This beginning also signals the importance of sound to the internal structure of the film, one of Germany’s first using the new technology. There is no non-diegetic music, something that would have been weird for a silent movie, much less one that could finally play back the same background music in synch in every cinema showing it. In fact, there are even stretches of the film that are fully devoid of any sound: no music, no speech, no effects. Those are quite eerie, certainly for a modern viewer not used to complete silence in films, especially when briefly broken by individual sound effects. The lack of non-diegetic music also accentuates every moment in which music is being heard, mainly in the form of whistling. Most prominently and famously, Hans Beckert, the killer, whistles a portion from Edvard Grieg’s Peer Gynt (1876) when in pursuit of his compulsion; while not heard in its entirety, only in broken segments, the full piece is played ever faster and more chaotic until its conclusion, a fitting melody for a man forced to kill by his inner demons.
—Spoilers about the plot have hidden below —
The importance of sound as opposed to sight plays a role in several scenes. We and his initial victim hear Beckert’s voice before we see his face, and we and him hear his hunter’s words reach his terrified face before he is captured. Beckert’s landlady, who is oblivious to his suspicious demeanour, is hard-of-hearing; the clue that sets the criminals on his tail comes from a blind man. The famous visual aid of the chalk M on Beckert’s shoulder, which the audience might expect to lead to his capture, is ultimately unnecessary (beyond providing one of several great moments of extreme tension).
He is not the only one to whistle. The others, probably not coincidentally, are the other two lead characters, as much as you can say that with this film: police detective Lohmann (a gregarious Otto Wernicke) and the top criminal known only as the Schränker (terrifyingly played by Gustaf Gründgens and whose role name google tells me means “safecracker”, though the film implies he’s done worse crimes than robbery). The situations in which they whistle (the Schränker uses whistling as a signal for others to help break into a building Beckert is hiding in; Lohmann uses it to unnerve a hoodlum whose papers he is inspecting) are brief and don’t have direct thematic significance, but they tie the three characters together. They also happen to occur at important structural moments: The police’s continued “harassment” of Berlin’s underworld in search of the serial killer prompts the criminals to look for the man themselves, setting in motion the rest of the film, and the Schränker’s whistling signals the beginning of the end for this endeavour.
The film is very carefully constructed, with lots of other parallels drawn between different people and groups of people. Beckert’s first victim (at least the first we see) is named Elsie Beckmann; the similarity in naming underscores Beckert’s behaviour, which is often like that of a child, like pulling faces in front of a mirror, and like a child he may not be responsible for all of his actions. After Elsie’s killing and before police and criminals start closing in on Beckert, he remains mostly off-screen for over half an hour. Writers Thea von Harbou and Fritz Lang instead dedicate considerable time to comparing how police and gangsters react to the situation. Both groups – and that the underworld is every bit as organised as law enforcement is highlighted a number of times – are very methodical.
The police examine the crime scenes, comb the city for possible witnesses, follow up on every tip by the populace, as well as analyse handwriting samples and try to get fingerprints from a letter sent to a newspaper. They also use more underhanded methods, like gathering intrusive medical information, investigating suspects’ homes under false pretences and, later, misleading a suspect/witness about a guardsman’s injuries to put pressure on him. It’s an interesting, clearly well-researched glimpse into then-current methods of policework.
Similarly, the criminals divide Berlin into sections and instruct all the beggars and panhandlers to keep a lookout and to report back to “headquarters”. Incidentally, the leaders of both groups (police and criminals) are clean-shaven, and both have an assistant or second-in-command with a mustache. The parallels are also emphasised by Lang crosscutting between the two groups.
There are also differences. While the police methods aren’t always morally above reproach, they are (or at least seem) perfectly legal, and it should be noted that the police do technically suss out Beckert’s identity first, even if their opponents catch him before they do, mainly by accident. Lohmann also doesn’t engage in vigilante justice, but ultimately hauls Beckert in front of a real court, whereas the Schränker tortures someone, dismisses the idea that murder in general is a bad thing and leaves little doubt that he intends Beckert to die regardless of what the law says. How much of this is eerily accurate prophesy and how much is an accident I don’t know, but the Schränker is very reminiscent of the later Gestapo agents in clothing, diction, bearing and attitudes, as well as Roland Freisler, though the film predates that man’s involvement in the Nazis’ sham “People’s Court”.
Despite being a child killer (possibly with a sexual component, though that is never explicitly stated), sympathy is shifted towards Beckert in the final part of the film, where he is hunted like an animal and brought before a kangaroo court that already knows the outcome of his “trial”. M is not a traditional thriller about a criminal being brought to justice by the forces of good. Instead, director Fritz Lang is more interested in painting a picture of a psychologically damaged man in damaged times, in which widespread disillusionment in the state has turned into mistrust, causing people to take matters of “justice” into their own hands. We see this atmosphere of suspicion throughout the film, with people falsely accused of being the murderer.
But we are also made to empathise with them. A man seen only from behind with a child next to him turns out to be a father walking her to school, but as long as we don’t know that, he might be Beckert. Later, we already hear his whistling as the camera follows a girl around a corner — where she is awaited by her mother, who whisks her to safety, oblivious to the killer’s proximity. Lang’s ratcheting-up of suspense is remarkable, and it lets the audience feel a little bit of the tension surely present in a city of a few million haunted by a kiler still at large. After all, the last word of the film is “Ihr” (you), spoken in front of a black screen.
Within the context of the film’s story, the M clearly stands for “Mörder” (murderer), but it might also stand for “Meute” (mob); note that the original poster as well as the title card it mostly replicates shows the hand that marks Beckert, not the murderer himself.
Notwithstanding the dark subject matter, there are occasional moments of humour in the film, like a short scene showing beggars dealing with the economic downturn, Lohmann’s reactions to a spelling error and, later, to the surprise reveal of the true purpose behind the Schränker’s break-in, as well as a criminal giving up his escape from a police raid (it’s funny in context). A funny scene in which a robber who has been forgotten by the Schränker complains about that to his “comrades” while being “rescued”, only to be confronted by waiting police officers, is turned into a moment of relief in the almost-last-scene, where the mob is stopped from lynching Beckert by the unexpected arrival of law enforcement.
In conclusion, and at the risk of using a probably well-worn, and regarding reviews of this film likely worn-out, phrase: the M stands for masterpiece.