Crime / Mystery

Who Are You? - Police officer comes out of a six year coma able to see ghosts. She works in the Lost and Found solving cold cases and trying to figure out what happened six years ago. - u/arahzel

Gapdong - It's really really good. It's a murder mystery about how people in the present time are mysteriously being killed in the same way that a serial killer killed his victims 20 years ago.  - u/snsdfour3v3r

I remember reading dramabeans covering this as it aired, and quite frankly it was one of the first dramas/shows I payed attention to in terms of production quality. Just everything about the director of photography's choices about the way certain characters were framed in shots was astounding. Not only that, the three leads are just superb in their roles. Highly recommend this drama to anyone.  - u/toyaqueen

Bad Guys - It's more like a crime procedural with an underlining mystery that follows the main storyline.  Great acting and characters.  No romance if that's a concern.  Violent and gory at times.  Could definitely be triggery.  - u/shorty_cakes

I'll jump in and say one thing I like about Bad Guys is the irony of the title. None of the characters are all bad or all good. In fact, nearly all the characters do some endearingly good things, and nearly all the characters do some unbelievably bad things.  It has plenty of three word sentence, low voice machismo that one expects from an action genre, as well as tons over fun, over-the-top fight scenes with main characters in ridiculous odds. It's quite predictable, but fun to watch.  - unknown

Healer - This is a heartwarming drama about the mysterious past of three strangers and how it connects them.  It is a wonderful combination of mystery, romance, comedy, crime, detective, and a little bit of action.  The pacing is tremendous, switching between all of these genres seamlessly while keeping you hooked to the story.  The characters themselves are fantastically well written and acted.  You are never disappointed switching scenes because every single one of the characters is interesting.  It is my favorite show of all time and I think it is worth a shot if you are the least bit interested in a heartwarming mystery.  - u/kdramaaccount

Healer - A mix of romance, drama and thriller aspects.  Great chemistry between the leads and relatively solid storyline.  Fantastic cast.  - u/shorty_cakes

I Remember You / Hello Monster is a good psycho-thriller kdrama. Well its not really as action packed as the American hit tv show Criminal Minds, but it is still successful in giving you a look into the mind of psychopaths and serial killers. It also gives you an idea of what triggers them to do a slew of killings and at the same time it manages to show their humanity even if they are practically devoid of emotion and compassion. Haha. The actors are really good too. Seo In Guk and Jang Na Ra's Chemistry is on point :) it also stars the cutie Park Bogum - unknown

Signal - A team is formed to solve cold cases. An officer can communicate with another officer from the past using an old police radio. - u/vcconut

Signal embedded itself in my heart. I loved the noble, courageous police officer from the past. The suspense totally got to me. The combination of evil serial killer and toxic political corruption was compelling. And I thought the use of the old police radio was just right -- eery but fitting, and an aid, rather than a solution, to the police officers' struggles in both past and present.  - unknown

"Look Out"/"Guardians" - Story about a group of people who get together to overcome their pain of having lost their loved ones to crime by fight justice for themselves and other people, after experiencing the harsh corruption of the legal system.

Why you should watch: This drama features characters who are all 3D and is packed full of character development, heart-wrenching moments, badass characters, and incredible twists. - u/JadeOlivia

Tunnel - A cop from the 80’s pursuing a serial killer is suddenly transported to the future/present day Seoul through a tunnel to the present day where he meets and helps his daughter find a serial killer.

