Underclassman (2005)

Thanks to his boyish appearance, young cop Tre Stokes (Nick Cannon) scores an undercover assignment at a California high school in order to break up a stolen-car ring. Although Tre is on the good side of his superior, Capt. Delgado (Cheech Marin), he still has his work cut out for him, since the criminal ties at the school go deeper than he expected. While Tre's new friend, Rob (Shawn Ashmore), is involved in the thefts, he must figure out the identity of the person behind the whole operation.