Who is Commissar Zhang Zhiqiang from Death of a Red Heroine and what is their importance?

Commissar Zhang Zhiqiang, a Communist official, is described as set in his ways. His thinking is rigid and predictable. When Zhang is appointed adviser to Chen's unit, he insists on painstakingly following dead end leads and politicizing the case. Zhang's first thought is always the good of the Party, thoughts that are now outdated and even harmful.