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

[Frankie Hellis]

“Highlighter ink, car coolant and anti-freeze often have very similair ingredients…”

Well darn, I will never lick my dried out highlighter again.

 

[Bobban]

I'm recalling my own theory regarding the perpetrator being someone who works with vehicles (lol). It makes no sense that (as far as the TMPD has said) there was no oil or other car liquid found in the bag. If by my theory; the rhodamine got into the bag through tools that were used on a car, there would 100% be a lot of dirty oil and other substances all over and in that bag.

The A/C repair angle should still be plausible since it's a more sanitary job. But it's a theory waiting to be popped by additional information and knowledge.

 

[Hoodwinked]

I don't think the rhodamine being found in his bag and the Miyazawa's garage tells us that he has been in their garage. I think it very much makes sense that car coolant and/or antifreeze was being stored in the garage probably by Mikio. Garages are one of few places you can almost expect to find rhodamine since changing car coolant or anti-freeze in the car is something people can do at home by themselves.

Highlighter ink, car coolant and anti-freeze often have very similair ingredients. They swith around the percentages and have different additives but its all glycol, water, dye (rhodamine for pink/red).

I see. Well, much appreciated for clearing it up for me. Honestly I didn't know about the Highlighter ink, car coolant & anti-freeze often having similar ingredients. You really do learn something new everyday huh?

 

[Hoodwinked]

The ‘24 documentary covers this, and there are even images of officers with no gloves on leaning against the stairwell wall that has blood on it writing on a notepad.

It really makes you think about how competent the TMPD (Japanese police in general) were around that time since quite a few unsolved violent crimes happened within a couple years before or after the Miyazawa family murders. The few unsolved (some solved recently) cases that I recall to mind are the Namiko Takaba case, Hachioji Nanpei Owada triple murders & the Junko Kobayashi murder etc.

 

[Hoodwinked]

Perhaps it's a bit redundant of me bring up a topic that might've been covered in previous threads or indeed this thread but I'll do it anyway. How sure are we about how long the perpetrator stayed in the house after murdering the family? I'm aware that the only certain timestamps we have to rely on are the 1:18am to 1:23am the 5mins he spent messing around on the computer on the first floor. However, there's really no certainty on how long after these timestamps he was in the house or indeed what time he fled from the Miyazawa property.

Of course, anyone remotely familiar with this case will point out the theory that the perp might've have left as late as 10am in the morning based on the police report that the computer came back on around that time. However, as we all know Obregon has said that the TMPD mentioned that it was likely the Grandmother Haruko who might've moved the mouse on the desk, after fainting (or collapsing) from shock upon seeing Mikio's body.

I'm a lil skeptical about this though because how does it match chronologically from the time the computer turns back on and the time when Haruko found the bodies? Perhaps @Incoherent can help me out here because I've heard that An Irie in her book or somewhere else mentioned that Haruko came in to the Miyazawa house between 10:30-10:40am but the computer was reported to have turned back on before that.

 

[Eliver]

Perhaps it's a bit redundant of me bring up a topic that might've been covered in previous threads or indeed this thread but I'll do it anyway. How sure are we about how long the perpetrator stayed in the house after murdering the family? I'm aware that the only certain timestamps we have to rely on are the 1:18am to 1:23am the 5mins he spent messing around on the computer on the first floor. However, there's really no certainty on how long after these timestamps he was in the house or indeed what time he fled from the Miyazawa property.

Of course, anyone remotely familiar with this case will point out the theory that the perp might've have left as late as 10am in the morning based on the police report that the computer came back on around that time. However, as we all know Obregon has said that the TMPD mentioned that it was likely the Grandmother Haruko who might've moved the mouse on the desk, after fainting (or collapsing) from shock upon seeing Mikio's body.

