Japan - Miyazawa family of 4 murdered, Setagaya, Tokyo, 30 Dec 2000

[FacelessPodcast]

I know police have ruled out a sexual motive as no semen was found at the scene, but I wonder if the killer made sexual advances towards either Yasuko (perhaps a tutoring student) or Niina and killed the family in revenge/rage? It could explain why the female family members were seemingly murdered more brutally than the males.

The teen boy living in the adjacent house has presumably been ruled out, but I wonder if his friends were investigated? I’m not sure when the soundproofing was installed, but it’s possible a friend may have stopped by during construction or have been told about it in passing (I.e., ‘don’t worry, we can laugh/play video games loudly because the wall is soundproofed’). A friend of the boy next door would likely also know or be familiar with the Miyazawa’s as well as the habits of the people living next door, which could explain why he felt comfortable hanging around in the house after the murders.

The boy next door was fingerprinted (the nephew of Mikio and Yasuko), yes. As for his friends, I have no idea. That's certainly a possibility. Plus we know that Yasuko used the house next door as her base of operations for giving classes.

But in terms of the soundproofing, there's absolutely no way it would've blocked out any screams. It simply wasn't that grade of soundproofing. My own sound guys went to the house and looked at it and said given the wooden frames and small amount of distance between the two houses, you likely would've heard coughing between the two houses, even if a little muffled. Let alone four people being murdered.

 

[FacelessPodcast]

Sigh. Another year, another pointless rehashing of errors and speculation from the media.

Police advised to rethink motive and opportunity in unsolved Setagaya family murder case

In a patently inauspicious start to the new millennium, Tokyo newspapers on the morning of January 1, 2001 ran front-page headlines about a horrifying fin de siecle crime: the slaying of a family of four in Tokyo's Setagaya Ward two days earlier. Mid-morning on Dec 31, the bodies of businessman…

japantoday.com

"The killer was believed to have entered through the upstairs bathroom window."
False. They're still unsure to this day whether he entered through the window -- which had no kind of fibres in it -- or the front door -- which had no bloody footprints.

"Rather than flee under cover of darkness, the killer then inexplicably lingered at the crime scene well past sunrise."
False. The only known timestamp we have for the killer's actions are 1:18am-1:23am when he logs on to the computer and then logs off. That's literally the only certain timeframe we have.

"The killer's DNA turned out to be particularly unusual as he appeared to have European ancestry on his mother's side. Other DNA markers suggested a possible link to either China or Korea."
False. As discussed above. Mitochondrial DNA analysed in the early 2000s simply could not have confirmed one way or another where his mother was from. If she was born in Portugal, that might be a lead. If it's his great grandmother x16 that's born in Portugal, that's worth jack zip. Again, the TMPD have not published this information on the DNA. There's a reason for that -- it was leaked. Therefore, his DNA suggests ABSOLUTELY NOTHING at this time.

"Some have theorized that a person of foreign origin might have less compunction to killing members of a different racial or ethnic group, but unless more facts are known, such a theory can be no more than speculation."
So, some people are racists? This is neither news nor relevant.

If the killer was economically deprived, perhaps some dispute over money with either Mikio or Yasuko Miyazawa may have moved him to seek revenge. "Among some criminals, the sense of self-victimhood from being economically deprived can inspire homicidal rage," writes Motohashi, who believes police investigators ought to change their focus to probe the money angle.
So, let me get this straight. The murderer is so angry at being poor, he slaughters an entire family... but leaves behind money in their house. Hmm, ok then...

"But thieves," Motohashi contends, "prefer to target houses that are easy to break into, not necessarily those that appear wealthy."
Why the hell would a thief target a family house at a time when it was obvious the family would be home? The lights were on and it was leading up to the holiday period. This makes zero sense.

"Since the crime experts who analyze the Miyazawa case enjoy above-average economic status themselves, they may not be capable of fully grasping the psychology of a desperately needy person reacting on the spur of moment," Motohashi writes.
With all due respect to Mr. Motohashi, I've spoken personally to some of those involved in the investigation of the case and I don't think their "economic status" in any way affected this case. And frankly, the idea of someone being so poor they end up slaughtering an entire family is among the more stupid theories I've heard.

