Who is Wu Xiaoming from Death of a Red Heroine and what is their importance?

Wu Xiaoming is identified as the killer fairly early in the investigation. Chen and Yu have little doubt that they have found their man. He is an HCC, the son of an important Communist Party official. Wu is a decadent, ambitious hedonist with a cruel streak. He is a serial seducer, using his position as a photographer to win over women and use them until he is done with them. Wu takes obscene photographs of the women he seduces to blackmail them into silence when he wants rid of them. Wu has no respect for women, seeing them as sexual objects. He is married, although his wife is bedridden.