Four victims · abundant forensics · no identified offender
The offender remained inside the Miyazawa home for hours and left blood, fingerprints, clothing, and personal items, yet decades of comparison have produced no public identification.
On the night of December 30-31, 2000, Mikio (44), Yasuko (41), Niina (8), and Rei (6) Miyazawa were killed inside their Kami-Soshigaya home in Setagaya, Tokyo. Investigators believe the intruder entered through a second-floor bathroom window beside Soshigaya Park, remained in the house for hours, used the family computer at about 1:18 a.m., and left behind blood, fingerprints, clothing, and other forensic evidence without being identified. Yasuko's mother discovered the bodies at about 10:40 a.m. on December 31; the case remains unsolved, with the Tokyo Metropolitan Police Department still publicizing a total reward of up to 20 million yen.
The Miyazawa home
The house beside Soshigaya Park
Recent developments
Recent reporting and official developments, labeled by source and verification status.
May 14, 2026 · FNN Prime Online
Tokyo police arrested two men suspected of entering the preserved Miyazawa family home and attempting to steal valuables, bringing renewed attention to the protected scene more than twenty-five years after the murders.
Context
Authorities have not connected the alleged break-in or the arrested men to the 2000 murders.
The scale
Key figures are drawn from the published case record.
The scene and its aftermath
The killings were followed by hours inside the house. Later investigation preserved a remarkable collection of biological traces, fingerprints, clothing, and objects.
See all 4 mapped locations →Dec 30, 2000
Between 11:30 p.m. and 12:05 a.m., an intruder killed the four family members inside their home.
Dec 31, 2000
The killer stayed inside, used the computer and bathroom, ate food, treated injuries, ransacked rooms, and left clothing and other items.
Dec 31, 2000
At 10:40 a.m., Haruko entered the home and found the four victims, prompting a major TMPD investigation.
Jan 1, 2013
TMPD used 3D printing to create a model of the house to support investigative reconstruction.
Dec 17, 2021
TMPD reported a person of interest who bought the same knife model was visually identified but excluded after DNA comparison.
May 27, 2024
The Setagaya Ward Assembly passed a motion promoting broader investigative use of DNA evidence in Tokyo.
The paradox
The computer use, food consumption, restroom use, and injury treatment indicate the offender remained in the house for hours with unusual composure after the killings.
The continuing police emphasis on the offender's clothing, bag, and shoes shows investigators still view the retained items as among the best remaining paths to identification.
Despite abundant non-victim blood, fingerprints, and personal items left behind, police have not publicly identified the offender.
The strongest public evidence remains biological and physical trace evidence rather than any single narrative about nationality, occupation, or institutional affiliation.
Blood type, DNA, fingerprints, clothing, a bag, and other retained items give investigators unusually concrete material without a matching person.
Compare what the evidence supports →Where certainty changes
Open each layer to see what the archive treats as core, contested, or unresolved.
Go deeper
This overview is the map. The case tabs hold the underlying events, people, media, locations, and source material.