 

[Frankie Hellis]

I wonder if they checked the enrollment at the local college. If, and I realize this is not known as a definite, but if the killer spent time napping in addition to his eating the ice cream, I tend to think it could have been someone who did not have the luxury of alone time. They already think he was young, so to me it fits that he either lived with roommates or family and was experiencing some kind of freedom by lingering. Otherwise, what murderer would not get the hell out of dodge asap?

 

[Frankie Hellis]

Sigh. Another year, another pointless rehashing of errors and speculation from the media.

Police advised to rethink motive and opportunity in unsolved Setagaya family murder case

In a patently inauspicious start to the new millennium, Tokyo newspapers on the morning of January 1, 2001 ran front-page headlines about a horrifying fin de siecle crime: the slaying of a family of four in Tokyo's Setagaya Ward two days earlier. Mid-morning on Dec 31, the bodies of businessman…

japantoday.com

"The killer was believed to have entered through the upstairs bathroom window."
False. They're still unsure to this day whether he entered through the window -- which had no kind of fibres in it -- or the front door -- which had no bloody footprints.

This is interesting because the photos from 2000 do not show a reasonable way in through a second story window, IMO. More recent photos, including from 2022 show the tree in the back grown high enough for this to make sense, but not back then. I thought they found footprints and broken branches though?

 

[Frankie Hellis]

Lastly, do you have or have you seen the autopsy reports? What do you make of the wound on Mikio’s thigh? Apparently it is in an upward direction, which does not fit with the theory he was attacked from above and pushed down the stairs.

 

[FacelessPodcast]

I wonder if they checked the enrollment at the local college. If, and I realize this is not known as a definite, but if the killer spent time napping in addition to his eating the ice cream, I tend to think it could have been someone who did not have the luxury of alone time. They already think he was young, so to me it fits that he either lived with roommates or family and was experiencing some kind of freedom by lingering. Otherwise, what murderer would not get the hell out of dodge asap?

I'm almost certain they will have looked at all educational facilities in the local area. The kids were enrolled in different schools as I understand and the mother ran a cram school out of her sister's house next door.

As for spending time in the house, this crazy risk has always puzzled me. I can only conclude that:

1) he was mentally unsound and simply didn't understand the risks. But I tend to doubt that considering he patched himself up so obviously displayed some self-preservation and fled the scene eventually, never to turn himself in.

2) he simply figured the risk to leaving the house while bleeding was greater than getting his strength back / patching himself up in the house. He also could've been in shock or not thinking straight. Given his blood and faeces were both analysed, we know he wasn't under the influence of drugs.

 

[FacelessPodcast]

This is interesting because the photos from 2000 do not show a reasonable way in through a second story window, IMO. More recent photos, including from 2022 show the tree in the back grown high enough for this to make sense, but not back then. I thought they found footprints and broken branches though?

The window would've definitely been a tight fit. If you go back to the start of this thread, you can see some clearer images of it. It would've been challenging but not impossible. And it was actually the fence between the back of the house that he would've likely perched on, not the tree.

 

[FacelessPodcast]

Lastly, do you have or have you seen the autopsy reports? What do you make of the wound on Mikio’s thigh? Apparently it is in an upward direction, which does not fit with the theory he was attacked from above and pushed down the stairs.

I do recall looking at the autopsy reports but it was years ago and I haven't been able to find them since. Are you able to link? That would be great.

The upward stab in the thigh could either be sustained after he was prone at the bottom of the stairs and the killer was simply trying to finish him off.

OR, the theory with the window is wrong from the start and the killer entered from the front door. As I posted on the Japan Today article, we simply don't know how he got in.

If he went through the window, he managed to leave ZERO fibres in the window frame. Then again, there was no blood around the front door. So unless he cleaned himself throughly before leaving the house, somehow while standing at the front door, then this is something of a paradox? Because there was a lot of blood pooling at the bottom of the stairs and the top (where Mikio, and the mother and the daughter died respectively).

 

[Omega Man]

Looking at the floor plan, could the killer have entered via the garage door? I know some people just park their car and let the gate automation do it's work without checking if someone snuck in (grage door automation is usually quite slow for safety reasons).

