The next day, Kogoro reunites the four suspects to the scene and Conan tranquilizes him. The culprit made a trick to shot the gun automatically, by tying the weapon to a chair with strings, place it in line with a mirror made with aluminium foil from the house next door. The gunshot will react to the light reflected by the mirror and shot the victim. The culprit use this method because it is needes to create an alibi, so the culprit is the only one with an alibi, Naoya Akaike. The proof is that he pretended that the victim had a dentist appointment and also pretended to cancel it, because if he knew that Tawake will die, there was no point to make the appointment. The motive is that Tawake used all of his students as ghost-writers and Akaike wanted to free everyone from Tawake.