The film co-stars Janine Chang, Cheung Siu-fai, Josie Ho and Chin Kar-lok, who also served as an action choreographer.

Murderer is a co-production between Focus Features and EDKO Film, and was released theatrically in Hong Kong on 9 July 2009.

Ling (Aaron Kwok) is a married self-assured Police Chief Inspector with an adopted 5-year-old son who is investigating a cold-blooded serial murder case.

During the lockdown the central plot twist of the movie is unveiled, as Ling's adopted son confesses his real identity to him.

Ling is able to gather himself to kill the accomplice and is moments away from carrying out justice on his adopted son until the police arrive and shoot him.

The film marks the directorial debut of Roy Chow, and features action choreography by Chin Kar-lok.

Despite being shaken after performing the stunt, Cheung described his fall as intense and exciting: "Although I am afraid of heights I feel this scene is very refreshing and challenging.

This photo on the movie poster was taken by famed photographer Wing Shya, who aimed to capture Kwok's exhausted look and almost madly vicious eyes.