It is found in a room adjacent to the computer room. Although the room has two doors it can only be accessed through the last room. The player can then unlock the other door from the inside leading back into the ruined hallway. It cannot be obtained the first time visiting the station when rescuing Jin, only during the side quest "Matter of Justice", with the door to the room opens so the player can complete the quest. Note that the door only opens AFTER taking the quest item "Tim's Files" and the player must kill an Infected before getting it.