Yann Demange, director of the under-seen Northern Irish thriller ’71, stays in period mode with White Boy Rick, a fact-based tale set in 1980s Detroit, convincingly portrayed by modern day Cleveland.

As Rick Wershe, a teenager recruited by the FBI to help bring down local kingpins with government ties, newcomer Richie Merritt shines bright and finds steady support through Demange’s gritty filmmaking as well as a surprising amount of humor for such a grim topic.

From luckless Rick Sr. (a mulleted Matthew McConaughey) insisting on taking his kids out for frozen custard to young Rick’s nonchalance with handguns in the presence of authority figures, dark comedy dots the fairly standard rise-and-fall drug dealer narrative before it devolves into the depressing “crime doesn’t pay” mode of Blow and other predictable brethren.

While it’s unclear why Rick agrees to cooperate with the FBI, other than the assumption that he has no choice, and the film is further cheapened by such wonky decisions as conveying Rick’s sister Dawn (Bel Powley, The Diary of a Teenage Girl) kicking addiction by finally having her dialogue be discernible, the story moves well enough and is fleshed out by an appealing supporting cast.

Jennifer Jason Leigh, Brian Tyree Henry (TV’s Atlanta), Rory Cochrane (Dazed and Confused), RJ Cyler (Me and Earl and the Dying Girl), Eddie Marsan, Bruce Dern and Piper Laurie make memorable marks in limited screen time, helping and hindering the Wershes’ dreams of a better life, but all are ultimately unable to save the film from genre clichés.

Grade: B-minus. Rated R. Now playing at AMC Classic, Biltmore Grande and Carolina Cinemark

(Photo: Columbia Pictures)