 

[citizen_sleuth]

I do recall looking at the autopsy reports but it was years ago and I haven't been able to find them since. Are you able to link? That would be great.

The upward stab in the thigh could either be sustained after he was prone at the bottom of the stairs and the killer was simply trying to finish him off.

OR, the theory with the window is wrong from the start and the killer entered from the front door. As I posted on the Japan Today article, we simply don't know how he got in.

If he went through the window, he managed to leave ZERO fibres in the window frame. Then again, there was no blood around the front door. So unless he cleaned himself throughly before leaving the house, somehow while standing at the front door, then this is something of a paradox? Because there was a lot of blood pooling at the bottom of the stairs and the top (where Mikio, and the mother and the daughter died respectively).

Is it possible the killer used the shower/bath before leaving? I believe there were documents in the tub, could the killer have thrown them in there after he washed himself off?

 

[dotr]

I wonder if they checked the enrollment at the local college. If, and I realize this is not known as a definite, but if the killer spent time napping in addition to his eating the ice cream, I tend to think it could have been someone who did not have the luxury of alone time. They already think he was young, so to me it fits that he either lived with roommates or family and was experiencing some kind of freedom by lingering. Otherwise, what murderer would not get the hell out of dodge asap?

Almost has me wondering about male prostitution in Japan and if the perp could be one of them, maybe it was the ice cream eating (easy digest) that prompted that thought. fwiw, imo, speculation.

‘Boys for Sale’: the dark world of Japan’s gay prostitution

‘Boys for Sale’: the dark world of Japan’s gay prostitution

www.scmp.com

 

[Frankie Hellis]

I do recall looking at the autopsy reports but it was years ago and I haven't been able to find them since. Are you able to link? That would be great.

The upward stab in the thigh could either be sustained after he was prone at the bottom of the stairs and the killer was simply trying to finish him off.

OR, the theory with the window is wrong from the start and the killer entered from the front door. As I posted on the Japan Today article, we simply don't know how he got in.

If he went through the window, he managed to leave ZERO fibres in the window frame. Then again, there was no blood around the front door. So unless he cleaned himself throughly before leaving the house, somehow while standing at the front door, then this is something of a paradox? Because there was a lot of blood pooling at the bottom of the stairs and the top (where Mikio, and the mother and the daughter died respectively).

I have not seen the autopsy reports. That is why I am asking you! Lol. To my knowledge, they are not available, but I would love to see them if they are, in fact, available somewhere.

The lack of blood (to me) is not an incredible feat, as he came in clean and likely cleaned up after the crime, so he also left devoid of blood.

I’d have to see some close ups of the window to comment on fibers, or the lack thereof. If the window didn’t have any sharp areas, and the killer wore a smooth coat, I am not sure how unusual it would be to not leave fibers. Moreover, it was a holiday skeleton crew who originally assessed the scene, so it could be possible fibers were missed. He could have entered via the window since we know he was quite thin. I do think Rei was killed first, which is a point for the window being the entry point, but I am not married to that theory if there were more compelling evidence of another entry point to come to light.

I am just as interested in getting into the killer’s mind. Why did he do what he did re: documents, ice cream, length of time in the flat, etc.

 

[Lexiintoronto]

I'm almost certain they will have looked at all educational facilities in the local area. The kids were enrolled in different schools as I understand and the mother ran a cram school out of her sister's house next door.

As for spending time in the house, this crazy risk has always puzzled me. I can only conclude that:

1) he was mentally unsound and simply didn't understand the risks. But I tend to doubt that considering he patched himself up so obviously displayed some self-preservation and fled the scene eventually, never to turn himself in.

2) he simply figured the risk to leaving the house while bleeding was greater than getting his strength back / patching himself up in the house. He also could've been in shock or not thinking straight. Given his blood and faeces were both analysed, we know he wasn't under the influence of drugs.

The killer in this case reminded me of Orsolya Gaal’s murderer who also injured his hand while stabbing her, spent time in her home tending to his wounds and cleaning up the crime scene. All the while he knew her teenage son was asleep in an upstairs bedroom.