Why you should watch: Another great OCN drama featuring time travel, mystery and criminal elements. A story that will hook you and an excellent cast to pull it off well. Great bromance and rivalry, you will laugh and cry.  - u/sianiam

I Miss You - Such a great drama. A boy and girl meet when they're young and really like each other. The girl gets kidnapped and disappears. The boy grows up into a detective that's still searching for her all those years later when a new couple with "apparent" connections to the kidnapping come back into town. Give it a few episodes, this is a really good drama. Tied for my favorite. - u/lucidzero

Defendant - A thriller about an amnesiac (done well!) prosecutor who's put on death row, having to find out why he's there in the first place and how to clear his name, with some amazing acting by Ji Sung and Um Ki Joon. - u/migster99

Queen of Mystery Spunky housewife plays detective with the flair of Sherlock Holmes, and forms a funny, competitive, argumentative friendship with an actual detective who's exiled himself from his wealthy family because of his tragic past. This series actually felt like a weekly mystery show, with the pair solving several different crimes. I never got tired of the running joke about how horrible her cooking is.  - unknown

Secret Forest(Stranger)- A emotionless prosecutor works with a warmhearted cop to solve a case.  - u/goldenbeee

Secret Forest/Stranger - the best cinematography, cast, and storytelling I've ever seen in a kdrama. Every second is tightly edited so that each shot is important, and features a lot of subtlety and reading between the lines. Focuses only on one case so it might seem slow for the first four episodes but is extremely compelling. Great to watch for character development, stellar acting, and the one-of-a-kind relationship the main leads have.  - u/eggmelon

Missing 9 - The first episodes are reminiscent of LOST, except there is a killer among them.  And the mystery is of course finding out who did it, once the survivors start returning to Korea.  Has a lot of comedy and a lot of beige clothes.  Warning though, some don't like the surreal ending.

Why to watch:  It's quite funny.  Good ensemble cast including a couple of Idols, Jung Kyung Ho with orange hair and the ever humourous Oh Jung Se. - u/LcLou02

Life on Mars - A by-the-rules, modern police detective finds himself in 1988 and finds links there to the serial killer he was chasing in the present day. He has to learn how to work without any of the modern conveniences. Fun to see him adapting to the old fashioned way of crime solving. The whole time he is trying to figure out how to get back to the future. Why you should watch: Jung Kyung Ho does a terrific job in this role! Great bromance develops with Park Sung Woong. Good pacing and interesting plot.  - u/LcLou02

When the Camellia Blooms - serial killer meets romantic comedy. A young single mother moves into a close-knit community to open up a bar. She is initially shunned by the locals, but then she meets and falls in love with the local golden boy, an earnest and warm hearted policeman. Unfortunately, a serial killer on the loose intends to put an end to this budding bliss.  - u/FoucaultsFarts  

When the Camellia Blooms - Opens immediately with the mystery of the identity of the young woman who recently died in the local lake. The story line of the serial murderer who mysteriously stopped 5 years ago weaves through this Melo-Rom-Com-Crime Drama.  It's got it all, in perfect balance.

Why to watch:  You will love the characters, especially the enthusiastic young police officer who has returned to his small home town who sweeps us along as he gathers clues and wins the heart of single mom, Dong Baek (Camellia).  Great neighbourhood ensemble cast. - u/LcLou02

When the Camellia Blooms  - Is the killer actually someone we know? Can you be objective about people you knew since childhood? What kind of neighbours are worst? What happened to the cats? Although mostly about the love story, the crime is well woven into the drama and an important part of the story. - u/the-other-otter

Time Between Dog and Wolf: A serious and dedicated NIS Agent gets killed in an accident leaving his adoptive parents, brother and childhood sweetheart distraught. But five years later, a badass gangster with the same face enters their life with motives of his own.

