https://screenrant.com/stranger-on-the-third-floor-first-film-noir-factoid/

The increasingly silly approach to "origin theories" of film noir will continue to be a source of confusion and error going forward--and this "essay" (more of a sketch, as is increasingly the case on sites such as this) will just help to perpetuate it.

No question that STRANGER puts noir elements into copious play a year ahead of THE MALTESE FALCON, but the author's American bias is just as copiously on display. And when confronted with the notion that 1939 French films such as LE JOUR SE LEVE and LE DERNIER TOURNANT are brimming with noir elements even before Boris Ingster did so, the likely response will be to shove these two films into that nebulous category known as "poetic realism."

Of course, this must stop at some point, especially when confronted with the solid evidence available to us that film noir begins in the early 1930s when a series of directors emigrated/returned to France, joining Jean Renoir and spearheading the creation of four films in 1932--LA NUIT DU CARREFOUR (Renoir), AU NOM DE LA LOI (Maurice Tourneur, returning, ironically enough, from Hollywood), COEUR DE LILAS (Anatole Litvak, emigrating from Russia), and TUMULTES (Robert Siodmak, shifting from the increasingly tense cultural/political situation in Germany).

All of these directors (save for Tourneur, whose son Jacques would become his proxy) would wind up in Hollywood, where they would variously contribute to the expanded range of American film noir in the 1940s. But these four are the ones present at the actual creation of the "crime film filled with conflicts of interest"--a good shorthand definition for the type of film that would become an integral area in film history.