Coordinates: 35°39′22.8″N 139°35′55.4″E
Setagaya family murder
The Setagaya family murder (Japanese: 世田谷一家殺害
事件, Hepburn: Setagaya ikka satsugai jiken) refers to the
unsolved murders of the Miyazawa family in Setagaya ward
of Tokyo, Japan, on 30 December 2000.[1]
Mikio Miyazawa, Yasuko Miyazawa, Niina Miyazawa and
Rei Miyazawa were murdered during a home invasion at
night by an unknown assailant who then remained in the
Miyazawas' house for several hours before disappearing.
Japanese police launched a massive investigation that
uncovered the killer's DNA and many specific clues about
their identity, but the perpetrator has never been identified.
The media frenzy and long investigation of the Setagaya
murders became a cause célèbre to abolish statute of
limitations in Japan, which was removed in 2010.[2]
Setagaya family murder
The Miyazawa home in Setagaya in
2010. Neighboring houses at the
time of the murders have since been
demolished.
Location
Setagaya, Tokyo,
Japan
Contents
Coordinates 35°39′22.8″N
139°35′55.4″E
Murders
Date
December 30, 2000
Investigation
Suspect
Target
Miyazawa family (4
Legacy
See also
References
External links
Murders
people)
Attack type
Mass murder, home
invasion
Weapons
Knife
Deaths
4
3 due to knife
wounds
1 due to
strangulation
On 31 December 2000, the corpses of 44-year-old Mikio Victims
Mikio Miyazawa, 44
Miyazawa, his 41-year-old wife Yasuko, and their children,
Yasuko Miyazawa, 41
8-year-old Niina and 6-year-old Rei, were discovered by
Yasuko's mother, Haruko, at their house in the
Niina Miyazawa, 8
Kamisoshigaya neighborhood of Setagaya, in the western
Rei Miyazawa, 6
suburbs of Tokyo.[3] Mikio, Yasuko, and Niina had been
stabbed to death while Rei had been strangled.[4] Perpetrator Unknown
Investigation of the crime scene by the Tokyo Metropolitan
Police Department (TMPD) concluded that the family had been murdered on December 30 at
around 11:30 p.m. (Japan Standard Time), after which
the killer stayed in the house for several hours.[5]
Takeshi Tsuchida, the chief of Seijo Police Station, was
designated as the person in charge of the investigation
at the time until his retirement.[6]
The killer entered through the open window of the
second floor bathroom at the rear of the house, located
immediately adjacent to Soshigaya Park, and gained
access by climbing up a tree and then removing the
window screen. The killer used his bare hands to
The rear of the Miyazawa house from
strangle Rei, sleeping in his room on the second floor,
Soshigaya Park in 2010.
killing him through asphyxiation. Mikio rushed up the
first floor stairs after he detected the disturbance in
Rei's room, fighting and injuring the killer until being stabbed in the head with a sashimi bōchō
knife. A police report claimed that part of the sashimi knife's blade broke off inside Mikio's
head, and the killer then attacked Yasuko and Niina with the broken knife until using a Santoku
knife from the house to murder them.
The killer remained inside the house for 2 to 10 hours, using the family computer, consuming 4
bottles of barley tea, melon, and 4 ice creams from their refrigerator, using their toilet and
leaving his feces in it without flushing, treating his injuries using first aid kits and other sanitary
products, and taking a nap on a sofa in the second floor living room. Drawers and papers were
ransacked (with some being dumped in the bath and toilet) and some money was taken
(although more was left behind). Surprisingly, the killer left 10 items behind too on the family
sofa (knife, muffler, hip bag, sweater, jacket, hat, gloves, shoes, and two handkerchiefs.).
An analysis of Mikio Miyazawa's computer revealed that it had connected to the internet the
morning after the murders at 1:18 a.m. and again at around 10 a.m., around the time Yasuko's
mother Haruko entered the house and discovered the murders. Haruko became suspicious after
being unable to call her daughter (the killer had unplugged the phone line) and visited the house
but received no answer after ringing the doorbell. Authorities believe the killer had stayed in the
house until at least 1:18 a.m. but the computer usage at 10 a.m. could have also been
accidentally triggered by Haruko accidentally moving the mouse during her discovery of the
crime scene.[5]
Investigation
Police have been able to deduce several very specific clues to the perpetrator's identity, but have
been unable to produce or apprehend a suspect. It was determined that the killer had eaten
string beans and sesame seeds the previous day after analyzing feces from the killer in the
Miyazawas' bathroom.[3] They determined that the clothes and sashimi knife left behind by the
killer had been purchased in Kanagawa Prefecture.
Police also learned that only 130 units of the killer's sweater were made and sold, but they have
only been able to track down twelve of the people who bought the sweaters.[4] Trace amounts of
sand were also found inside the hip bag that the perpetrator left at the scene, which after
analysis was determined to come from the Nevada desert, more exactly the area of Edwards Air
Force Base in California.[7]
Suspect
Investigators found the killer's DNA and fingerprints throughout the house, but none matched
their databases, indicating that they do not have a criminal record. Physically, the killer is
believed to be around 170 centimeters tall and of thin build.[8] The police estimate the killer was
born between 1965 and 1985 (15 to 35 years-old at the time of the incident) due to the
physicality required for entering the Miyazawa house and committing the murders. The
Miyazawas' wounds indicate that the killer is likely to be right-handed.
The killer's blood was gained during an analysis of the murder scene that revealed traces of Type
A blood, which would not have belonged to the Miyazawa family. A DNA analysis of the Type A
blood determined the killer is male and possibly mixed-race, with maternal DNA indicating a
mother of European descent, possibly from a South European country near the Mediterranean
or Adriatic Sea, and paternal DNA indicating a father of East Asian descent.[9]
It's considered possible that the European maternal DNA comes from a distant ancestor from
the mother's line rather than a fully European mother. Analysis of the Y-chromosome showed
the Haplogroup O-M122, a common haplogroup distributed in East Asian peoples, appearing in
1 in 4 or 5 Koreans, 1 in 10 Chinese, and 1 in 13 Japanese.[10] These results led to TMPD to seek
assistance through the International Criminal Police Organization as the killer may not be
Japanese or present in Japan.
Legacy
The investigation into the murders is among the largest in Japanese history, involving over
246,044 investigators who have collected over 12,545 pieces of evidence. All evidence related to
the case remains in custody.
In 2015, it was reported that forty officers were assigned to the case full-time. In 2019, it was
reported that thirty five officers are still assigned to the case. Every year, the TMPD makes a
pilgrimage to the house for memorial ceremonies. Takeshi Tsuchida, the chief of Seijo Police
Station, was designated as the person in charge of the investigation at the time until his
retirement.
In 2015, An Irie, older sister of Yasuko Miyazawa, filed a complaint to the Broadcast and
Human Rights and Other Related Rights Committee of the Broadcasting Ethics & Program
Improvement Organization after she claimed that the TV Asahi documentary aired in 2014
misrepresented her after a TV Asahi reporter and ex-FBI agent used profiling to back a theory
that the killer murdered the Miyazawas out of resentment.[11]
In 2019, the TMPD announced that the Miyazawa house will be torn down because of its
age/risk of collapsing with the interior already showing signs of deterioration.[12] The move was
appealed by the family and supporters. All evidence related to the case remains in
custody.[13][14]
See also
List of unsolved murders