Why to watch: To revel in good old revenge kdramas which seem to have gone with the wind in the present Kdramaland of rom-coms and bromance between Lee Joon Gi and Jung Kyung Ho is a bonus :) - u/ dreamerimagine1

I can hear your voice - Slightly supernatural noona romance with six years difference between the lead characters. Who becomes a killer, and why? Comedy and suspense and personal development. - u/the-other-otter

He's a Psychometric - On friendship, creating new families, forgiveness, being blamed by the public. - u/the-other-otter

He is Psychometric: A crime thriller with minimal romance. It also has a bit of fantasy. The ML, FL and SML are connected with a murder case that took place and which turned into a cold case due to corruption. The ML gains abilities through this accident and after many years the ML, FL and SML end up solving the cold case again. This drama has one of the best plot twists and it keeps you on the edge of your seat for the most part. It starts off slow but it picks up pace after the 3rd or 4th episode. I loved the bond between the ML and SML, the chemistry between the ML and FL was really nice too. It's an enjoyable drama. - u/Fatooz

Pride and Prejudice: A drama about internal strife within the prosecutors' office between prosecutors who seek justice and prosecutors who seek power. The crimes portrayed contain the usual crime drama regulars, such as murder, drugs, bribery, etc. While none of the cases are particularly memorable, the drama is a good showcase of solid to excellent acting from its entire cast. Worth watching if you like any of the actors and want to watch more of their works.  - u/myweithisway

The Girl Who Sees Scents - This is another fantasy romance crime thriller. The FL witnesses a murder and the serial killer leaves a barcode number on the body he kills. The FL while running away meets with an accident which leads to her developing the ability to see scents. The ML looses his ability to feel touch due to the same accident. The ML and FL end up meeting after many years and end up solving the murder case. I loved Namgoong Min's acting in this drama and he does full justice to his role. I also really liked the FL's character. Although the romance isn't that great the plot is pretty interesting and the concept of how the FL can 'see' the scents was pretty unique. - u/Fatooz

While You Were Sleeping - A fantasy crime thriller romance drama. The FL can see the future of people in her dreams and tries to save them. The ML can see the future of the FL in his dreams and this leads to him saving her.  Another unique concept. I liked the bonding between the three main leads, especially the SML's character and acting outshone everyone else. The friendships were the best part about this drama. - u/Fatooz

Vincenzo - A crime thriller with minimal romance. A mafia consigliere returns to South Korea after many years to get his retirement fund but ends up getting involved in a corrupt case. He joins hands with the FL to bring down the baddies.  Loved the acting, plot, chemistry, cinematography, soundtrack and direction so much! It starts off slow and I got into it only after the 4th episode but after that it was an awesome drama. It was entertaining throughout. The over-the-top comedy was not my thing but it was still well done in almost every aspect. - u/Fatooz

The Uncanny Counter - A fantasy crime thriller. Four random people get selected as 'counters' who have to catch evil spirits wandering in the living realm and send them to hell. A series of events leads them to solving a murder case through which the ML and SML are connected. This drama surprisingly is super wholesome and the team work is the best part about this drama. The first half was solid and keeps you on the edge of your seat throughout. The action was also top notch. - u/Fatooz

The Smile Has Left Your Eyes - This drama is a mix of all genres honestly. It has crime, thriller, romance, drama, etc. The drama is about two star crossed lovers, a chance encounter ends up bringing them closer to each other but as they get close more and more misfortunes keep happening. This counts as a crime thriller because the ML is a suspect in a murder that takes place and this leads to all the misfortunes between the ML, FL and SML. The first half is a bit stagnant but I loved how the ML is an anti-hero and the acting was on point. The chemistry between the main leads was outstanding and the drama will have you in tears, especially the second half. - u/Fatooz

The King: Eternal Monarch - This is a sci-fi mystery romance drama. This drama feels different in every episode. Some episodes give epic vibes, some give ethereal romance vibes, some give pure mystery thriller vibes. It's different from your usual KDramas and gives more of a Western feel. This drama is about the ML who is the King of a parallel world - The Kingdom of Corea, he ends up travelling to Republic of Korea and a series of events start happening. It's about how he along with the FL save the two worlds from misfortunes. I loved the romance in this drama because it was so trope free. Surely, the PPL was a bit annoying and in the face. The drama is also far from perfect but it was unlike any other dramas by Kim Eun-Sook. I loved the World building. The bromance was an add on. It has beautiful cinematography and soundtrack as well. - u/Fatooz