I think this killer tried to patch his injury and then went to the freezer for something cold to apply to it, and used the icecream. I believe that as each small container melted, he just drank it (he apparently didn’t use a spoon).

My impression is that he was in the home to take Niina, but I’m not sure why she was killed. Maybe she was inadvertently injured in the initial attacks, and then he didn’t want her to survive and be able to ID him(?)

There was in interval between when the mother and Niina were first injured to when they were killed from what I understand. I don’t yet know if there’s evidence that he was able to access the attic where they were. If there’s not, he may have had to wait it out for them to come down on their own.

 

[Lexiintoronto]

What they say officially is that they will not give up. The detective I've been talking to at length is now retired so I want to make clear that his opinions were only his and not that officially of the TMPD.

That said, it does seem as if DNA and evolving technology is the way forward. So, it's hard to answer but I do think there is a degree of positivity. The latter episodes will shed more light on this and my own thoughts about what they've done, where we go from here. Thanks for listening, ck!

I’ve only listened to the first episode and it’s excellent. You’re very respectful to everyone that was impacted by the crime.

 

[citizen_sleuth]

世田谷一家殺害事件 遺族の思い (Thoughts of the bereaved family of the Setagaya family murder case) - NHK
<translated and snipped>
Yasuko's two children were also attached to Irie.

It was Irie's duty to take her niece Nina to elementary school.

She says that she was a child who understood other people's feelings.

She suffered from rheumatoid arthritis, and when she went out with Irie's mother, who was suffering from the pain, she was a gentle girl who said, "Grandma, you can hold on to my shoulder."

[...]

In addition to deepening her studies of grief care and working as a lecturer at the Institute of Grief Care at Sophia University, Irie pondered why she could not talk about her grief and what it means to talk about and face grief, and disseminate that awareness in books and lectures.


A scene from "Suho's White Horse" drawn by Nina-chan


Left: Rei-kun's birthday, Nina-chan right: Rei-kun's 2nd birthday

Broadcast Human Rights Commission Decision No. 61, "Appeal to the Setagaya family murder special program," Recommendation (September 12, 2016)
<translated, edited for readability, & snipped>
On Sunday, December 28, 2014, TV Asahi broadcasted "The Moment of the Century & Unsolved Incidents in Japan." The special, "The Setagaya Family Murder Case," was broadcast as a three-hour year-end special program (hereinafter referred to as "this broadcast"). [The Setagaya family murders], which occurred late at night on December 30, 2000, is still unsolved Taking up the [Miyazawa] family murder case, a former FBI investigator will profile the criminal. It was content. The family that the petitioner, who is the sister of one of the victims, denied it was a crime by an acquaintance who had a strong grudge against him.

[...]

In order to find out who the culprit is, [former FBI profiler] Mark Safarik apparently interviewed An Irie, the bereaved family of the victim, and others, was broadcast. Irie was the older sister of Yasuko Miyazawa, who was murdered, and lived next door at the time of the incident. In the program, the former investigator said, "At that time, I was Japanese in my mid-twenties, I knew the Miyazawa family, and I was mentally ill. [The perpetrator is] a person who holds a strong grudge against him, who has a problem with his wife."

[...]

In addition, TV Asahi reported that the petitioner said, "I feel that my sisters did not hold a grudge against me.
There were no personal troubles, money troubles, or anything like a relationship between men and women."

[...]

The petitioner is Yasuko's older sister. At the time of the incident, she lived next door to the victim's family. [Her] mother
[...] was also the first to discover the incident. About half a year after the incident, at the request of the investigative authorities, [there was] "work to investigate malice" to see if there was a person close to her who had a grudge against her sister's family. During this process, the petitioner had a strong resentment toward his family [and] reject[ed] the view that the crime was committed by an acquaintance.

世田谷一家殺害事件、現場の家を公開　遺族「壊せない」- The Setagaya family murder case, the site of the scene released: Bereaved family "cannot be destroyed" - Asahi Shimbun (January 18, 2020)
Included in the article is actual video from the inside of the house.

