South Korea’s ruling Democratic Party (DP) is pressing ahead with a reform meant to curb prosecutorial overreach even though recent police failures have raised doubts about whether its replacement system can protect victims when investigations go wrong.

The dispute centers on prosecutors’ supplementary investigative authority. Under Article 196 of the Criminal Procedure Act, prosecutors may conduct additional work on cases referred by the police as long as they do not change the essential identity of the alleged offense.

The DP’s July 9 billwould abolish that power and limit prosecutors to reviewing police files and ordering officers to take