Stefan Mavrodin attended rigorous training sessions with a specialist in aikido for the fight scenes in the movie. He also trained for several days in gun handling.
Filming lasted 10 days.
For the preparation of his role, Stefan Mavrodin (the assassin) spend days training in facial expressions, gestures and even movement. He had to move, turn and run perfectly, without any extra movement because his character was highly trained in crowd infiltrations. He also trained in close combat and gun handling with an expert.
The intro of the movie and the scene where the assassin kills his first target were the first scenes filmed. The rest of the movie was filmed in sequence.
The large room for the Echo Club scene took almost 2 weeks to be prepared. There used to be a restaurant which served for the hotel and when the movie was in production the building was already abandoned for some years so the hall needed to be cleaned out.