Conan Mobile Toilet Murder Drowning Incident

In the "Detective Conan" series, the truth behind the mobile toilet murder drowning incident is that the murderer used a simple device to create the illusion of 'drowning on dry land,' causing the physical education teacher to drown in the mobile toilet through physical means.

Background and Key Figures

The incident began when the毛利 (Mouri) group changed their itinerary to an indoor bowling alley due to rain, during which Shiranami and Kyogoku Makoto had a conflict. The victim, Tanba Seiyasu, was a physical education teacher who had been drinking and sobering up in the car before the incident. The accompanying middle school teachers, Monai Michiko and Masaki Namio, had originally planned to play bowling with him, but he did not arrive on time due to his drunkenness.

Core Conflict and Initial Investigation

The police discovered Kyogoku Makoto's fist imprint on the victim's abdomen, and his conflict with Shiranami made him the primary suspect. However, Shiranami pointed out that if Kyogoku Makoto wanted to kill someone, he could do so directly with his fists, without resorting to drowning. Subsequently, the police found two burn marks on the victim's shoulder, suspected to be caused by a stun gun. Monai Michiko and Masaki Namio were listed as suspects because they possessed stun gun tools and had conflicts with the victim. However, both were with the group searching for Tanba at the time of the incident, lacking the opportunity to commit the crime, and the case reached an impasse.

Key Clues and Revelation of the Murder Method

After returning to the scene, Conan discovered the following clues:

• Stratum subsidence and ground inclination: The ground near the toilet was severely inclined due to stratum subsidence, and there were water stains in the corner, indicating that water might have gathered from high to low areas.
• Vent tape marks: The vent above the toilet was taped, suggesting that the murderer had injected liquid into the interior through this opening.
• Aluminum cans and kerosene: There were four aluminum cans with burn marks in the trash can. Combined with the smell of kerosene at the scene, it could be inferred that the murderer used aluminum cans and kerosene to make a simple device.

Murder Method: The murderer modified the aluminum cans into containers, filled them with kerosene, and lit them. Using the air pressure generated by the combustion, water was forced into the mobile toilet through the vent. Due to the inclined ground, the water quickly accumulated to the height of the victim's head. Additionally, the narrow space of the toilet prevented the victim from escaping in time, ultimately leading to death by suffocation and drowning. The residue from the kerosene combustion and the burn marks on the aluminum cans became key evidence, while the tape marks on the vent proved that the murderer had attempted to control the direction of the water flow.

Conclusion

This case created the illusion of 'drowning on dry land' through physical means. The murderer utilized environmental flaws and a simple device to commit the crime, which was ultimately uncovered by Conan through detailed reasoning.