I'm a lil skeptical about this though because how does it match chronologically from the time the computer turns back on and the time when Haruko found the bodies? Perhaps @Incoherent can help me out here because I've heard that An Irie in her book or somewhere else mentioned that Haruko came in to the Miyazawa house between 10:30-10:40am but the computer was reported to have turned back on before that.

There is no exact time when the PC went back on around 10.
As far as I know the PC turning back on and Haruko entering the house is around the same time and the police has never followed up on this. I'm guessing because it was not important/relevant after all and it was her indeed that turned it back on (also no information about any activity on the PC but simply that "went back on", meaning most probably it was the mouse that was touched/moved accidentally and prompted the PC to go from idle to active).

As previously discussed in the threads, we have no exact time of when the perpetrator left and ultimately it's all a matter of speculation. It could have been shortly after 1:18 - 1:23 (as you said, the only certain time we know he was there because of the PC activity) or hours later.

My personal opinion is that he left sometime during the night (let's say 2:00 - 3:00 as a general time) but not at 10 in the morning. It wouldn't make sense that he left at that time since more people might have seen him.

 

[Incoherent]

Perhaps it's a bit redundant of me bring up a topic that might've been covered in previous threads or indeed this thread but I'll do it anyway. How sure are we about how long the perpetrator stayed in the house after murdering the family? I'm aware that the only certain timestamps we have to rely on are the 1:18am to 1:23am the 5mins he spent messing around on the computer on the first floor. However, there's really no certainty on how long after these timestamps he was in the house or indeed what time he fled from the Miyazawa property.

Of course, anyone remotely familiar with this case will point out the theory that the perp might've have left as late as 10am in the morning based on the police report that the computer came back on around that time. However, as we all know Obregon has said that the TMPD mentioned that it was likely the Grandmother Haruko who might've moved the mouse on the desk, after fainting (or collapsing) from shock upon seeing Mikio's body.

I'm a lil skeptical about this though because how does it match chronologically from the time the computer turns back on and the time when Haruko found the bodies? Perhaps @Incoherent can help me out here because I've heard that An Irie in her book or somewhere else mentioned that Haruko came in to the Miyazawa house between 10:30-10:40am but the computer was reported to have turned back on before that.

An says in her book the time had passed 10:30am by the time Haruko went over to the house, and that she was there for around 5 minutes but not more than 10. The computer access that morning has only been reported as “around 10am” with no definitive time mentioned, unlike the earlier access at 1:18am. This is because the mouse was manipulated during the earlier time and things were clicked on and opened for the duration of use, but in the morning the mouse was not used so it was determined that the mouse falling was the cause of the computer waking up as it was also found hanging down from the desk. The TMPD conducted experiments with the same computer to see if this could be the case and the results were that it was. Haruko, An, and her husband had all been in the house that morning.

Re: his escape time, no one knows. But I want to thank you for your comment because it made me look back at a few pages in her book and found a small missed detail.
An and her son had gone to bed at 11pm that night. An and her husband on the second floor, Haruko on the second floor, the son on the 3rd floor. Her husband was falling asleep around 9pm already due to jet lag from returning to Japan the week prior.
Haruko was watching TV in her room and had a habit falling asleep with it left on. So much so that An and her husband had a habit of wearing earplugs to sleep. An says that night she did wear earplugs, but that they were not very tight. She says she was still able to hear the wind blowing occasionally and was strangely not able to fall asleep until after 1am, even though she was very tired.

So, to go back to his escape time, An confirms she was still awake around the time he was using the computer. If he escaped shortly after I wonder if she would have been able to hear it with her earplugs in? She mentions she could hear the wind after all.
To me it seems likely he left a while after but not after sunrise due to the risk of being seen by early risers in the neighbourhood. Perhaps the 2-3am mark? JMO.

This makes me realise I should read through her book again more carefully in case there are any more missed details.