［世田谷一家殺害２０年］＜上＞照合した指紋は５０００万件、今なお増える犯人資料 - 20th anniversary of the Setagaya family murder: 50 million fingerprints collated, still increasing - Yomiuri (December 12, 2020)
It was the criminal's fingerprints that made the Special Investigation Headquarters shine. Investigators dubbed him "Butabana" because of the swirly pattern on his thumbs, which looked like a pig's nose. The culprit also had a wound on his hand, leaving a bloody "stain".

"There aren't many incidents that have Hoshi's [the criminal's] fingerprints from the beginning. I thought, 'I can do it,'" a former investigator who participated in the initial investigation looks back.

[...]

In the evening of the day after the incident, a station employee was treating a man with an injured hand at Tobu Nikko Station in Nikko City, Tochigi Prefecture. However, the investigation was put on the back burner, saying, "There's no way you can get on the train while bleeding.'' About 10 months later, investigators headed to the scene. The man who was treated for his wounds has not yet been identified.

A former investigator who was a member of the Special Investigation Headquarters revealed, "What we detectives are most afraid of is that someone who listens to the story and decides 'not the culprit' is later found out to be the culprit and is arrested." He continued: "It is possible that investigators at the scene thought, 'This time, as long as they take the fingerprints, they won't overlook the criminal,' and the questioning and investigation of friendships were insufficient."

3D rendering of the area produced by TMPD

 

[Omega Man]

世田谷一家殺害事件 遺族の思い (Thoughts of the bereaved family of the Setagaya family murder case) - NHK
<translated and snipped>

Note how some areas of the park are elevated and provide good view of the house interior, especially in the evening and at night when the lights inside are on.

 

[citizen_sleuth]

This website supposedly has excerpts from contemporary news reports. I am unable to verify the authenticity of the content, but I will repost them here as I found some of the content interesting. A summary of key takeaways:

• Yasuko taught English and math to roughly 45 elementary and junior high school students. She also employed several part-time teachers as assistants. (Sankei Shimbun, 01/10/2001)
• Mikio's thigh had a deep diagonal stab wound which was could not have been made by the kitchen knives in the house (Sankei Shimbun, 01/04/2001)
• The long-sleeved shirt believed to have been worn by the killer was found in the living room on the second floor, covered in blood. It is believed the shirt was originally gray, but turned white due to excessive washing (Asahi Shimbun, 01/20/2001)
• 60 bloody footprints were found at the house, mainly in the living room on the second floor (Asahi Shimbun, 01/13/2001)
• Police interviewed store clerks working at the stores where the items left behind by the killer may have been purchased, but none of them reported seeing anything suspicious (Asahi Shimbun, 01/20/2001)
• TMPD investigated around 50 cases of men with injured hands who were treated at area hospitals after the murders, but ruled out all of them as suspects (Sankei Shimbun, 01/28/2001)

急転解決目指し総力戦　世田谷一家殺害事件 "All-out war aimed at resolving the sudden turn of events Setagaya family murder case" - Sankei Shimbun (January 28, 2001)
The investigative team for the case is about 100 detectives centered on the two homicide investigation teams of the Metropolitan Police Department's First Investigative Division. The initial number of 80 was increased to 20 to confirm suspicious person information from the general public and hospitals. However, the fifty-odd cases of information from the hospital regarding "a man with an injured hand" have all been found to be unrelated to the case, and the amount of information received is dwindling.

遺留品はいずれも現場周辺で入手可能　一家４人殺害事件 "All items left behind can be obtained around the scene Murder case of a family of four" - Asahi Shimbun (January 20, 2001)
In the living room on the second floor of Mr. Miyazawa's house, an L-sized sweatshirt with blood on it, believed to have been soaked in the victim's blood, was left unattended. White with purple arms[,] it was originally gray, but after washing it many times, it turned white.

An apparel sales company in Yamanashi Prefecture imported from China for young people and sold a total of 2,300 pieces in Suginami Ward and Katsushika Ward in Tokyo since August last year. The manufacturer's casual shop is located in a supermarket near Ogikubo Station on the JR Chuo Line, six kilometers north of Mr. Miyazawa's house. It is said that the store only sold a few pieces of the same size with purple arms.

