.
Kevin is a victim of the catfishing scheme too, but not in the way DeMarcus, Jenna, or Mr. Gesualdi are. Brooke begins an online relationship with Kevin that gets so serious that she's able to convince him to poison the cafeteria's lemonade without needing naked photos to use as blackmail. He willingly does it to impress Brooke, but when he goes to a motel to meet up with her (armed with around 30 boxes of condoms, FYI), she never shows and he realises he was played. Who is Brooke Wheeler, really?