Not the best, there are many similar elements with the OG Criminal Minds.

I was hoping to see Joon-gi and Chae-won together :<.

I liked the drama but it disappointed me in so many way. I didn't see any development in the characters, the only one I really liked was the team manager Kang, because I saw some bad events happening to him so I felt sad for him, but the rest, I didn't like their teamwork. The cases were good but the along the episode it was solved quickly and I didn't feel any tension, but some had a good ending.

About the main story, [spoiler]The Reaper[/spoiler], it was forgotten in many episodes, the team acted like it never happened and in the end, it was solved easily.
Also the [spoiler]Nadeul River murder case[/spoiler] got me curious in the begining but in the end, it was only showed later in one episode and it ended, once again, quickly.

If there will be a second season, I'll watch it but I hope it will get better and cause some tension.