Bandits En Automobile
While writers often claim The Musketeers of Pig Alley (released 6 months after this) established the gangster film genre, this short film racks up two cop killings, a carjacking, two bank robberies, a car chase/shootout, and synchronized shooting in stylish long coats (late 1980s HK film-style). Films don't get more gangster than this.
Two episodes provide a contemporary account of the bold anarchist bank robbers that newspapers eventually dubbed the 'Bonnot Gang' (who were credited with the first use of the 'getaway car' - although it was used in the film The Bold Bank Robbery seven years earlier). The two episodes were later released together as Bandits En Automobile.
For a fascinating detailed discussion of the film's context, shooting locations, and comparison with both the historical events and a 1968 film on those events, see The Cine-Tourist.
For the story of the Bonnot Gang from the perspective of the bank they robbed (twice), see this Societe Generale piece.
For the story of the Bonnot Gang from the perspective of a renown anarcho-communist activist, see this libcom.org article.