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

[Sillybilly]

Thanks to @Incoherent for the images. Tricia has approved them as is (without links).

 

[Incoherent]

There were protective casings on what I assume to be blood stains, outside of the Irie house too.
I hadn’t seen this angle before or in enough quality to spot them.
This perhaps means the ones in the genkan of the Miyazawa house, on their steps, and outside the Irie’s, are all Haruko’s after she ran back. We haven’t had any reports on what or whose they are.

But would the blood in the house still be wet enough to cause this almost 12 hours later? I suppose so.

Thoughts?

 

[Charlot123]

View attachment 623110
There were protective casings on what I assume to be blood stains, outside of the Irie house too.
I hadn’t seen this angle before or in enough quality to spot them.
This perhaps means the ones in the genkan of the Miyazawa house, on their steps, and outside the Irie’s, are all Haruko’s after she ran back. We haven’t had any reports on what or whose they are.

But would the blood in the house still be wet enough to cause this almost 12 hours later? I suppose so.

Thoughts?

It coagulates. However, if there was raining outside, so her shoes were wet, and there was a lot of blood inside, it could happen, to a degree. My first question would be, was any of the adults in the house prescribed anticoagulants/aspirin for a specific condition? That could explain more.

 

[Lalalacasbah]

View attachment 623110
There were protective casings on what I assume to be blood stains, outside of the Irie house too.
I hadn’t seen this angle before or in enough quality to spot them.
This perhaps means the ones in the genkan of the Miyazawa house, on their steps, and outside the Irie’s, are all Haruko’s after she ran back. We haven’t had any reports on what or whose they are.

But would the blood in the house still be wet enough to cause this almost 12 hours later? I suppose so.

Thoughts?

I suppose if she stepped in a pool area it might still be tacky or sticky. I imagine the girls had a pool around them

If thin and spread out it would likely dry but maybe a thick pool of blood would too? Not sure. There would be an awful lot of blood so might not dry that quick?

 

[Incoherent]

It coagulates. However, if there was raining outside, so her shoes were wet, and there was a lot of blood inside, it could happen, to a degree. My first question would be, was any of the adults in the house prescribed anticoagulants/aspirin for a specific condition? That could explain more.

I would expect that since this is Japan she took her shoes off in the entrance, hence the adult bloody foot (not shoe) print on the second floor. From the entrance the house looked a mess but she wouldn’t have seen any bodies yet. Perhaps she didn’t put them back on as she ran out again and that’s what has been left at the house entrances.

 

[Incoherent]

I suppose if she stepped in a pool area it might still be tacky or sticky. I imagine the girls had a pool around them

If thin and spread out it would likely dry but maybe a thick pool of blood would too? Not sure. There would be an awful lot of blood so might not dry that quick?

From crime scene photos yes the blood around Yasuko and Niina was significant, so perhaps it was still transferable to a foot or a shoe even almost 12 hours later.

 

[SteveL]

View attachment 623110
There were protective casings on what I assume to be blood stains, outside of the Irie house too.
I hadn’t seen this angle before or in enough quality to spot them.
This perhaps means the ones in the genkan of the Miyazawa house, on their steps, and outside the Irie’s, are all Haruko’s after she ran back. We haven’t had any reports on what or whose they are.

But would the blood in the house still be wet enough to cause this almost 12 hours later? I suppose so.

Thoughts?

Obviously, the number one question I have is "Whodunnit??" But my SOLID number 2 is, "Wazz going on next door?' Why did 'An Irie' and the rest of the family stone cold leave Yaruko in the house next door to live alone for all these years?

 

[Charlot123]

I am not sure that the killer went as far as altering fingerprints, but apparently, it is not impossible. I thought it was, but technology changes. All the more reason to push for full-scale genetic criminology in Japan.

