The Moon in the Gutter (1983)

In Marseilles, a woman commits suicide after she is raped in an alley. Nightly, her brother Gerard broods at the scene hoping to catch the rapist. He lives with his lover Bella whom he neglects, an alcoholic brother who lurks about, and his father who's stayed drunk since the daughter's death, ignoring work and his own companion. At a seedy bar, Gerard meets a wealthy, nihilistic hedonist and his beautiful sister. Gerard flips for her and thinks she's his ticket out of the slum. Bella warns him otherwise and also, in jealousy, sets two thugs on him. Then Gerard thinks he's found his sister's rapist. These emotional crises force Gerard to choose what's most important.