 

[Lalalacasbah]

It really makes you think about how competent the TMPD (Japanese police in general) were around that time since quite a few unsolved violent crimes happened within a couple years before or after the Miyazawa family murders. The few unsolved (some solved recently) cases that I recall to mind are the Namiko Takaba case, Hachioji Nanpei Owada triple murders & the Junko Kobayashi murder etc.

I haven't heard of the Junko Kobayashi murder before. There's a thread here on WS for it but it's not active, very little posts:

D

Thread 'Japan- Junko Kobayashi, 21, English major @ Sophia Uni, fatally stabbed in neck, bound before & after death, home set on fire, 9/9/96, *Reward/DNA*'

Apr 5, 2024

Sep. 15, 2023 rbbm

Reward period extended for information that will help solve 27-year-old murder case

The National Police Agency has extended the reward period by one year for information that will help solve the 1996 murder of a 21-year-old woman. Junko Kobayashi, a Sophia University student, was bound and stabbed to death inside her house which was then torched, in Katsushika Ward on Sept 9,…

japantoday.com

''Junko Kobayashi, a Sophia University student, was bound and stabbed to death inside her house which was then torched, in Katsushika Ward on Sept 9, 1996. Police have questioned more than 75,000 people and followed up on over 1,100 leads but have yet to come close to identifying a suspect or suspects.
The murder is believed to have taken place at around 3.55 p.m. Around this time, a man in an ocher-colored raincoat was seen standing outside...

• dotr
• Replies: 3
• Forum: Cold Cases

• 
• 
• 

I'm assuming no one here thinks any connection of Junko and the Miyazawas? I know they're 4 years apart and looks like locations are about 43 minutes apart according to Google. Both likely both have train stations and strange knife choice for both crimes but likely not too many similarities.

Unless a killer escalated but Junko's sounds like it's possibly personal with the timing of her leaving in 2 days. Very sad to hear these unsolved crimes!

 

[Incoherent]

I haven't heard of the Junko Kobayashi murder before. There's a thread here on WS for it but it's not active, very little posts:

D

Thread 'Japan- Junko Kobayashi, 21, English major @ Sophia Uni, fatally stabbed in neck, bound before & after death, home set on fire, 9/9/96, *Reward/DNA*'

Apr 5, 2024

Sep. 15, 2023 rbbm

Reward period extended for information that will help solve 27-year-old murder case

The National Police Agency has extended the reward period by one year for information that will help solve the 1996 murder of a 21-year-old woman. Junko Kobayashi, a Sophia University student, was bound and stabbed to death inside her house which was then torched, in Katsushika Ward on Sept 9,…

japantoday.com

''Junko Kobayashi, a Sophia University student, was bound and stabbed to death inside her house which was then torched, in Katsushika Ward on Sept 9, 1996. Police have questioned more than 75,000 people and followed up on over 1,100 leads but have yet to come close to identifying a suspect or suspects.
The murder is believed to have taken place at around 3.55 p.m. Around this time, a man in an ocher-colored raincoat was seen standing outside...

• dotr
• Replies: 3
• Forum: Cold Cases

• 
• 
• 

I'm assuming no one here thinks any connection of Junko and the Miyazawas? I know they're 4 years apart and looks like locations are about 43 minutes apart according to Google. Both likely both have train stations and strange knife choice for both crimes but likely not too many similarities.

Unless a killer escalated but Junko's sounds like it's possibly personal with the timing of her leaving in 2 days. Very sad to hear these unsolved crimes!

From what I remember of this case the culprit was a middle aged man in a yellow raincoat holding an umbrella and was standing across the street from the house, and then also directly in front of the door. He was seen by several people in both locations as well as running away.

The train station is Shibamata and the location of the house was close enough to be made in a few minutes at a fast pace or run. It also happened in the middle of the afternoon!

Very sad case but unrelated. You’ll go down a rabbit hole reading about that one though for sure.

 

[AircraftAmateur]

Hello, I’m a new member here. I got interested in this case since I currently work as a civilian aircraft mechanic at Edwards Air Force Base. I won’t be divulging too many personal details for obvious reasons but I am interested in the contents of the hip bag.

