The Setagaya Family Murders

A family of four was killed in Setagaya, Tokyo, at the end of 2000. The offender left extensive physical evidence, yet the case remains unsolved.

A family of four

On the night of 30–31 December 2000, Mikio and Yasuko Miyazawa and their two children were killed in their home in Setagaya, Tokyo. The crime was discovered the next morning and quickly became one of Japan’s best-known unsolved homicide cases.

An unusually evidence-rich scene

Investigators recovered a large amount of material believed to have been left by the offender, including clothing and biological evidence. Police concluded that the killer remained inside the home for a period after the murders, using items in the house before leaving.

A long-running police appeal

The Tokyo Metropolitan Police Department has continued to publicize the case, release information about evidence and offer a reward for information leading to an arrest. Advances in forensic testing have allowed investigators to revisit biological and trace evidence, but no suspect has been conclusively identified.

Why it remains so compelling

The Setagaya case is unusual because investigators possess more physical evidence than in many cold cases, yet the offender’s identity remains unknown. The gap between the volume of evidence and the absence of an arrest has kept public attention on the case for more than two decades.