Three people who are troublemakers are found dead. After the police found 30 million yen in Yasuho Shida's apartment, Conan suspects that they are the culprit of the robbery three days ago.
Murder
Location:Park
Victim:Takeshi Mitsumoto
Age:35 years old
Time:7:00 pm
Cause of death:Blunt-force trauma
Suspects:Yorimitsu Hosaka
Murder
Location:Apartment
Victim:Yorimitsu Hosaka
Age:35 years old
Cause of death:Stab wound in the chest
Suspects:Yasuho Shida
Murder
Location:Apartament
Victim:Yasuho Shida
Age:35 years old
Cause of death:Poison inside a bottle
Suspects:Takeshi Mitsumoto
Robbery (Past)
Location:Haido City
Time:3 days ago
Suspects:Takeshi Mitsumoto, Yorimitsu Hosaka, and Yasuho Shida
Three days ago, 30 million yen in cash was stolen from a financier in Haido City. He was robbed by three masked men.
Conan deduces that they become greedy and decide to kill each other.
Later, Chiba meet a child named Mamoru Nishikawa, who saw a suspicious man trying to enter Shida's apartment. Chiba later suspects the victim's middle school teacher, Kokichi Minamide. Chiba discovers that Minamide had tried to reform those three victim's behavior during middle school, but his efforts never paid off. Chiba deduced that Minamide decide to kill them after he heard that they stole 30 million yen.
In the end, Minamide is confirmed to have an alibi. They continue to search the suspicious man. Meanwhile, Conan ask Mamoru more about the suspicious man. He later found the suspicious man in another apartment building.
It turns out that the suspicious man, Kensaku Kitahara, came to visit his newly wedded daughter's household. He meant to visit room 402 in building K, but mistakenly tried to get into room 402 in building A, which is Shida's. He only realized his mistake after he saw the door plate, but Mamoru saw him. He threathened Mamoru because he afraid Mamoru will tell his daughter and her husband about his mistake. He wore a mask because he had a bit of a cold, and used sunglasses to hide his eyebrow that was accidentally shaved off when he went to get a haircut.
Megure later received a phone call. The forensics found the pipe with Mistumoto's blood and hair with Hosaka's fingerprint on it. They also found the knife with Hosaka's blood with Shida's fingerprint on it. Conan, through Kogoro, is sure that they will also found the bag of poison used to murder Shida with Mitsumoto's fingerprint on it. Which means, Takeshi Mistumoto was killed by Yorimitsu Hosaka, Yorimitsu Hosaka was killed by Yasuho Shida, and Yasuho Shida was killed by Takeshi Mitsumoto.
Conan advises the police and detectives that they should not read too deeply into situations and head in the wrong direction, and they also should not assume people unrelated to a case as suspects.
A rather unpopular type of detective/mystery school.
Simply about the detective who attempted to use his deductions to reach the truth, but came to the false conclusion.
Which the truth is often coincidence, accident and so on, the case did not exist at first.
These type of works satirizes the statement that "The only absolute truth of the case" and "A genius detective who can always solve a case" from classic mystery works.