After investigating the three suspects, Conan tranquilizes Kogoro and with his voice changing bow-tie, reveals that the murder was an accident. Conan reveals that the eldest son Rokuro Yaguchi witnessed his father's death through the webcam. The video shows that Hisaemon had a myocardial infarction and accidentally shot himself. Conan also reveals that after his son tried to rob his safe, he cried in sorrow as evidenced by the salt on Hisaemon. Once the police were able to open Hisaemon's safe, they find a loan contract to which the money went to his sons.