It’s hard to find something new to express about this film, as so much has already been shared. This is a truly remarkable piece of German cinema history, among the finest productions created prior to World War II, and a highlight in the filmography of Fritz Lang—a director who would soon depart Germany because he wouldn't cooperate with the emerging Nazi government. The story draws from actual occurrences, specifically the crimes of Peter Kürten, known as the “Vampire of Düsseldorf,” whose actions instilled fear throughout the city and targeted young people. The movie effectively conveys the pervasive anxiety felt by residents and the efforts undertaken by law enforcement to locate this brutal criminal. The black-and-white cinematography displays traces of German Expressionism while maintaining the realism essential to the narrative. I’m unsure whether it influenced or was itself inspired by film noir, but there are clear parallels in its visual style. Peter Lorre delivers a standout performance; he embodies his character with incredible subtlety and impact, essentially acting without dialogue. It's an exceptional contribution from the actor and likely paved the way for future opportunities.

Source on TMDB