Reviews of President Park Geun-hye’s selection of senior prosecutor Chae Dong-wook as nominee for the post of prosecutor-general are favorable, with commentators giving him high marks for not compromising his principles in investigating politically sensitive cases. Yet, he has to prove his mettle in the face of strong public demand for reform in the prosecution.

Chae’s nomination on Friday came three months after Prosecutor-General Han Sang-dae resigned from his post in disgrace. Han quit when his reform proposal was challenged by one of his subordinates. The chief of the Central Investigation Department in the Supreme Prosecutors Office voiced his opposition in public to a plan to abolish his department as part of the proposed reform.

The dispute over the fate of the department, which conducts investigations into cases involving politicians, business tycoons and other criminal suspects of high social status, turned ugly as it intensified. Han and the department chief had no other choice than to resign.

Still on the table is the plan to disband the department, which has often been accused in the past of being biased in its investigations in favor of the president, members of the ruling party and other powerful figures. Abolishing the department was one of Park’s election promises. She also pledged to create a separate office empowered to investigate criminal cases involving members of the first family and their relatives, make it possible for independent counsels to start investigations anytime and make a deep cut in the number of the vice ministerial-level posts in the prosecution.

Pressure to scale down the prosecution power is also coming from the National Police Agency, which demands a greater leeway in conducting criminal investigations on its own. Public opinion is on the agency’s side. As if to prove its demands are legitimate, the agency is currently investigating an allegation that a prosecutor did not look into a corruption case involving two of the prosecution’s investigators.

It is not just the proposal for sweeping reform that is demoralizing the prosecution. It has been afflicted by corruption cases involving senior prosecutors and a scandal involving a junior prosecutor, who had sex with a criminal suspect.

Pending the parliamentary approval of his nomination, Chae will have to ensure that reform proceeds without a hitch and do the difficult job of keeping the prosecution’s morale high in what promises to a painful period of transition.