I really enjoyed this drama and don't understand a lot of the critiques people have. The cases are based on real-life murder cases. Googling a list of South Korean serial killers and reading up on them makes this clear very quickly. Of course, some things were changed but that is to be expected it is a drama, not a documentary. Going at it with this knowledge in mind the difference to most other dramas should become clear quickly. If you are interested in profiling and don't need a high-speed plot def go for this drama.
The cases are based on real-life murder cases. Googling a list of South Korean serial killers and reading up on them makes this clear very quickly. Of course, some things were changed but that is to be expected it is a drama, not a documentary. Going at it with this knowledge in mind the difference to most other dramas should become clear quickly. If you are interested in profiling and don't need a high-speed plot def go for this drama.