Who killed Zhiyou's father in my name?

In My Name, Zhiyou's father was killed by boss Cui. Zhiyou's father and boss Cui were good friends before his death, but his real identity was a policeman. He came to organize undercover. Boss Cui felt cheated when he found out, so he killed Zhiyou's father.

The boss Cui is the boss of the gang's drug trafficking organization, and the police have been eyeing them for a long time. However, Boss Cui is very cautious and people can't catch the evidence, so the police sent Zhiyou's father to go undercover. Zhiyou's father successfully broke into the organization and became good brothers with Boss Cui, but it also put Zhiyou's father in a dangerous situation. Later, the identity of Zhiyou's father was exposed. For the safety of herself and her daughter, Zhiyou's father and daughter are temporarily separated and have been hiding in the dark.

However, on Zhiyou's birthday, Zhiyou called his father and cried. Zhiyou's father was very distressed by his daughter and decided to venture home. As a result, when Zhiyou's father was about to enter the house, Boss Cui appeared and shot Zhiyou's father. Because boss Cui wore a hat and was well hidden, Zhiyou didn't see who killed his father, so at first she didn't know that boss Cui was her father-killer.