Forensic Spotlight: Altered Fingerprints - A Challenge to Law Enforcement Identification Efforts | FBI: Law Enforcement Bulletin

Criminals use a variety of methods to alter their fingerprints, presenting challenges to law enforcement.

leb.fbi.gov

 

[SHADOWW7]

I’m not an expert at all — I only recently started studying cold cases and I’m still learning how to connect puzzle pieces properly. But after going through the Setagaya case details again, one small theory made some sense to me, so I’m sharing it humbly in case it adds anything.

If the newer DNA interpretation is correct and the killer was actually in his 30s, it fits a certain pattern: not a reckless teenager, but also not a trained professional — someone capable of basic planning but still careless in major ways.

One thought is that his clothes may have gotten completely soaked in blood during the attack. That would explain why he left behind items like the jacket, hat, scarf, and gloves. But he obviously couldn’t walk out without clothes, so maybe he grabbed something from the Miyazawa family wardrobe just to escape the house.

Ill-fitting or unfamiliar clothing could attract attention, though. That might be why he took the small amount of cash — not as theft, but to buy cheap clothes quickly or pay for transport, then dump whatever Miyazawa clothing he had on.

It doesn’t address every part of the case (like the sand, bathroom behaviour, ice cream, etc.), but as a single thread, this idea seemed somewhat practical to me.
Just sharing it as my personal theory — please don’t copy or repost without credit.

And if anyone here feels this line of thinking makes sense (or notices weak points or missing angles), please feel free to add on or point it out. I’m still learning, and any corrections or additions would actually help improve the theory.


Just sharing it as my personal theory — please don’t copy/repost without credit.

 

[Eliver]

I’m not an expert at all — I only recently started studying cold cases and I’m still learning how to connect puzzle pieces properly. But after going through the Setagaya case details again, one small theory made some sense to me, so I’m sharing it humbly in case it adds anything.

If the newer DNA interpretation is correct and the killer was actually in his 30s, it fits a certain pattern: not a reckless teenager, but also not a trained professional — someone capable of basic planning but still careless in major ways.

One thought is that his clothes may have gotten completely soaked in blood during the attack. That would explain why he left behind items like the jacket, hat, scarf, and gloves. But he obviously couldn’t walk out without clothes, so maybe he grabbed something from the Miyazawa family wardrobe just to escape the house.

Ill-fitting or unfamiliar clothing could attract attention, though. That might be why he took the small amount of cash — not as theft, but to buy cheap clothes quickly or pay for transport, then dump whatever Miyazawa clothing he had on.

It doesn’t address every part of the case (like the sand, bathroom behaviour, ice cream, etc.), but as a single thread, this idea seemed somewhat practical to me.
Just sharing it as my personal theory — please don’t copy or repost without credit.

And if anyone here feels this line of thinking makes sense (or notices weak points or missing angles), please feel free to add on or point it out. I’m still learning, and any corrections or additions would actually help improve the theory.


Just sharing it as my personal theory — please don’t copy/repost without credit.

The fact the killer's clothes were covered in blood and that he took some clothes from within the house has been already confirmed by the police and it is also a known fact: the killer took some of Mikio's clothes (a sweater or possibly something else I'm forgetting right now) and the police never found them again.

Nothing has ever been linked to this and the police never commented again so it must mean there was no follow up on it.

As per the money being taken is anyone's guess really, it could be argued it was for this and that but ultimately there is no definitive proof about any angle.

 

[rvlvr]

Apologies for the radio silence, thread friends. I promised I'd return with news when/if there was any. As such: an offer has been made from a major audio platform for another Miyazawa murder podcast written / hosted by your humble narrator.

All being well, we should be out in time for the 25th anniversary of the murders.

Was a big fan of this podcast but never thought to look the case up on here, is this still in the works? Hopefully it’s progressing well, it’d be great to get more quality content on this case.

