After his medical studies in the same city, Selpin worked as a dancer, boxer, librarian, and art seller before he obtained, in the mid-1920s, an internship at the UFA film studios.
Selpin was subsequently employed by the European subsidiary of the Fox Film Corporation, where he held several positions, including – in 1927 – that of director's assistant to Walther Ruttmann on the set of Berlin: Sinfonie einer Großstadt.
In 1942, on the set of Titanic, after having experienced many time-consuming problems caused by drunk German sailors and soldiers acting as extras for the film, Selpin made several remarks critical of the military.
He was denounced for these remarks by Zerlett-Olfenius, once his personal friend, and, upon failing to retract his statements during a meeting with Joseph Goebbels, was arrested on 31 July 1942.
[2] According to the rumor, around midnight on 31 July – 1 August 1942, two guards entered Selpin's cell: and hanged him from the bars of a ceiling window, using his trouser suspenders as a noose.
[2]Despite Goebbels's attempt to conceal the truth, Selpin's brutal death quickly spread to Berlin's film colony who were deeply angered at Zerlett-Olfenius.