Board Thread:Fun and Games/@comment-29585050-20161122101745/@comment-29711200-20161123085413

oh waaaaait. i think i got it.

you went into the store room. the murderer takes the padlock off the door and replaces it with his own. he leaves. you come out and shut the door, and it locks itself. the murderer kills his victim and opens the store room with his own key, since he replaced it while you were in the store room. he then closed it up again and replaced it with your own padlock.