Tokyo Unnatural Forensics

Chapter 396, The Mystery of the Massacre

The Toshima Ward family annihilation case attracted great public attention at the time. The horrific scene shocked even the experienced detectives of the First Investigation Division. The Metropolitan Police Department immediately established a special investigation headquarters to begin investigating the case step by step.

They made a discovery very quickly.

On the evening of February 23, the perpetrator (presumably one person) took advantage of the increased activity and noise from neighbors during the holiday period to quietly sneak into the small backyard of the Sato family. He/she may have climbed the low fence or used the yard's debris as cover.

The killer lurked in the backyard tool shed for a considerable period of time (several hours), leaving behind clear muddy footprints (severely worn heels), a flattened empty energy drink can (Red Bull, no DNA/fingerprints), and several strands of dark brown/black synthetic fibers (from clothing or a backpack).

Evidence suggests that the perpetrator observed a family of four celebrating a long weekend inside the house through a gap in the curtains that were not fully drawn. Minor new scratches and a blurred palm print were found on the back windowsill at the scene.

In other words, the murderer had been observing the Sato family for a long time without them noticing.

This is truly chilling.

Uesugi Muneyuki continued:

"After the whole family fell asleep (around 1:30 a.m.), the murderer came out of the tool shed and used a sturdy nylon climbing rope found in the tool shed. The rope was not a Sato family item; it was recently purchased and was from a common brand. He strangled the guard dog (a small Shiba Inu) to prevent it from barking. The dog's body was then abandoned in a corner of the backyard."

The killer then used a paving brick found in the backyard to smash the glass sliding door connecting the living room and kitchen, gaining entry into the house. Broken glass was scattered all over the floor, but the killer seemed very familiar with the Sato family's interior layout, deliberately avoiding the main walking paths.

The assailant first entered the master bedroom on the first floor and used an ice pick with a specially serrated blade, which he was carrying, to repeatedly and fatally stab Kenichi and Miwako while they were asleep, mainly in the chest and abdomen. Both died almost instantly, with little chance to resist. There was a large amount of blood splattered at the scene.

"Then, the murderer went up to the second floor and entered Shota's room. Shota may have been awakened by the noise downstairs and there were signs of a brief struggle. In the end, the murderer used the same ice pick to stab Shota to death. The wounds were concentrated on his neck and chest. Riko may have been awakened by the sound of the struggle and ran to the stairwell to check. The murderer caught up with her at the stairwell and stabbed her to death with the ice pick."

If the above could be considered a typical family annihilation case, then the Metropolitan Police Department's subsequent investigation revealed the source of the utter baffling mystery.

The perpetrator did not leave the scene immediately after committing the crime!

He went into the kitchen on the first floor, took out a bottle of Korean Qinglu sake, and ate and drank it openly with the oranges on the table. He even tried to cook instant noodles and heated up some vegetables from the refrigerator in the microwave to eat with it!
A feast was held at the crime scene?

Japanese police still don't understand the killer's logic; he even deliberately left behind saliva and glove prints.

After eating and drinking his fill, the murderer calmly washed his hands. Even at this point, he didn't leave. Instead, he turned on the video recorder, took out a carefully printed family gathering videotape of the Sato family, and sat on the sofa watching it for a full 45 minutes using the remote control. Even when the prompt to change the disc came, he was still somewhat unsatisfied. He took a roll of bandages and bandages from the first-aid kit and left a Trek size 42 shoe print nearby.

Afterwards, the murderer seemed to finally intend to leave. He took more than 10 yen in cash from the homeowner's drawer, but didn't even look at the woman's jewelry and bankbook. It is worth mentioning that he specifically took the man's Zippo lighter (it was later discovered that this item was missing during the inspection).

Ultimately, the killer left the ice pick on the table and deliberately arranged oranges in the shape of the four deceased family members. Around 4 a.m., the killer left through the broken glass door, crossed the yard, and climbed over a relatively concealed spot in the backyard wall. A size 42 Trek shoe print, identical to the one inside the house, was left on the dirt ground of the alley outside the wall, but quickly disappeared in the direction leading to the main road. It was a holiday morning, and there were almost no witnesses on the road, nor was there much surveillance footage.

Japanese police were initially very confident of solving the case because the perpetrator had left behind so much evidence and clues.

The bloodstains were identified as type A blood. Y-chromosome DNA (Y-STR) of the same unknown male was extracted from the skin tissue/bloodstains under Shota's fingernails, the saliva on the glass from which he drank shochu, and the mixed DNA on the ice pick handle. Analysis showed that this DNA had rare mixed characteristics of East Asian and Caucasian races (his paternal ancestry may have been of European descent).

The site contained a clear print of a size 42 "TrekMaster" limited edition sneaker.

From the murder weapon to the rope to the fingerprints to the bloody handprints and the whole bunch of physical evidence he touched.

In addition to these, there are a few other key points.

First of all, the murderer seemed to be very familiar with the Sato family, not only observing them for a long time but also knowing their home environment like the back of his hand.

