TRUE CRIME ATLAS

Setagaya Family Murders

New releasePublished May 21, 2026Updated May 21, 2026

Overview

Case Overview

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.

Case At A Glance

Interrupted burglary escalated into a full-family murder

Low confidence

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Status
Unsolved
Key evidence
Investigators concluded that a sashimi knife used in the attack broke during the assault, an important detail in the reconstruction of how Mikio Miyazawa confronted the intruder.
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Open question
Was theft the original objective or only incidental after the murders?
Latest timeline item
May 27, 2024: Setagaya Ward motion on DNA usage

Key Facts

Status: Unsolved

Also known as: Setagaya family murder, Setagaya family killings, Miyazawa family murders, Setagaya massacre

Coverage: 11 timeline events, 6 persons, and 4 locations

Sources collected: 27 sources

Categories

unsolved homicidefamily homicidemass murderhome invasioncold caseJapan

Tags

DNAfingerprintsType A bloodbathroom window entrySoshigaya Parkcomputer activitybarley teaice creamMUJI handkerchiefsUNIQLO jacketSlazenger shoesrewardstatute of limitations

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