The basic premise is simple, and so is the plot, but it unfolds step by step in a way that keeps the film nicely paced throughout its short running time. Basically it's about a gangster (played by Robert Hussein's stoic self) who, after being released from prison, seeks vengeance on his former best friend who he blames for his incarceration and who also appears to have taken off with his sister (Marie-France Pisier) while he served his sentence, a sister which the gangster probably loves a bit more than a brother should. As you can probably tell by the title 'La mort d'un tueur' (Death of a Killer) doesn't go for big surprises, instead it's the elegant and stylish manner in which this very familiar genre material is executed that takes center stage in this melancholic crime thriller.
I found it quite amazing in its simplicity because it provides so much clarity without requiring much dialogue. It probably won't rock anyone's world, there isn't really any substance to it and like me you'll probably have seen it all before but all the elements are put together to great effect and it's achieved on apparently a very small budget. Probably what IS remarkable is how very Leonesque the film is given that it was made before it could have possibly been influenced by Leone ('A Fistful of Dollars' came out later the same year), I had already found Hossein's "Exterminating Angel"/"Marienbad"/murder mystery mix 'Le jeu de la vérité' quite Leonesque and that film came out in 1961.
Also there are quite a few flashbacks that are more or less montages with music playing over them and employing voice-over narration instead of using the scenes' actual sounds and hearing the characters in the flashbacks speak which I can't really remember seeing in an earlier film than this one although I'm probably just not thinking hard enough. Anyway, it's pretty much a gangster flick with spaghetti western flair which is probably why I was often reminded of the films of the great Hong Kong action filmmaker Johnny To. If, like me, you are no stranger to the simple joys of watching three gangsters in suits walk in formation accompanied by cool jazzy music this little gem comes highly recommended to you.