Secondly, the perpetrator's behavior was very strange. Normally, any perpetrator would leave the scene immediately after committing a crime. However, he not only didn't leave, but stayed for one or two hours, treating the place like his home, eating and drinking lavishly, and even showing interest in watching a family gathering video he had previously recorded—a video that, to outsiders, is usually a long and meaningless resource. Finally, the perpetrator's behavior was also strange. He didn't take nothing, but he didn't seem to be after money either. He only took the 10 yen in cash from the drawer, ignoring the bankbooks and jewelry. According to police investigation, the perpetrator didn't deliberately search the place. In fact, there were at least two other places in the house where there was a considerable amount of cash, but the perpetrator didn't search them since he wasn't in a hurry to leave.

As mentioned earlier, Japanese police are best at finding clues through interpersonal relationships. However, after investigating the Sato family, the relationships within the izakaya were very complicated. Customers came and went, and the staff changed every month, so there was no accurate list at all. However, although the Sato family occasionally had conflicts with their neighbors, their interpersonal relationships were relatively simple.

A revenge killing? There were indeed minor conflicts in the operation of the izakaya, but it was far from enough to wipe out an entire family. Shota and Riko also had no unusual interpersonal conflicts. A thorough investigation of all social relationships revealed no suspect with a motive, the opportunity, or physical evidence matching the characteristics of the crime (especially mixed-race DNA).

Robbery and murder? Only a small amount of cash was taken, and no other valuables were touched, which does not fit the typical robbery-murder scenario!
Random killing? Psychotic killing? Psychopathic killing? The perpetrator's strange behavior, such as lingering at the scene for a long time, watching home videos, and eating, could indeed indicate a mental illness. However, such perpetrators usually have a tendency to commit serial crimes. After this case, no other cases with completely identical methods and targets have occurred in Toshima Ward or even Tokyo.

Hired killing is even more absurd; the killer's strange behavior at the scene (lingering, watching videos, eating) doesn't fit the calm and efficient style of a professional assassin. Furthermore, no evidence of an employment relationship was found. The mixed-race DNA also increases the difficulty of random hiring.

Therefore, the Metropolitan Police Department found that it was impossible to deduce the killer based on any reasonable motive.

Then there is the physical evidence.

More than 5000 pairs of these Trek shoes have been sold throughout Japan, but tracing their origin has failed.

The ice picks were found to have originated from overseas, with an unknown brand, and the tracing of their origin failed.

The dark blue waterproof nylon fabric patch, after investigation, may have come from a high-end outdoor jacket, fishing/nautical jacket, workwear in specific industries (such as transportation and construction), or even a custom-made item. The manufacturer could not provide an accurate sales list.

At this point, the only remaining clue was DNA.

However, Japan only collected DNA from convicted criminals, resulting in a limited sample size and coverage. The general population (especially those of foreign descent) was not included on a large scale, and no matches were found in the databases of several countries accessed through Interpol. This means that the perpetrator or their known paternal male relatives (such as brothers, uncles, cousins, etc.) had been entered into the system for other crimes.

Following this, the police invested significant resources to conduct a focused investigation based on mixed-race characteristics, targeting South Korean/North Korean communities in Japan (due to clues about soju), personnel and descendants of US military bases in Japan, and Japanese-European/Japanese-American mixed-race individuals.

Still nothing.

This completely stumped the Japanese police, who had no choice but to publicly solicit clues from the public.

Some people said they had seen a similar man near Sato's residence, but couldn't remember what he looked like.

Some say the massacre of the Sato family may be related to the Aum Shinrikyo cult, but the police investigation doesn't match up the timeline or the people involved.

Some have suggested that the perpetrator might be a highly intelligent criminal who deliberately misled the police with the clues and actions he left behind. However, the Japanese police do not agree with this view—no highly intelligent criminal would be foolish enough to leave their blood, saliva, fingerprints, or DNA at the scene.

The investigation into the case suddenly became a mystery, and the whole country was discussing it intensely, even attracting the attention of the Prime Minister. After several months of investigation, 55000 police officers were mobilized to search for 2200 suspicious men in Tokyo, but no suspicious persons were found. Japanese police even went to the U.S. military base in Japan to investigate and collect DNA, but still found nothing. In the end, the murderer was given the nickname "Ikebukuro Ghost".

Now, 15 years have passed. Although the Metropolitan Police Department has never given up on the investigation of this case, it is obvious to everyone that it is unlikely to be solved. After 15 years, it is almost impossible to trace the source of physical evidence. The murderer may have disappeared or died from his injuries or settled overseas. The key witnesses have blurred memories or have passed away. The key physical evidence has been destroyed. It will be difficult to find out the source of the case!

After the case was finished, we moved on to the usual interactive session.

Promotion ceremony? Mai-senpai had some doubts in her heart, wondering if this case was related to the other world?
"Junior, what are your thoughts? As a legendary forensic pathologist, what are your opinions on the Ikebukuro ghost visitor and the Toshima Ward family massacre?"

Uesugi Muneyuki nodded.

"Well, regarding this case, I think..."

(End of this chapter)