I'm not sure what you mean by 'Hong Kong police dramas' because you didn't provide any relevant information. However, according to my knowledge, if "Long Xiaotian" refers to the character name of a Hong Kong police film, it could be one of the following: Long Xiao Tian (2010): This is a police and bandit film directed by Hong Kong director Huang Wei Sheng, which tells the story of the struggle between the police and the bandits. The main character of the movie was a policeman named Long Xiaotian. Detective Records (2005): This is a police film directed by Hong Kong director Mak Siu-fai, which tells the story of the struggle between a policeman and a gang leader. The main character of the movie was also a policeman named "Long Xiaotian." Infernal Affairs (2002): This is a film directed by Hong Kong director Liu Weiqiang, which tells the story of the struggle between a policeman and an undercover gang. The main character of the movie was also a policeman named "Long Xiaotian." I hope the above information will be helpful to you.