Fully of action and surprising twists

This is my second time watching this drama, i remember the first time it left an impact with all the surprising twists. However now that i have rewatched this show i think some of the things just don't make sense like i know its fictional but the fact that some of the things could just never happen as there are rules within the police and to me the only main bad guys in the drama was the cops and prosecutors, people with power.

I did enjoy this drama though as I even rewatched it. wish there was a season 2 where we saw Shi Hyun get a happy ending.