Just 6.5 (2019) on Netflix

Plot summary

Addiction has spread across Tehran, and the man the police cannot reach is Naser Khakzad, a kingpin who keeps out of sight. Samad, a narcotics detective, works the case with his colleague Hamid, scouring the city's streets and disrupting an overcrowded prison in his hunt for the man. He has heard the lies of enough dealers that his patience has worn thin, and his methods are rough and often dubious. Samad believes that an arrest at the top will help bring the problem under control. A raid captures a minor dealer, and from there the officers follow a chain toward a bigger figure connected to Khakzad.