A serial killer (Kwak Si-yang) is on the loose, driving a stolen car to a forest on the outskirts of Seoul with his latest victim tied up in the boot. Stopping for petrol, the murderer gives an attendant cash without saying a word, loud dance music playing on the radio. Putting in the fuel for him, the attendant starts to hear a dull thud from the back of the car, understanding dawns on his face, and in that moment he and the killer’s eyes meet. He has a choice: do something or don’t. He chooses the latter, to save himself, a decision which opens The Witness and foreshadows the story to come.

Returning home after a drunken night, Sang-hoon (Lee Sung-min) is one of three residents to be awake in the early hours of the morning when the ruthless man commits his latest kill. “Did you hear someone scream?” his fellow tenant asks him as they share the lift together, he didn’t, he tells her. It’s only after he steps inside his home, checks on his wife and daughter, and relaxes on the sofa that he does hear it: a woman desperately calling for help. Sang-hoon cowers at his window, watching as the murderer towers over the young woman, striking her with a hammer again and again until she lies in a pool of her own blood. To his dismay, Sang-hoon is caught looking at the scene, and while he decides not to admit to what he saw to protect his family, he soon discovers that he’s next on the killer’s to-do list.

In a time when humanity seems to be at one of its lowest points in decades, The Witness proves that it could get even worse with the way these characters react to a killing that is -quite literally- on their doorstep. They deliberately choose not to co-operate with the police, shame those who try to ‘bring down the reputation’ of the complex by asking questions, and the witnesses remain obstinately quiet until it’s too late. Things become so exasperating as the film progresses that, as an audience member, it felt like the only way to get Sang-hoon out of his state of indecision was to reach into the screen and shake him out of it. When he does -eventually- decide to do something about the killer it feels forced, as the film culminates in an intense clash between the pair in the rain and mud, which apparently requires divine intervention to resolve.

Kwak Si-yang, for his part, does as well as the script will allow him to in the role of serial killer Tae-ho. Given little-to-no dialogue and armed with a dead-eyed stare, he’s certainly a menacing presence in Sang-hoon’s life, but it also feels like the actor is wasted here. Sure, it’s not necessary for the audience to sympathise with a sadistic killer, far from it really. But, one can’t help but think that Tae-ho would have been more threatening had Kwak been given a chance to do something with the character other than disappear and reappear like the bogeyman. The ruthless killer is the least off-putting thing about the film, though, as it’s the inaction of the residents, and their deliberate obstinance in the face of murder that is truly frustrating.

The Witness benefits from being different to what might be expected of a film in the genre; this is not a case of a grisly detective going up against a heartless killer, chasing each other to the ends of the earth (though there is a police officer who fits the description here). The film has its moments, where the intensity of a scene or jump-scare works just right, even if they come straight out of a textbook serial killer film. The underlying irritation that the audience will feel regarding the characters, and their dodgy social and moral values, dampens the effect of these scenes, though. It leaves a bad taste in the mouth, but does beg the question: What would you do?

The Witness was screened as part of the London Korean Film Festival.