Come and Hug Me - This is a crime romance drama. The ML's father is a serial killer who kills the FL's family and after many years the main leads meet again when the ML has become a detective and the FL is an actress. I loved the chemistry between the main leads and the romance was really nice. The crime part was a bit cliché but overall it was an enjoyable drama. - u/Fatooz

Beyond Evil - This is a psychological crime thriller. A young detective gets transferred to a small district and he is partnered with the officer who was a suspect to a murder 20 years ago. As soon as the young detective gets transferred the serial killings start again leading to the two main leads uncovering the truth about what happened 20 years ago. The tension between the two leads was amazing and the drama keeps you on the edge of your seat throughout. You can't afford to miss out even one scene because every scene was important. It has also won 3 Baeksang awards and is highly acclaimed. - u/Fatooz

Beyond Evil is worth watching because of its stellar acting performances throughout the drama about finding the true murderer. It will keep viewers hooked until the end with several twists and emotional expressions. The OST is great and matches the mood of the drama. Beyond Evil deserves the awards it has received. - u/dramafan1

Flower of Evil - This is a romantic crime thriller. The ML is hiding his identity and living with his family after lying to them for the past 14 years. A series of events lead to the FL who is also his wife uncovering a truth that was never supposed to come out. This drama definitely keeps you hooked and promises top acting by all actors. It has a strong plot and it never fails to deliver. I especially loved the chemistry between the main leads and the relationship between the ML and his daughter was the highlight of the drama. - u/Fatooz

365: Repeat the Year - This is a sci-fi crime thriller. A group of people get a chance to "reset" their lives by going back a year and changing events that would save their lives. However as soon as the "reset" takes place these people automatically become part of a death game where one by one members keep dying. The ML and FL join hands to save their lives but also uncover the truth behind these serial killings. It's a drama that will keep you on the edge of your seat and it's also short. - u/Fatooz

Confession - A man who believes his father was framed for murder becomes a defense lawyer who re-investigates his father's case on the side, trying to uncover the truth behind a tangled web of corruption and secrets. There were multiple plot arcs that all weaved together seamlessly and moved at a brisk, steady pace, and the protagonists had excellent relationships and communication with each other. Overall this was one of the most riveting and high-quality dramas I've ever seen! - u/craftsycandymonster

Memorist - Dong Baek is a famous superpowered detective with the ability to read people's memories and feel their emotions. When a high profile murder case comes up, he has to team up with genius profiler Sun Mi to solve the case. Memorist is, honestly, one of the most insane dramas I've seen. The show sets up an incredibly dark and tense atmosphere that doesn't help but feel insanely thrilling and manages to keep you engaged throughout. The plot twists and turns like crazy and just when you think you're onto something, you realize that you've been played. Excellent, gripping and one of the best thrillers I've seen. - u/TotoroTheGreat

Train - After a series of bodies are found at an abandoned train station, Seo Do Won and the police start investigating it, assuming it is the work of a serial killer. But, after Han Seo Kyung, a woman from whom he hides a deep secret and who he wants to protect, gets entangled in the case and killed, Do Won accidentally ends up on a ghost train that takes him to a parallel world where Seo Kyung is still alive, but so is the serial killer who did all the murders and dumped the bodies in his world. A very interesting take on the parallel worlds concept, Train is quite a gripping story. - u/TotoroTheGreat

The Good Detective - a well done classic murder mystery. An experienced detective and his young partner stumble into a series of clues that hint at a cover-up and wrongful murder conviction. They unravel the clues and discover corruption in high places, where money and influence lead some men to believe that they are above the law or the morals that bind lesser folks.  - u/FoucaultsFarts  

My Name - After her father's death, a revenge driven school girl puts her trust and belief into one of the most powerful crime bosses and enters the police force under his orders with his help to find who murdered her father.  - u/micuiyi