Le désordre et la nuit

When the middle-aged police inspector Georges Vallois (Jean Gabin) is assigned to investigate the murder case of a drug dealer, the suspect is his addicted mistress Lucky Fridel (Nadja Tiller). But soon Vallois and Lucky have a love affair and he believes she is innocent and needs rehab.

"Le désordre et la nuit", a.k.a. "The Night Affair", is a different film-noir. The storyline shows a dirty tale with an old police inspector having an affair with a junkie woman that could be his daughter and manipulating the events in the end to present the best solution for the case. My vote is seven.

Title (Brazil): "Vício Maldito" ("Damned Addiction")