[...]

None of the store clerks who sold these clues remembered the faces of the customers, and the buyers could not be identified. The investigative headquarters is investigating whether the criminal lives in the area around the scene or has a familiarity with the area.

４人でなべ料理のあと襲われる　東京の一家殺害 - "Tokyo family murdered after four people cook in a hot pot" - Asahi Shimbun (January 14, 2001)
On the 14th, the investigative headquarters of the Metropolitan Police Department Seijo Police Station found that fragments of the Yanagiba knife, which is believed to have been brought in by the criminal, were left on the 2nd and 3rd floors where they were attacked. Judging from the contents of their stomachs, it is believed that the four of them ate a hot pot meal on the night of the incident. According to the investigative headquarters, [Mikio] Miyazawa was the first to be attacked, as he was awake in the middle of the night after dinner, and then Yasuko and her two children.

犯人はテニスシューズをはいていた？　世田谷の一家惨殺 "Was the killer wearing tennis shoes? Murder of a family in Setagaya" - Asahi Shimbun (January 13, 2001)
According to an investigation, there were about 60 bloody footprints, mainly in the living room on the second floor of Mr. Miyazawa's house. In addition to the marks of the mother who found the four bodies, one type of shoe mark that seems to belong to the culprit was found.

手にけがの男　浮上/一家４人殺害　以前出入りの22歳 "A man with an injured hand surfaced, murdered a family of four, a 22-year-old who used to come and go" - Sankei Shimbun (January 10, 2001)
After graduating from the Faculty of Agriculture at the University of Tokyo, Mikio was involved in animation production, etc., and since 1998 he has been working at a British consulting company. Yasuko opened a Kumon-style classroom at her home and taught three subjects in English and mathematics to about 45 of her elementary and junior high school students. She employed several part-time teachers as assistants.

第3の凶器存在？　一家4人殺害 "Existence of a third weapon? Family of four murdered" - Sankei Shimbun (January 4, 2001)
According to the investigation so far, Mikio, his wife Yasuko (41), and his eldest daughter Nina-chan (8) have more than a dozen cuts, mainly on the upper body, including the throat. In the kitchen, there are two knives: a brand new yanagiba knife, which is believed to have been brought in by the culprit, and a bunka knife that belonged to Mr. Miyazawa's house.

As a result of a judicial autopsy, it was found that Mikio's thigh had a deep diagonal stab wound, deeper than the two remaining kitchen knives, and the shape did not match.

For this reason, the investigative headquarters believes that the criminal attacked the Miyazawa family with a sharp and long weapon in addition to a kitchen knife.

 

[Frankie Hellis]

Finally, as for the Buzzfeed article linked at the top, it was a little disappointing.

I have seen many articles suggest the killer was there until after 10AM in the morning due to the computer activity thought to have happened as a result of mouse movement. My question is this: I read that the computer was not on when authorities arrived. I also read elsewhere that the computer‘s electrical cord had been taken. How could any mouse movement have affected the computer if either of these statements were true?

I also now have another question: Was there believed to have been a third knife, based on Mikio’s wounds?

 

[FacelessPodcast]

Looking at the floor plan, could the killer have entered via the garage door? I know some people just park their car and let the gate automation do it's work without checking if someone snuck in (grage door automation is usually quite slow for safety reasons).

As far as I know, the killer never enters the garage according to the TMPD. How they know that, I'm not sure. Presumably the door to it was locked? Or the sensors showed that the shutter never raised?

 

[FacelessPodcast]

Is it possible the killer used the shower/bath before leaving? I believe there were documents in the tub, could the killer have thrown them in there after he washed himself off?

I've wondered this too. Basically, I think it's possible but the issue is that there were a lot of blood pools throughout the house. If the bathroom was on the second floor and next to two bodies (Niina and Yasuko), how does he avoid them while getting in and out? Plus there was no blood, as I understand it, at the front door. So he would've needed some way to clean his shoes at the front door. And most likely washed up his footprints leading up to it.

Not impossible, of course. But given he made zero effort to hide any of his actions or evidence, it would be odd to suddenly care if the police could tell his point of entry/exit.