Hello i wonder if you can reccomend me dramas or movies where korean investigators, normal people, prosecutors or whoever are searching for murder,(i want that feel of keep guesing who did it not to knwo who is killer from episode 1), with all suspense and stuff need something to keep me hooked,  ty in advance for any help. :) 

Ahhh here we go...Here is a decent list ;) I LOVE these sorts of dramas. I've suggested a few with the crime / investigation genre. There is bound to be some sort of murder or major event in all of them at some point.

  • Bad Guys -  A mad cop puts together a team of criminals to fight other criminals with the promise of reducing their jail sentence. Includes as a psychopath, gang leader, assassin etc. 
  • Duel - Ok...So you may think you know the master mind behind all the events in this drama, but you will be very VERY wrong. This is action filled and is extremely suspenseful. If you're a fan of the crime / suspense genre, I wouldn't skip this drama at all. + this is by far my all time favourite drama.
  • Criminal Minds - Need I say more :o 
  • Hello Monster - Ahhh….I had so much trouble with trying to guess this drama at times. It is an extremely good watch imo. there aren't as many action scenes, but it does well in the crime / investigation department. + The actors are all amazing.
  • Remember War of the Sun - You can sort of figure out who the bad guys are, but there are plenty of twists and turns. Be warned, it is a tear jerker. The main lead becomes a lawyer to seek revenge and free his father from prison.
  • Silenced - This is both a disturbing and sad story, as it is based off a true story. It is suspenseful and I guess you would call it more of an investigation & Tragedy story. It is only a movie though.
  • You're All Surrounded - A decent watch, could've been better in the plot. but I say it would suite what you are looking for. 

ty alot for your recommendations <3 

  • Memories of Murder 
  • Veteran
  • Memoirs of a Murderer 
  • Forgotten 
  • Our Town 
  • Soul
  • Gap Dong 
  • Black 
  • Hidden Identity 
  • Falsify
  • Who Are You 
  • Blind
  • Phantom 
  • Defendant 
  • Master's Sun 
  • Confession of Murder 
  • Suspicious Partner 
  • Terius Behind Me 
  • God's Quiz
  • Item
  • While You Were Sleeping 
  • Vampire Prosecutor 
  • Cheo Yong

I 2nd @echelonvipJJ86 recommendation of - Signal -
It is absolutely amazing. The best crime drama I have ever seen in any korean drama. Definitely give it a try.
Another very nice one is Children of Nobody. That just finished airing a few weeks ago. Its well done too.

memories of murder - i bet you could never guess the murderer !

stranger

children of nobody