Tokyo Unnatural Forensics

Chapter 226, Good News Arrives from Kanagawa
On September 20, after a good night's rest, the Metropolitan Police Department officers headed to the Igarashi residence in Yokohama.

Upon arriving at the scene, Uesugi Muneyuki discovered that the Igarashi residence was a detached house that was not very large. Although it was a detached house, the living area was only about 100 square meters. There was a backyard at the back, and the front door had a heavy security door and an alarm system. There were no signs of breaking in.

"Excuse me!" The Metropolitan Police Department officers stepped into the house.

“Because Aiko Igarashi lived alone, she had basic safety awareness. Before the incident, she sought help from Executive Director Sato and the company, saying that she felt someone was following her. As a result, Mitsui Properties installed a security door and an alarm bell in her home.”

Uesugi Muneyuki said to Ikeda Erena and Ishihara Mikoto behind him, as well as Kosaka and Kashiwagi from the Metropolitan Police Department's First and Third Divisions, "This is why the Kanagawa Police Department believes it was an inside job, because it would be difficult for a stranger to knock on Igarashi Aiko's door after she had already been put on guard."

"I see." Both Erina Ikeda and Mikoto Ishihara looked a little awkward.

Last night, they were all scolded badly by Miss Minami. Among them, Rena Ikeda was warned by Miss Minami that if she cheated again, she would be sent on a business trip to Hokkaido for a month.

Mikoto Ishihara's unease was different. Miss Minami hadn't expected to encounter her in Muneyuki Uesugi's room, which led her to suspect the relationship between Mikoto and Muneyuki Uesugi, and further to question whether Mikoto's status as a forensic assistant was obtained legitimately.

Could this forensic beauty have gotten the job by serving Uesugi so well with her "cushion service"?

Minami's doubts.JPG
Mikoto Ishihara could only explain that she had come to discuss professional matters with Muneyuki Uesugi, but unexpectedly someone came to her door, so she went into the bathroom to avoid any misunderstandings.

Miss Minami was skeptical of this explanation, but at the crucial moment, Erena surprisingly supported Mikoto's statement, saying that Mikoto had indeed come to talk to Uesugi Muneyuki about something.

This dispelled some of Minami's doubts, and she then gave Ishihara Mikoto a warning.

Ms. Mikoto, Zong Xuejun's forensic assistant, you don't want to lose this hard-won position, do you?
Then do your job properly. Work is work, and life is life. Don't do things that are easy to misunderstand in the future, especially at this time.

In Minami's design, there are only three women in the house: herself, Erena, and Asuka. There is no fourth person. She can turn a blind eye to Uesugi Muneyuki occasionally having affairs outside, but bringing them home is not allowed.

After seeing Mikoto off, Minami scolded Erena again, saying, "I entrusted Uesugi to you, and this is how you watch over him? Didn't I tell you to exhaust his energy and prevent him from having any extra thoughts about flirting with other women?"

Erina felt extremely wronged. She thought to herself, "You're the one who criticized me for cheating, and you're the one who accused me of not keeping a close eye on him. What should I do?"

Therefore, both Erena and Mikoto looked somewhat unnatural at the scene today.

Uesugi Muneyuki, however, was unaware of what had happened since the previous night, and his attention was entirely focused on the scene at the Igarashi residence.

Frankly speaking, the crime scene at the Igarashi residence was poorly preserved because after the incident, Executive Director Sato brought people to search for Aiko's whereabouts, and a large group of employees had completely destroyed the crime scene.

Footprints, fingerprints, and hair are all a jumbled mess, making it very difficult to find clues using these methods.

However, after interviewing and investigating his neighbors, Uesugi Muneyuki discovered a blind spot.

"Is it here?"

Inspector Kosaka and Muneyuki Uesugi stood outside a detached house and asked the neighbors.

“That’s right. Before the incident, someone had stopped here late at night.” The neighbors nodded repeatedly. “They would observe for a long time each time, and then drive away after about an hour or two. But it was always very late, so I couldn’t see the license plate number.”

"You've been observing for a long time, haven't you?" Uesugi Muneyuki and Kosaka exchanged a glance as they asked their neighbor about the man's physique.

"About the same height as you," the neighbor gestured to Uesugi Muneyuki.

"it is good."

Uesugi Muneyuki and Inspector Kosaka stood in this position, looking towards the Igarashi residence.

Uesugi Muneyuki straightened his back, his gaze passing over the Igarashi residence, just above the wall, and seeing the small window of the Igarashi residence's bathroom and the air conditioner unit outside the window.

Air conditioner outdoor unit?

The wall surrounding this detached house is quite high. If all you can see is the air conditioner unit, what are they observing?

Uesugi Muneyuki pondered.

First of all, there are only two ways to enter the Igarashi residence: the front door and the back door.

One type of detached house is different; the front and back doors only lead into the yard. To enter the house, one needs to go through the front security door or the back sliding door.

Both locations were equipped with external alarms, and employees of the Sumitomo Mitsui Group entered while wearing the alarms on their heads.

This is also the strangest thing about this case.

So, should we climb in through the window?
That's impossible. The windows are all fitted with security bars and there are no signs of them being broken. The only problem is that the second-floor balcony window has signs of being broken from the inside. It's impossible that Kekezi broke the window from the inside to let people in, right?
So, go in through the small bathroom window?
Could someone my size really climb over such a narrow window?

Uesugi Muneyuki observed for a moment and then shook his head repeatedly.

Maybe Miss Minami could do it.

But how could Minami possibly carry someone of Igarashi Aiko's size? The man I saw was a burly fellow!

Moreover, the outdoor unit of an air conditioner has limited load-bearing capacity and will collapse!
Ok?
and many more!

