Something which hopefully feels like The Bad Kids/ Snail Falls in Love/Love me if You Dare/Medical Examiner Dr Qin... romance is welcome but not needed xD.  Just recommend anything good in this genre haha. Must be Cdrama please :))

Would A Murderous Affair in Horizon Tower and The Long Night be of interest to you? Their vibe seems to be similar to The Bad Kids. 

The absolute best crime cdrama is Burning Ice . It is so mindblwoingly good, and so absolutely well done from a psychological aspect. It also is the previous work that the Light on Series is inspired on. Highly recommend it.(It also has a romance story)

Then for other recommendations I would 2nd The Long Night, which follows the same main  character from Burning Ice, however this one is completely different. (no romance)
And also A Murderous Affair in Horizon Tower This one is quite complex and has many many layers. Its well done (some degree romance too)


Additionally I recommend you The Kidnapping Game. It is also part of the Light on Series, but also has a absolute awesome romance story. Very well portrayed.

Burning River is also another awesome crime-drama that just recently finally got subbed. Its very gripping and amazingly done. (no romance)