During one weekend in 2008, 37 people were shot in Chicago, seven of them fatally. It was the year Chicago became a posterchild city of America’s gang problem.

The Interrupters, which is being shown at film festivals now and coming to FRONTLINE in early 2012, follows the inner workings of CeaseFire, an innovative Chicago program in which a group of older former gang leaders try to “interrupt” shootings and protect their communities from the violence they once committed.

In a review of the film published Friday, Slate’s Dana Stevens called it “the most necessary film of the year”:

“This is also one of the most engaging films you’ll see this year, full of vibrant, complex real-life characters whose troubles and joys will stay with you long after the movie’s done.”

The New York Times — which also also profiled CeaseFire’s work back in 2008 — reviewed the film as “a face to a raging epidemic and an unforgivable American tragedy.”

The film is scheduled to broadcast on FRONTLINE this February.