many members of the cast and crew had worked with lang on his earlier films. rudolf klein-rogge returned to play dr. mabuse as he did in "dr. mabuse the gambler". klein-rogge acted in lang's earlier films including "destiny", "die nibelungen", "metropolis" and "spies". otto wernicke reprises his role as inspector lohmann from lang's "m". klaus pohl plays lohmann's assistant müller. pohl acted in lang's "woman in the moon" and in an uncredited role in "m".