Very difficult crime to make sense of. My hunch is the perpetrator was very young and/or very mentally unwell. I think even in 2000 a killer being so careless as to leave a lot of DNA at a crime scene was understandable, particularly in a country with very restrictive DNA laws, but to leave fingerprints all over the place? Your common or garden criminal would surely be too clued up to be that lax - unless, I suppose, they thought there was no chance their prints could ever be matched, such as if they were leaving the country? Though if the perp had a military connection they’d no doubt have been fingerprinted at some point, which you’d think would make them a little more forensically aware? But maybe they just didn’t care.

As with a lot of UK cold cases that I follow this one feels so solvable. But I get the feeling that, if we do find out who did it and why, we’ll still be scratching our heads about certain aspects of the crime.

 

[SHADOWW7]

Thanks so much for clarifying this — I genuinely didn’t know the police had already confirmed the detail about the killer taking some of Mikio’s clothes. Really appreciate you pointing that out.

That definitely helps me refine my thinking. And yes, I agree about the cash — at this point it’s just one of those things where multiple explanations are possible, and without hard evidence it stays in the “open speculation” category.

Thanks again for the info. It really helps to hear from people who’ve followed the case longer than I have.

 

[SHADOWW7]

The fact the killer's clothes were covered in blood and that he took some clothes from within the house has been already confirmed by the police and it is also a known fact: the killer took some of Mikio's clothes (a sweater or possibly something else I'm forgetting right now) and the police never found them again.

Nothing has ever been linked to this and the police never commented again so it must mean there was no follow up on it.

As per the money being taken is anyone's guess really, it could be argued it was for this and that but ultimately there is no definitive proof about any angle.

What do you think actually happened in this case? I’m studying it right now and I want to understand different perspectives. You seem experienced, so your theory or logical explanation would really help me

 

[Eliver]

What do you think actually happened in this case? I’m studying it right now and I want to understand different perspectives. You seem experienced, so your theory or logical explanation would really help me

Apologies if this comes out as rude (I'm saying it with the most neutral tone possible, I swear), but I have a lot of opinions and theories about this case that I will not be discussing openly in this thread.

However, if you are interested in my stance, what I can tell you is that by reading the past threads (especially around the end of thread 3 when I registered to websleuths, up until this one) you might have a general idea of what I think/what are my opinions about many aspects.

The Setagaya murder is riddled with misinformation and incorrect things that the general audience report as facts and so this is yet another reason why there are many things I prefer not to discuss openly.

 

[SHADOWW7]

Apologies if this comes out as rude (I'm saying it with the most neutral tone possible, I swear), but I have a lot of opinions and theories about this case that I will not be discussing openly in this thread.

However, if you are interested in my stance, what I can tell you is that by reading the past threads (especially around the end of thread 3 when I registered to websleuths, up until this one) you might have a general idea of what I think/what are my opinions about many aspects.

The Setagaya murder is riddled with misinformation and incorrect things that the general audience report as facts and so this is yet another reason why there are many things I prefer not to discuss openly.

Thank you — and really, there’s no need to apologize at all. You didn’t sound rude in the slightest. In fact, you corrected a couple of my assumptions, and that’s exactly why I came to Websleuths: to learn from people who have followed this case for years and can point out where I’m misunderstanding things.

I’m still very new to studying real cases, so I never assume my theory is “right.” I’m just trying to connect small details and explore angles that maybe haven’t been discussed as much. It honestly frustrates me how this case has stayed unsolved for over two decades despite the amount of evidence, so maybe I posted my thoughts too quickly out of that frustration.

I also fully understand why you don’t want to share your theories openly in the thread — with all the misinformation around this case, it makes sense to be careful. I’ll definitely go through the previous threads like you recommended so I can get a better understanding of your perspective and the overall timeline of discussions here.

Thanks again for taking the time to guide a newcomer. It genuinely helps me think more clearly and avoid repeating common mistakes.

 

[Charlot123]

Was a big fan of this podcast but never thought to look the case up on here, is this still in the works? Hopefully it’s progressing well, it’d be great to get more quality content on this case.