I’m seeing a lot of discussion about the crime scene evidence and people are investigating the most likely sources: auto repair workers, household focused tradesmen, hobbyists, etc.

But I suspect the killer or perhaps the killer’s parent(s) was/were affiliated not just with the United States military but more specifically with aircraft maintenance. Many aircraft maintenance career fields have used or use powdered dyes and can have this residue along with glass beads on their personal items inadvertently. In some cases it can be as common as finding old screws or lightbulbs on one’s personal items after work.

One career field for example has publicly available tech data about their process that references these materials. The career field is NDI, aka: Nondestructive Inspections. These technicians would be present in both the US Air Force and the US Naval Air Forces. As for source of the tech data I have attached the PDF file. You can also find this PDF if you search for “NONDESTRUCTIVE INSPECTION METHODS, BASIC THEORY” into Google. It’ll be a .mil address from Tinker Air Force Base.

The two paragraphs of this tech data appear to line up quite well with the powdered dyes and the glass particles found in in the hip bag:


“2.1.2.1 The oil-and-whiting method was replaced by magnetic particle inspection on steel and ferrous parts in 1930.

However, industries using non-ferromagnetic metals, especially aircraft manufacturers, needed a more reliable and sophisticated tool than discolored machine oil and chalk. In 1941, fluorescent dye materials were added to highly penetrating oil to make a penetrant material. Colored dyes, primarily red, were introduced a little later. Since then, a large number of penetrant systems or families have evolved. These include developments in various types and concentrations of dye materials, types of penetrating oils and additives, materials and methods for removing the excess surface penetrant, and various materials and forms of developing agents.”

And,

“2.10.1.2.1 Abrasive Blast. Abrasive blast media used to remove paint coatings include, but are not limited to, materials such as plastic media, glass bead, dry ice, and alumina grit. Plastic Media Blast (PMB) is often the preferred process for paint removal on aluminum and magnesium components due, largely, to its relatively minimal peening effect on the part surface.

However, even though PMB has less effect on the surface than most other materials, it has been shown to cause enough surface deformation of aluminum and magnesium to cause crack closure and prevent fluorescent penetrant entry. In addition to closing cracks by the peening effect of the particles hitting the surface, abrasive blast may also clog cracks with residues of the abrasive media preventing effective penetrant inspection. Glass bead and alumina grit blast are considerably more aggressive processes and should only be used when specific engineering directive authorizes their use.”

 

[Lalalacasbah]

Hello, I’m a new member here. I got interested in this case since I currently work as a civilian aircraft mechanic at Edwards Air Force Base. I won’t be divulging too many personal details for obvious reasons but I am interested in the contents of the hip bag.

I’m seeing a lot of discussion about the crime scene evidence and people are investigating the most likely sources: auto repair workers, household focused tradesmen, hobbyists, etc.

But I suspect the killer or perhaps the killer’s parent(s) was/were affiliated not just with the United States military but more specifically with aircraft maintenance. Many aircraft maintenance career fields have used or use powdered dyes and can have this residue along with glass beads on their personal items inadvertently. In some cases it can be as common as finding old screws or lightbulbs on one’s personal items after work.

One career field for example has publicly available tech data about their process that references these materials. The career field is NDI, aka: Nondestructive Inspections. These technicians would be present in both the US Air Force and the US Naval Air Forces. As for source of the tech data I have attached the PDF file. You can also find this PDF if you search for “NONDESTRUCTIVE INSPECTION METHODS, BASIC THEORY” into Google. It’ll be a .mil address from Tinker Air Force Base.

The two paragraphs of this tech data appear to line up quite well with the powdered dyes and the glass particles found in in the hip bag:


“2.1.2.1 The oil-and-whiting method was replaced by magnetic particle inspection on steel and ferrous parts in 1930.

