So who was the killer?

I really would recommend you to watch it again, but if you really want to know now...










Yes, Do-joon really did kill her (by accident... combined with stupidity/drunkenness). It was even shown, remember? ;) - even though it was told from the junk man's point of view, we can assume that he at least was honest about THAT detail of his story (which then resulted in Mother killing him).

The police thought that JP was the killer because they found the blood of Ah-jung on his shirt or somewhere (can't remember where exactly), so that was a much bigger evidence for them than Do-joons golf ball. JP explained that the blood came from Ah-jung's nosebleed when she got sexually excited... but they just didn't believe that. Poor Bastard!

What a great film! I just finished watching it and can't even begin to explain how deeply moved I was (and still am!) by this fantastic piece of cinema! Although the first hour I wasn't quite sure what I was watching and couldn't really put my finger on it (although I'm familiar with Bong's previous movies), the more captivated I was with the second half and thus with the whole movie.

With this, Bong has now finally replaced Park Chan-wook as my favourite korean/asian filmmaker. What an artist, really!

The girl was probably on her way to sleep with the merchant (remember that he had been having sex with her before, since he was in her cell phone collection), but before she got to it, she snapped while Do-joon was following her and hitting on her, calling Do-joon a retard. We know how Do-joon reacts when he gets called a retard, and in combination with being hung-over, he threw the rock back at her, accidently killing her in the process. The merchants story has merit if we consider what he brought up. He told the mother about the "retard" remark that got Do-joon off, but he also recalled Do-joon meditating, as the former poster explained. Now, that would be impossible for the merchant to know, if he didn't know Do-joon, which he obviously didn't.

Remember when Jin-tae (who apparently had been studying about crime scenes) described that the murderers probable cause for putting the victim on the roof, was so the everyone could see? Now, almost at the end of the movie, Do-joon, who unconsciously recalled the event, by describing what he probably would have done, by putting her up on the roof for everyone in town to see, if he was unable to call for help, which essentially what really happened. All the dots connect here.

AS for the JP kid, we know from the movie that the victim started bleeding from the nose when she had sexual thoughts (by the flashback from the photo developing service and JP's reason why he had her blood on his shirt).

So in a nutshell, yes, Do-joon killed the girl (unintentionally), and realising the truth, the mother got rid of the Merchant as he was heading for the phone to call the police.

[deleted]