French critics have coined and used the expression film noir and série noire for the American movies that came in after the war had ended for France in 1944. The French themselves had and continued a tradition of the film noir: Jacques Becker, Marcel Carné, Henri-Georges Clouzot, Jules Dassin, Julien Duvivier, Melville, others, and later Nouvelle Vague directors Godard, Malle and Truffaut.
Un flic (1972) is Jean-Pierre Melville's (1917-1973) last film, preceded by the perhaps better known Le samouraï (1967) and Le cercle rouge (1970), and holds his equal. Alain Delon, once more, this time the key figure, as a detective inspector of police. Not much of a talker, but alert, a good shot, occasionally dishing out some physical treatment. Delon, counter to Catherine Deneuve, is a good and versatile actor, while Miss Deneuve is just beautiful and mainly acts through her eyelashes.
Then the gangsters, a lot of well-known French actors, with a core group of four, plus a night-club owner, and a female transvestite colleague of Miss Deneuve, all actually in it together. Delon only realises the full extent of the network at the end. The film nicely contrasts the routine night patrols of the detective (and his second), who are on call, and the longer rhythm of the preparation of coups by the gangsters.
There are two such coups in the film: One, on a bank in Western France. Quite an intricate coup, but the bank robbery has one of the gangster wounded through a lung shot. He needs hospitalisation, and an evacuation attempt by the gangster remains unsuccessful. The second is a helicopter/train(roof) theft, with some extraordinary camera work. This time, the chief gangster is caught, and - well, he talks. He is eventually shot by the inspector at a handover of loot going foul.
PS Ginette Vincendeau, a French film academic and writer, has written a seminal study - Jean-Pierre Melville: An American in Paris - which is reviewed by LGwriter as Trenchant study of Melville (June 14, 2004) on amazon.com (ie US). Very helpful, both.