Uesugi Muneyuki suddenly thought of Hironaka Mariko and his own curse.

The neighbor said yes, they were observing? Them?

A small window in the bathroom? Bypassing the front door? No alarm triggered? Attacked in your home? Feeling like someone is following you?
A terrifying thought flashed through Uesugi Muneyuki's mind like lightning.

That's right, the person who can climb over doesn't need to be a strong man, and a strong man doesn't need to climb over!

Just because I saw one person doesn't mean that only one person committed the crime! The Kanagawa police must have thought the same thing. The scene was so chaotic, with so many footprints, that everyone overlooked this blind spot.

The culprit might not be one person; there could be two! Just like me and Mariko Hironaka, one of us was responsible for tracking down the killer, and the other was responsible for triggering the contract flashback!
"I've got it!" Uesugi Muneyuki exclaimed, "I understand!"

"I know exactly how the murderer bypassed the front door and entered the Igarashi residence!"

He immediately summoned the Metropolitan Police Department personnel to the area under the air conditioner unit in the backyard of the Igarashi residence. They brought over a ladder and, sure enough, found a shoe print above the air conditioner unit!
The murderer entered the Igarashi residence through the small bathroom window above the air conditioner unit!

After entering the Igarashi residence, the murderer would unlock either the front or back door to let another accomplice in.

In other words, this case was committed by two people!

Uesugi Muneyuki immediately grasped the entire context of the case.

The two perpetrators worked together. They first followed Igarashi Aiko to her home, then selected a spot nearby to observe her for a long time. Based on the height matching that of Uesugi Muneyuki, the perpetrators observed that they could enter Igarashi Aiko's home through the small window in the bathroom via the air conditioner unit.

According to the Metropolitan Police Department's on-site test, it was almost impossible for tall and strong male detectives to replicate the feat. However, Ishihara Mikoto and another particularly short and thin patrol officer successfully entered Igarashi's home by grabbing onto a water pipe, moving a few steps upwards, and then using the air conditioner unit.

After entering the house, the murderer opened the back door and let his accomplice in. Then, the tall accomplice entered the house to lie in ambush. Since the operation took place late at night, the murderer would definitely have to lie in ambush at home for a period of time and monitor Igarashi Aiko's return home in some way.

This is why Aiko Igarashi felt uneasy when she returned home in the flashback to her death; she was indeed being watched, and the murderer was observing her return from inside the house.

It's not unusual to find unusual traces in the bathroom, since the short killer entered through there.

The reason why the glass on the second-floor balcony was broken is very likely because, during the moving process, Aiko Igarashi, who is overweight, lost her balance while struggling and bumped into the glass, which is why the glass on the second-floor balcony was found to be broken from the inside!

I understand, I understand everything!

Uesugi Muneyuki immediately shared his conclusions with the Metropolitan Police Department, while the department collected the crucial shoe print as evidence on the air conditioner unit.

This marks a breakthrough in the Yokohama case!
With just one on-site investigation, Uesugi Muneyuki achieved great success. He not only deduced that there were two murderers, one tall and one short, one strong and one thin, but also found the crucial shoe print!

Furthermore, according to Uesugi Muneyuki's deduction, the two murderers must have stayed at home for a period of time. During this time, they couldn't have done nothing, so they must have left something behind, most likely DNA from hair, saliva, and food residue!

Therefore, all we need to do is have the Mitsui employees who were here that day undergo DNA testing, and then use the process of elimination to find the DNA of the two murderers!
This result greatly excited everyone in the Metropolitan Police Department.

As expected of Uesugi, the forensic expert!

Now I've got it!
The frontline officers immediately reported the incident to the Metropolitan Police Department headquarters, which then began to arrange for DNA testing and evidence tracing.

Among them, the tracing of the shoe print's origin was carried out very quickly in the evidence tracing process.

Japanese police quickly discovered that this style of sneaker was not produced in Japan. The shoes came from a factory in Fujian, a country in which they were smuggled in. Because they were cheap and of good quality, although not as good as the original, they were very popular among young people with limited funds.

The work of tracing the source has become extremely difficult.

Since that didn't work, the Metropolitan Police Department turned its attention to DNA testing.

This matter received the full cooperation of Mitsui Properties, and all employees who had visited the Igarashi residence that day voluntarily provided their DNA to the Metropolitan Police Department.

The Metropolitan Police Department's forensic division immediately began DNA comparison.

DNA testing is a complicated process, involving five steps: DNA extraction, PCR amplification, capillary electrophoresis, data analysis and complexation, and finally, report generation.

Testing a person's DNA takes at least a day, even with overtime work. If more than 20 people are divided into three batches for testing, it will take at least three working days, and under normal circumstances, it will take at least a week due to the large number of people involved.

The Metropolitan Police Department's forensic division worked around the clock, taking shifts 24 hours a day, and finally succeeded in testing all the samples' DNA on September 24.

Finally, we've found a useful clue!

Uesugi Muneyuki was very confident about this.

However, the results left everyone puzzled.

The DNA of 15 Mitsui Properties employees, along with the DNA of Executive Director Sato and the DNA of hair and skin fragments left at the scene by the Kanagawa Prefectural Police, did not match!

What's most puzzling is that even when Aiko Igarashi's own DNA matched the DNA from her own hair and dander provided by the Kanagawa Prefectural Police, there were three mismatches in the STR data, and multiple peaks appeared.

It is generally believed that one locus could be a genetic mutation, but more than one locus can directly confirm that it is not the person in question.

Ah? ? ?
The most experienced Mikoto Ishihara only glanced at it.

"Oh no! The sample is contaminated!"

(End of this chapter)