However, industries using non-ferromagnetic metals, especially aircraft manufacturers, needed a more reliable and sophisticated tool than discolored machine oil and chalk. In 1941, fluorescent dye materials were added to highly penetrating oil to make a penetrant material. Colored dyes, primarily red, were introduced a little later. Since then, a large number of penetrant systems or families have evolved. These include developments in various types and concentrations of dye materials, types of penetrating oils and additives, materials and methods for removing the excess surface penetrant, and various materials and forms of developing agents.”

And,

“2.10.1.2.1 Abrasive Blast. Abrasive blast media used to remove paint coatings include, but are not limited to, materials such as plastic media, glass bead, dry ice, and alumina grit. Plastic Media Blast (PMB) is often the preferred process for paint removal on aluminum and magnesium components due, largely, to its relatively minimal peening effect on the part surface.

However, even though PMB has less effect on the surface than most other materials, it has been shown to cause enough surface deformation of aluminum and magnesium to cause crack closure and prevent fluorescent penetrant entry. In addition to closing cracks by the peening effect of the particles hitting the surface, abrasive blast may also clog cracks with residues of the abrasive media preventing effective penetrant inspection. Glass bead and alumina grit blast are considerably more aggressive processes and should only be used when specific engineering directive authorizes their use.”

Welcome to Websleuths!! Great post!!

This is info is really good. Others who know the case better will likely have more input and more details but if I recall Mikio was an aviation enthusiast... very interesting connection.

Looking forward to more posts!

 

[Incoherent]

An article about CCTV cameras and a man running by that was published December 28th, that I missed as it requires a subscription to read all of it.

It was reported that at 10:53am, 3 minutes before the police arrived at the house on December 31st 2000, a security camera outside a 711 about 100m from the house showed a man running by and heading in the direction of Sengawa train station.
He is described as being around 180cm tall, wearing a blue coat and black trousers. He has never been found nor captured on any other camera. It does not mean he was implicated, but has been described as “suspicious”.

Around the area of the scene there were 15 convenience stores, 1 pachinko parlour, and 1 post office at the time.
It was reported police seized footage from 18 security cameras around the area after the crime but that none of them showed anything.

It goes on to say that of the 4 train stations around the house within a 30 minute walk (Sengawa, Chitose Karasuyama, Seijogakuen Mae, Soshigaya Okura) none of them had security cameras at the time. They were not introduced until April 2001 on Keio lines and 2003 on Odakyu lines.

Unfortunately I cannot finish the article as it requires a paid subscription.

Mainichi article

 

[dotr]

An article about CCTV cameras and a man running by that was published December 28th, that I missed as it requires a subscription to read all of it.

It was reported that at 10:53am, 3 minutes before the police arrived at the house on December 31st 2000, a security camera outside a 711 about 100m from the house showed a man running by and heading in the direction of Sengawa train station.
He is described as being around 180cm tall, wearing a blue coat and black trousers. He has never been found nor captured on any other camera. It does not mean he was implicated, but has been described as “suspicious”.

Around the area of the scene there were 15 convenience stores, 1 pachinko parlour, and 1 post office at the time.
It was reported police seized footage from 18 security cameras around the area after the crime but that none of them showed anything.

It goes on to say that of the 4 train stations around the house within a 30 minute walk (Sengawa, Chitose Karasuyama, Seijogakuen Mae, Soshigaya Okura) none of them had security cameras at the time. They were not introduced until April 2001 on Keio lines and 2003 on Odakyu lines.

Unfortunately I cannot finish the article as it requires a paid subscription.

Mainichi article

Maybe the perp worked at one of the train stations? speculation.

 

[Incoherent]

Maybe the perp worked at one of the train stations? speculation.

The article says only Shinjuku station had cameras at the time. It certainly means he could’ve used trains if he was able to not look suspicious. The hand injury may have been a problem, but I am admittedly surprised that there were supposedly absolutely no cameras at all.