Why didn't they arrest the stranger? (spoilers)
There are lots of parts in the movie that are open to interpretation and may have various meanings but one scene just did not make sense to me at all.
When Jong-Goo, the other police officer and the deacon go up to the stranger's house after speaking to the witness who claims to have seen him eating an animal raw they start searching the place and find the secret rooms one with evidence of some kind of suspicious ritual and the other with loads of photos of dead people and personal items (including Jong-Goo's daughter's shoe) why on earth didn't they arrest the guy?
The dog attacks them and then the stranger appears and calls it off then walks into his house and they just kind of look at him in awe or maybe fear then the next scene they are in the police car and his mate is looking really sickened and produces the girl's shoe and mentions the photos but why they didn't arrest or question him at the house when he first turns up is very hard to understand.
Another smaller oddity I noticed is none of the police ever draw their guns despite being attacked by vicious dogs, zombies, people trying to bite them etc.