“There is one motif used in this case that seems to illustrate particularly well how fantastic real events have become: the idea that the criminal caste, Berlin’s underworld, would take to the streets of its own initiative to seek out the unknown murderer so as to evade greater police activity is taken from a factual newspaper report and seemed to me such compelling cinematic material that I was constantly living in fear of someone else exploiting this idea before me.”
- Fritz Lang, ‘My Film M: A Factual Report’