Very difficult crime to make sense of. My hunch is the perpetrator was very young and/or very mentally unwell. I think even in 2000 a killer being so careless as to leave a lot of DNA at a crime scene was understandable, particularly in a country with very restrictive DNA laws, but to leave fingerprints all over the place? Your common or garden criminal would surely be too clued up to be that lax - unless, I suppose, they thought there was no chance their prints could ever be matched, such as if they were leaving the country? Though if the perp had a military connection they’d no doubt have been fingerprinted at some point, which you’d think would make them a little more forensically aware? But maybe they just didn’t care.

As with a lot of UK cold cases that I follow this one feels so solvable. But I get the feeling that, if we do find out who did it and why, we’ll still be scratching our heads about certain aspects of the crime.

I think that he was rather young. Maybe not 13 or 15, but not 30, either. Around 19-20.

The more I think, the more I feel that he was in somewhat dissociative state after the murders. It may happen after a huge outpouring of mental energy. So his actions were more random than logical and maybe hard to understand. When I try to imagine how he came across, I tend to agree with you that he probably had some mental/neurological condition, and appears slightly detached, but his behavior is not outlandish. Perhaps he is not in touch with his emotions. He’d probably answer “I don’t know” to the question, “why did you kill them”? At the same time, he looks placid and not intimidating, so the Miyazawas could even open the door to him. (I might be wrong here - after all, “comfort food” in his stomach might indicate being somewhat agitated when he left the house, and mom trying to calm him down).

With all of this, he may still be in Japan and fly under the radar for an obvious reason. He may looks slightly off but he behaves quietly. In Japan, staring at someone is rude, unless one starts acting out, but he doesn’t.

Sometimes I think, is he even alive?

 

[Bobban]

coagulated blood i assume can still smear and stain. Found this video on YouTube that shows a time laps of different size blood pools drying:

Not sure what the size is of the last pool but it doesn't dry up until 10+h.

TMI- but I had a really bad nosebleed once out of nowhere where I had to catch the blood in my palm before I could reach a bathroom. By the time I reached a bathroom it had already coagulated into a 4x4cm clot that when touched would break from its jelly like form and return into a liquid.

I think if there was any bigger pools of blood in the house it could very well still be jelly like and wet. Bigger spots that are dry on the surface could still be wet within if stepped on. (I have no medical expertise, please correct me if I'm wrong!)

 

[Lalalacasbah]

I’m not an expert at all — I only recently started studying cold cases and I’m still learning how to connect puzzle pieces properly. But after going through the Setagaya case details again, one small theory made some sense to me, so I’m sharing it humbly in case it adds anything.

If the newer DNA interpretation is correct and the killer was actually in his 30s, it fits a certain pattern: not a reckless teenager, but also not a trained professional — someone capable of basic planning but still careless in major ways.

One thought is that his clothes may have gotten completely soaked in blood during the attack. That would explain why he left behind items like the jacket, hat, scarf, and gloves. But he obviously couldn’t walk out without clothes, so maybe he grabbed something from the Miyazawa family wardrobe just to escape the house.

Ill-fitting or unfamiliar clothing could attract attention, though. That might be why he took the small amount of cash — not as theft, but to buy cheap clothes quickly or pay for transport, then dump whatever Miyazawa clothing he had on.

It doesn’t address every part of the case (like the sand, bathroom behaviour, ice cream, etc.), but as a single thread, this idea seemed somewhat practical to me.
Just sharing it as my personal theory — please don’t copy or repost without credit.

And if anyone here feels this line of thinking makes sense (or notices weak points or missing angles), please feel free to add on or point it out. I’m still learning, and any corrections or additions would actually help improve the theory.


Just sharing it as my personal theory — please don’t copy/repost without credit.

Welcome to Websleuths @SHADOWW7!

Please keep sharing ideas and posting. We all like to brainstorm, theorize and hypothesize. I think good to be open minded about all scenarios on cases to not always have too much tunnel vision.

