After watching the classic thriller M (1931), directed by Fritz Lang, I wanted to see the 1951 Hollywood noir version, directed by Joseph Losey, starring David Wayne, Howard Da Silva and Luther Adler. I wasn't disappointed at all, although I preferred the original for its, well, for its originality—Lang experimented with sound and shadow and camera angles and movement and tobacco smoke and silence and a bunch of techniques which were new to cinema at the time. Watching Losey's M (and the stories are similar), I kept comparing the performances of the actors playing the villain, a serial killer who preys on children, and may or may not have been based on The Vampire of Düsseldorf.
In both films we're introduced to the killer at the beginning, but we're not shown his face. The directors did this, I imagine, so the audience could get a sense of the frustration the onscreen public felt at being unable to capture or identify the psychopath, and for suspense, and likely to suggest the killer could be anyone (Inspector Carney (1951 version): We keep on picking up bums and the guy we're looking for could be a professor, a storekeeper, maybe even a cop. We look for him in honky tonks and he might be on a golf course.)
While both films are effective in making the villain appear anonymous at first, the latter version prolongs his facelessness, unnecessarily so, I'd say, since we get the idea long before his face is revealed. The Losey version, however, is creepier at the beginning (the first sequence begins while the opening titles are shown, which I think was uncommon, as title sequences were generally superimposed over a blank background).
Both films can be divided into three parts: (1) the killer kills and public anxiety becomes feverish; (2) the police, feeling the pressure, change their tactics, while organized criminals resolve to catch the killer on their own (to take the heat off their operations); and (3) the killer is pursued and captured, by the criminals, and he must now face a kangaroo court.
In the original, which had an ending that made more sense (without anything like the 1951 Hollywood twist sparked off by the pull of a trigger), the killer screams, "I can't help myself! I haven't any control over this evil thing that's inside of me! The fire, the voices, the torment!” As those judging him are criminals themselves, albeit a breed apart, the scene is compelling, and viewers might find themselves torn between rooting for a lynching and hoping the law intervenes.
Finally, the better bad guy, in my opinion: Peter Lorre as Hans Beckert (pictured below) in the 1931 version. His agape eyes and perturbed childlike face added to his convincing performance of a psychopath.
Peter Lorre as Hans Beckert (M, 1931)