tr8intobusan

The way of filming in Black Out reminds me of Gap Dong.
Both series are about a series of murders of girls in a small town.
Both series have a detective who is hell-bent on finding out the truth of a case that happened nearly 20 years ago.
Both series have a lot of unexpected plot twists and at times twist things every two seconds.

The serial killers aren't similar, in fact Door Lock kind of has a lame ending, but 80% of the movie from the beginning is very interesting, both have a lot of suspence, feel threatening and both female leads end up killing the killer in the end.
In 'Door Lock' the serial killer is more gruesome.
In both the killer is obsessed with the female protagonist - but in 'Somebody' it's love, while in 'Door Lock' it's just another victim of stalking, obsession and not 'united by murder' at all.

Midnight is a movie about a serial killer who stalks a handicapped, yet very determined and clever girl. The serial killer, played by Wi Hajoon is very similar to Yuno in 'Somebody'.
Both have a plotline of a handicapped girl being tormented by serial killer - in 'Somebody' the girl is in a wheelchair, while in 'Midnight' she's deaf and has to get away from her assailant using wit.
Both serial killers are psychopathic and have a few endearing moments with the victims.
Both girl leads get revenge on the killer.
Both are suspenceful.