 

[Sillybilly]

Just spitballing some ideas here ...

Could be nothing, and I know Setagaya, Tokyo and Nagoya are a couple of hours apart, but in the Takaba murder, the 2 y.o. boy Kohei was left unharmed. In this Miyazawa case, 6 y.o. Rei's killing was different from the rest of his family in that he was not stabbed (so, please excuse me for referring to it as a 'softer' killing). Just hit me that in both cases, the young males were treated differently from the other victims.

Also, at the time of the murder of Namiko Takaba on November 13, 1999, her husband Satoru Takaba (now 69 y.o.) would have been 43 years old at the time. In the Miyazawa murders a year later in December 2000, Mikio was 44 years old so would have been the same age as Satoru.

Based on the ages of both adult males in the two families, just wondering if there's any chance that Nikio had also crossed paths with an insanely jealous Kumiko Yasufuku in the past (sports, schooling, convenience store/supermarket or other employment ??)

In both cases, a break and enter, and an unusual 'food' element in both crimes ... in the Takaba murder, a carton of Yakult noodle cup that Satoru says did not belong in the home was left behind, and we know of the food related elements in this case of the Miyazawa family.

 

[Eliver]

Just spitballing some ideas here ...

Could be nothing, and I know Setagaya, Tokyo and Nagoya are a couple of hours apart, but in the Takaba murder, the 2 y.o. boy Kohei was left unharmed. In this Miyazawa case, 6 y.o. Rei's killing was different from the rest of his family in that he was not stabbed (so, please excuse me for referring to it as a 'softer' killing). Just hit me that in both cases, the young males were treated differently from the other victims.

Also, at the time of the murder of Namiko Takaba in November 1999, her husband Satoru Takaba (now 69 y.o.) would have been 43 years old at the time. In the Miyazawa murders a year later in December 2000, Nikio was 44 years old so would have been the same age as Satoru.

Based on the ages of both adult males in the two families, just wondering if there's any chance that Nikio had also crossed paths with an insanely jealous Yasufuku in the past (sports, schooling, convenience store or other employment ??)

In both cases, a break and enter, and an unusual 'food' element in both crimes ... in the Takaba murder, a juice or drink box (iirc) that Satoru says did not belong in the home was left behind, and we know of the food related elements in this case of the Miyazawa family.

<modsnip: Quoted post was edited to correct Rei's age>

While it is true that both Kohei and Rei had a different treatment (so to say...), the circumstances seem very different: being the first killed, Rei was strangled seemingly to preserve the element of surprise (the killer's alleged entry point was just next to his bedroom) while the others were killed with the knife, starting from the second victim Mikio: an adult male (aka the biggest threat in the house), while the two women were not "finished" by the killer right away thus also explaining a rising escalation in violence IMHO (get down the ladder with the adrenaline pumping, go to the kitchen, take another knife, go back and see them still alive at the bottom of the ladder, etc.)

Kohei, on the other hand, was left untouched but we could also speculate Yasufuku Kumiko wanted to kill him as well but couldn't bring herself to do it after killing Namiko (because she was wounded? Because she also has a child? We don't know).

About Mikio meeting an insanely jealous person.
Although the police also made it clear the Miyazawa's past was looked into thoroughly and nothing out of the ordinary came out, one could argue that the Nagoya case also didn't have anything out of place so it's anyone's guess if the TMPD really ruled out everyone.

There is also the certainty the killer of the Miyazawa was a male and was also young (not older than 30 years old according to the yet to be confirmed reports of this summer) so it appears very difficult to be related to jealousy: if he was 15 as per the initial report there is simply no way to explain the age gap, while if he really was 30 it's still a stretch but no so hard I suppose?

Before the unconfirmed reports of this summer, the killer's age window was reported as 15-24 years old.

On the other hand, absolutely possible that a younger/more immature person might harbor feelings that could lead to a disproportionate reaction such as this.