What should I do if I find out that Dahao is a policeman?

According to relevant information, "in case" because Tian Feng found "Du Dahao". In "Chasing the Murder at the French Open", Du Dahao's identity is a deep undercover policeman, and only Tian Feng knows Du Dahao's true identity. Tian Feng played a key role in the discovery of Du Dahao, because the undercover identity is highly confidential within the public security department.