Setagaya Family Murder

[Harry D]

Have any fellow crime buffs read about this case?

On 30 December 2000 in Setagaya, Japan, an unidentified intruder broke into the Miyazawa family home and murdered the husband, wife and their two young children.

There was seemingly no motive to the murders. The intruder stole some money but he left behind more than was taken. The case is often remembered for the fact the killer remained behind at the house for several hours after the murders. He raided their food, browsed on the family computer, left a dump in the toilet, and there's even evidence that he took a nap on the sofa. The killer also made little attempt to cover his tracks. Police found his fingerprints everywhere and traces of his blood from where one of the victims fought back before they died. The killer also left behind the knife, a fanny pack, shoes, scarf and other items.

Police analysed sand samples found inside the killer's bag and traced it to the Nevada desert, specifically the Edwards Air Force Base in California. Analysis of the killer's DNA determined that he is of mixed East Asian and European descent, although his European heritage could be a distant ancestor rather than a parent.

Despite having the killer's DNA and vast amounts of information, the Miyazawa's murderer remains at large.

[Herlock Sholmes]

Have any fellow crime buffs read about this case?

On 30 December 2000 in Setagaya, Japan, an unidentified intruder broke into the Miyazawa family home and murdered the husband, wife and their two young children.

There was seemingly no motive to the murders. The intruder stole some money but he left behind more than was taken. The case is often remembered for the fact the killer remained behind at the house for several hours after the murders. He raided their food, browsed on the family computer, left a dump in the toilet, and there's even evidence that he took a nap on the sofa. The killer also made little attempt to cover his tracks. Police found his fingerprints everywhere and traces of his blood from where one of the victims fought back before they died. The killer also left behind the knife, a fanny pack, shoes, scarf and other items.

Police analysed sand samples found inside the killer's bag and traced it to the Nevada desert, specifically the Edwards Air Force Base in California. Analysis of the killer's DNA determined that he is of mixed East Asian and European descent, although his European heritage could be a distant ancestor rather than a parent.

Despite having the killer's DNA and vast amounts of information, the Miyazawa's murderer remains at large.

That’s a strange case Harry. I just checked it out on Wikipedia. I can only think that the culprit was so unbalanced (taking no precautions and leaving stuff behind) that he’s bound to come to the attention of the law sooner or later in some way? Will it cost more lives though?

[Abby Normal]

harry do you know if they entered is fingerprints or dna in US codis database? also was there any evidence of sexual assault?
sounds to me like he was an american serviceman. and that perhaps since his paternal dna indicated east asian decent, on his father side may be japanese, which might be the link to him being in japan. or maybe even link to that particular family.

[Harry D]

That’s a strange case Harry. I just checked it out on Wikipedia. I can only think that the culprit was so unbalanced (taking no precautions and leaving stuff behind) that he’s bound to come to the attention of the law sooner or later in some way? Will it cost more lives though?

You'd like to think so, Herlock. I can't imagine this was his first rodeo or his last. But it has been over two decades since the murders and they don't appear any closer to apprehending him, despite all that evidence.

harry do you know if they entered is fingerprints or dna in US codis database? also was there any evidence of sexual assault?
sounds to me like he was an american serviceman. and that perhaps since his paternal dna indicated east asian decent, on his father side may be japanese, which might be the link to him being in japan. or maybe even link to that particular family.

Not exactly sure, Abby. I know his DNA was run through a criminal database and came up blank, but I'm not aware if Japan uses CODIS? I've read that the Japanese police are not the most progressive when it comes to international cooperation or forensic technology.

Also, due to their low crime rate, there's a cultural bias that a native could not commit such terrible crimes. Not too dissimilar to the mindset back in 1888. Apparently, they have a history of fabricating evidence to frame foreigners. I'm not saying that applies to this particular investigation, but it has given me pause. I was amazed they were able to narrow sand samples down to a specific naval base?

As far as I know, there were no signs of sexual assault. The husband, wife and daughter were all stabbed to death. The son was strangled.

[Herlock Sholmes]

Harry, I was a bit remiss in not paying enough attention to the year. The guy could be under lock and key or under the ground of course. If we’re all still ok I can see you ‘refreshing’ this thread in 10 years time. A strange and sad case.

[Abby Normal]

You'd like to think so, Herlock. I can't imagine this was his first rodeo or his last. But it has been over two decades since the murders and they don't appear any closer to apprehending him, despite all that evidence.



Not exactly sure, Abby. I know his DNA was run through a criminal database and came up blank, but I'm not aware if Japan uses CODIS? I've read that the Japanese police are not the most progressive when it comes to international cooperation or forensic technology.

Also, due to their low crime rate, there's a cultural bias that a native could not commit such terrible crimes. Not too dissimilar to the mindset back in 1888. Apparently, they have a history of fabricating evidence to frame foreigners. I'm not saying that applies to this particular investigation, but it has given me pause. I was amazed they were able to narrow sand samples down to a specific naval base?

As far as I know, there were no signs of sexual assault. The husband, wife and daughter were all stabbed to death. The son was strangled.

thanks harry. this is a revenge/jealousy killing by mixed japanese american military or ex military man who knew the family he murdered.

[Harry D]

Harry, I was a bit remiss in not paying enough attention to the year. The guy could be under lock and key or under the ground of course. If we’re all still ok I can see you ‘refreshing’ this thread in 10 years time. A strange and sad case.

I was wondering if they could use a genealogy database to narrow him down, the kind that was used to catch the Golden State Killer, but again I don't know if the Japanese are up to date on these methods.

thanks harry. this is a revenge/jealousy killing by mixed japanese american military or ex military man who knew the family he murdered.

I'm curious Abby, why you think he knew the family? I've read plenty of grisly home invasions with no prior relationship between victim(s) and invader(s).

[Abby Normal]

I was wondering if they could use a genealogy database to narrow him down, the kind that was used to catch the Golden State Killer, but again I don't know if the Japanese are up to date on these methods.



I'm curious Abby, why you think he knew the family? I've read plenty of grisly home invasions with no prior relationship between victim(s) and invader(s).

because unknown intruders are usually after something more than murdering the whole family. Like obvious robbery or sexual assault like the GSK or BTK. without these usual stranger motives present, more than likely its like the case of a recent murder of a family in CA (i forgot the name) the whole family was killed-no apparent motive, and it turned out to be someone known to the husband who was a former friend/business partner who was pissed off and jealous of him.

also, since this was an apparent one off, as in no other similar crimes occuring before or after--it points away from a serial killer, or person/s who started a home invasion robbery crime spree-and points to a known to family killer. traditional motive for murder thats as old as cane and abel-anger, pride , jealosy. the example in CA was also a one off.