Doubt

Both are Crime Drama Thrillers with the Main Lead working in/ for police department (criminal profiler or a forensic expert), now living with a teenage daughter, who is forced to live with him after her parents' divorce n after her mom's death.

Father have strained relationship with daughter for abandoning her n her mom in her childhood

Daughter leaving her traces in the crime scenes of multiple murders.

Father suspects her to be a murderer and goes to every extreme to prove her innocence, ahead of the detectives investigating the cases, by conducting secret investigations on his own.

Thriller, Mystery, Crime, Drama

Both have dark stories, investigations based on psychoanalysis. As for me, the characters are very similar in type! A very similar picture and color palette!

Thriller, Mystery, Psychological, Drama

Both have dark stories, investigations based on psychoanalysis. It's a very complicated story! A very similar picture and color palette!

A public official's child/children got involved in a crime and they did everything to hide the truth.

A public official, a Judge in this case, discovered his son committed a crime and hid it while believing it was only a mistake. When the truth of the matter is, his son did plan the crime and led his father to believe otherwise.

In both dramas Han Seok Kyu plays a leading police officer that is known for solving cases. In both dramas he is confronted with colleagues/family members that may be involved in a murder case and be the culprit of it.

Both have the same vibe. Both stories are Dark and centred around a murder mystery. In Doubt, the father, who is a profiler, suspects his daughter of murder, and in Nine Puzzles, the Detective in charge suspects the niece of the murder of her uncle, but the niece later becomes a profiler.

Both dramas are crime thrillers with a police detective/ profiler as a main lead

Both deal serial murders from the past n present / connected crimes.

Even the main lead is suspected of being a murderer (awaken) or a parent to the suspected murderer (Doubt),

Both have a Revenge Seeking main lead (awaken) , trying to prove his innocence by catching the true culprit and the same goes for the main lead in Doubt for his daughter.

Both deal with the unsuspecting killer...the person who inserts themself into an investigation, the person that people look past as the killer, the person that someone knows is the killer but is halfway protecting them or turning a blind-eye. They are the same because both the main leads that are the likely killers are mentally ill, except one is aware of why they are doing what they are doing, and the other has no memory (if my memory serves me correctly) that they are even killing people.

Both have that slow pacing that you love to hate when it comes to suspenisful , mysterious, who did it dramas. That said, you are going to like this drama.

Both stories are whodunnits involving family members of police officers and the police. Both are tension filled thriller mysteries.

Both of these series have very complex and intelligent writing in terms of framing suspicion. They'll have the viewer convinced of who the killer is based on what they've plainly laid out for us, only to then shock us and turn us on a new path towards someone else- again and again.

If you are looking for the same kind of recommendation, you should definitely watch it. Also, Kim Nam Gil is the main actor in kmovie

Similar "dark vibes" with unhinged characters. A drama that delves into dark psychology. FL leads have a bit of a similar vibe where both give off this look as if you're staring into the pits of darkness and they know your deeest secrets. Hyper Knife's FL is more unhinged though, whereas Doubt's is more meticulous and not as outwardly unhinged (though both show their rebelious sides and are arrogant in the way they do things their own way).

Jang Tae Su is a legendary criminal profiler in Korea. He was one of the first in his field and paved the way for criminal behavior analysts in the country. He has gained absolute respect and trust within the police organization. At home, he is a single parent and raises his daughter by himself. Jang Tae Su works on a murder case and realizes that his daughter is involved in the case. The discovery shakes everything in his professional beliefs and his relationship with his daughter. To protect his daughter, Jang Tae Su struggles to reveal the truth.

(reccing this as of episode 2 of Doubt airing)
Both feature an arc regarding a child killing a child now grown up, and the mystery of if they are capable of doing so again in adulthood. There is the push and pull of the perpetrator's family wanting to trust believe and understand them, but ultimately not being able to let go of that suspicion.
Both the killers have a stoic and unremorseful personality assisting in the struggle to accept them and their words.