Not long after I fell asleep, the doorbell rang.
"Dingling, is anyone home?"
A strange man's voice sounded outside the door.
"Who is it, coming so early in the morning to disturb people's dreams?"
Shirakawa Yuki walked out in her pajamas with sleepy eyes.
"Well……"
Takagi Sheba outside the door looked at the white-haired dumpling in front of him with an embarrassed look on his face.
"I'm so sorry, madam, I am Takagi Wataru, the head of the third department of the Criminal Investigation Section 1 of the Metropolitan Police Department's Criminal Investigation Department. I am here to ask you about some information."
The last time Shirakawa Yuki went to the Metropolitan Police Department, Takagi happened to be on duty, so he never saw her.
"Ah, it's Officer Takagi. What happened? I'm Haruna Hoshino. I'm quite familiar with you, Officer Megure. Maybe I can help."
Shirakawa Yuki suddenly realized, no wonder it looked familiar just now, it turned out to be Takagi.
Takagi also looked at Shirogane with surprise, "Hey, it turns out you are the high school detective Hoshino Haruna that Officer Megure mentioned."
Takagi had heard of her and heard that her reasoning ability was as good as Kudo Shinichi's. He didn't expect to meet her today.
"Wait while I go change clothes, and we'll talk slowly."
After saying that, Shirakawa Yuki went back and changed into a silver-white windbreaker and followed Takagi Wataru into the car.
Staying at home is boring anyway, so I happened to go out to solve a case to relax, and by the way, I also had a good impression inside the Metropolitan Police Department.
"It's like this, Miss Hoshino. Recently, there was a serial murder case here in Yoneka Town. The murderer specifically targeted little girls and his methods were extremely cruel. So I wanted to ask if anyone in the area has seen any strange people."
After hearing this, Shirakawa Yuki frowned. This is a pervert. He can even attack a little girl.
"Is there any connection between these little girls?" Shirakawa Yuki asked.
Takagi Wataru replied: "We have investigated the victim's school, friends, and places he has visited recently, and we have not found any connections."
Shirakawa Yuki frowned, now she was in trouble.
"The killers are predators."
Seeing that Takagi Wataru wanted to ask, Shirakawa Yuki explained.
"Predators immediately start attacking when they come into contact with their victims. Such serial killers often have very strong antisocial personalities, are extremely aggressive, and often commit crimes unplanned."
"Go on and tell me, where are the places where these cases were committed?"
It's still a bit difficult to find the murderer now, so Shirakawa Yuki is ready to listen to clues first.
Takagi Wataru took out the police manual and said: "The first case occurred in Mihua Park. The deceased, Yayoi Takeda, was 7 years old. The time of death was between 8 and 10 in the morning three days ago."
"The second case occurred in an alley near the Rice Flower Shrine. The deceased, Mizujun Nainai, was 7 years old. The time of death was between 14:00 and 16:00 two days ago."
"The third case occurred near Mihua University. The deceased Yuuki Terai, 7 years old, died between 20:00 and 22:00 two nights ago."
After Takagi Wataru finished talking about these three cases, he looked at Shirakawa Yuki.
At this time, Shirakawa Yuki was taking out the electronic map of Tokyo that Dr. Agasin helped to invent some time ago, and what was drawn there.
"Ms. Hoshino?" Seeing Shirakawa Yuki's lack of reaction, Takagi Wataru couldn't help but shout.
"Wait for me, I'll find it soon."
At this time, Shirakawa Yuki was seriously looking for the possible residence of the murderer.
After a while, Shirakawa Yuki took a long breath, "Finally found it."
He handed the map to Takagi Wataru, pointed to the finally calculated location and said to him: "Now you can send people here to arrest people."
Takagi was confused. What happened? How could he arrest someone just by telling him the basic information about the case?
"Ms. Hoshino, are you sure the prisoner can be found here?"
"Oh, trust me, it's true."
Shirakawa Yuki said with a smile, looking confident.
"But Section 3 doesn't have enough manpower. Because of the Shinkansen bombing, Officer Megure went there with his brothers."
Takagi Wataru was a little helpless. He and Officer Sato were the only ones left at the police station today. Although the area calculated by Hoshino Haruna was already very small, a lot of people were still needed to go there.
"Then let's find the police officers from Section 2. They have nothing to do anyway. Kaitou Kidd didn't show up, so they have nothing to do all day long."
Shirakawa Yuki looked indifferent.
Takagi Wataru looked helpless. Although this was the truth, was it really okay to say it like this?
Takagi Wataru called Officer Megure for instructions. This was not something he, the inspection chief, could decide.
Officer Memu became serious after hearing this. After all, serial murders are very serious, and no one can guarantee whether the murderer will do it again.
After confirming with Shirakawa Yuki that it was not a joke, he also hurriedly spoke to Nakamori Ginzo from the Search Section 2.
Officer Zhongmori also took it seriously and quickly called the police officers from Section 2 to rush to the designated location.
Officer Megure on the other side also hurried over. The Shinkansen was almost over, so he had to rush over to see what was going on here.
"Sister Hoshino, are you sure the murderer is here?"
Officer Megure was still a little uneasy. After all, if he made a mistake, he would be embarrassed and thrown into the second class.
I couldn't believe it when I heard that Shirakawa Yuki didn't even go to the scene to see it. She just listened to Takagi talking about the case and took out a map to draw it.
"Of course, Officer Megure, I have seen the crime location of this case. The locations are not very scattered. It is obvious that they belong to 'field-type' criminals."
Seeing that all the police officers on the side looked half-informed, Shirakawa Yuki continued to explain.
"Carrying out serial criminal acts within a certain geographical range, centered on the criminal's own "psychological support point."
The "psychological support point" of such criminals is often their residence, workplace or public places they frequent. Territorial serial killers are relatively common, and Jack the Ripper is one of them.
Such criminals usually form a vacant area between their "psychological support point" and the crime area. This area is called a 'buffer zone', and the murderer often thinks that it is difficult to be caught in this way.
Therefore, I found the general range of his residence by analyzing the area where the crime was committed. But this is not accurate enough. "
Having said this, Shirakawa Yuki paused and attracted the attention of the police officers.
"Then what, sister Hoshino?" Although Officer Megure didn't understand, he felt inexplicably powerful.
“Next I used the Manhattan meter.”
Officer Megure was confused again, "Manhattan Metrology? What is that?"
"The Manhattan metrology is a mathematical model that can accurately calculate the residence of serial murder criminals.
Substitute the X-axis and Y-axis coordinates of the location of the crime scene into the formula to calculate the criminal's crime pattern and further infer the probability of the location of the criminal's residence.
The area connected by the highest probability points is the place with the highest probability of where the serial murderer lives. "
Speaking of this, Shirakawa Yuki finally explained how he found this place.
"So combining the results calculated by the two methods, the only location we finally got was here."
After hearing this, Officer Megure probably understood what Shirakawa Yuki had done.
