The series is more focused on the job of a profiler rather than the criminals. Normally, crime- thrillers provide their audience with thrill through their cat-mouse chase, where it seems difficult to catch the criminals and includes various efforts to do so. However, this one is different from the usual. This one is more of a way to make the audience familiarise with the job of profilers and their need in the society to catch the criminals , which is why it slowly progresses in that direction to make the viewers learn about that process from the scratch. It's more towards a maturer side rather than providing immense thrill.
Moreover, it will be more likeable to the people interested in knowing the 'criminal psychology' specifically rather than watching a criminal chase. Here, the investigation process and getting a confession out of the criminals through a mind war is the thrilling part rather than catching the criminals.

Also, this drama is significantly focused on the development of the leads as profilers since they didn't started with it originally in their careers, but rather felt the need to study such criminal behaviours as it would help in reducing the time to catch psychopathic criminals, who kill solely for the purpose of pleasure and therefore normal investigation methods fail to catch and identify them as the perpetrators. You cannot catch them solely through their MO unless you understand their mind and psychological behaviour which is different from a normal human being.

The series is set in the time frame of the year 2000-2004 specifically which the viewers need to keep in mind as they watch the show, since psychopathic criminals was not a normal deal back then and science was still evolving. The leads are also learning through the process of profiling and updating their knowledge by interviewing such criminals. One thing needs to be noted is that, there wasn't much development of such educational field of criminal psychology back then and therefore it had to be studied by our lead actors by themselves rather than learning it in a college or something. You should therefore enjoy the process of them getting better at their job each day and with each case, where they also learn to embrace their own hearts within such evil environment where the criminals do not repent or feel remorse over their killings and if had chance would still murder more people.

Also, there is a misunderstanding through the summary that the series only involves a single case i.e. of 'Red Cap' however this series includes more number of cases specially involving different serial killers.

I hope people enjoy this show as I did as an avid learner of criminal psychology.
Thank you!!