Director Simon G. Mueller began preproduction of FATALIS in June of 2006. A total of four years and four months before the film was in its final format for film festival submission.
Originally, the film was to take place in Vienna, Austria. The brief cameo appearance of Jack Unterweger, an infamous prostitute strangler, is still in the NYC version which was originally part of the Austrian based screenplay.
Austrian film producer, Alfred Ninaus, planned to produce the film in 2008, but the production was put on hold due because of financing problems. Eventually, Simon G. Mueller decided to move the project to New York City. Simon used his own savings, along with the help of cinematographer Markus E. Mueller and co-writer Senad Halilbasic, to fund the production.
The Croatian dialogues were written and directed (uncredited) by assistant director Senad Halilbasic.
The American actors had to absorb a Croatian accent and underwent training classes with producer Diane M. Kolanovic.