Die Morder Sind Unter Uns (aka The Murderers Are Among Us) (1946)

It's 1945 Berlin immediately after WWII. A young woman (Hildegard Knef) returning from a concentration camp finds her old apartment occupied by a former Army doctor (Ernst Wilhem Borchert) suffering from post traumatic stress disorder. Written and directed by Wolfgang Staudte, this was one of the very first films made in Germany following WWII. It's also an important film because it addresses the question of German guilt over the war. It rings with authenticity precisely because it is made by a German film maker rather than one of the victorious allies. Literally filmed in the rubble that was Berlin following the end of the war, this is rather crude film making but it lends an air of documentary like realism to the proceedings. Staudte was turned down by the Americans and the French for permission to film so he turned to the Soviets, who granted permission if he changed the film's ending which he did (Borchert does not complete his act of revenge which he did the original script). With Arno Paulsen and Robert Forsch.