Extraordinary Mission

A cop was going through a rough path in his life: his mother passed away recently, while he was under investigation for bribery. On his way to the funeral, he hit someone with his car. Panicked, he decided to get away with it under camouflage. Days passed; when it finally settled down, he found out that the criminal he is chasing after now is the one he hit. What's worse, someone witnessed the whole accident, and filed an anonymous report. That "someone" is also a cop. What's his purpose? Why is he after this accident? A very complicated story lies beneath.