TOKYO (TR) – The 25th anniversary of the murder of four members of a family in Setagaya Ward is Tuesday.
The case remains unsolved. Relatives of the family and police are pinning their hopes for a resolution on a new investigative method that uses DNA, reports TV Asahi (Dec. 27).
On December 31, 2000, Mikio Miyazawa, 44, his wife, 41-year-old Yasuko and their two children — 8-year-old daughter Niina and 6-year-old son Rei — were found dead inside their residence in the Kamisoshigaya area.
Since then, police have dedicated significant resources to the case but no significant clues have been found.
On December 26, parties connected to the case gathered at the home, which remains largely unchanged. Flowers, drinks and other offerings are still being placed in front of a fence along the property.
Praying at the scene was Takeshi Tsuchida, who was working in the Tokyo Metropolitan Police’s Forensic Science Division at the time.
Tsuchida, 78, said, “First of all, I’m sorry. I feel frustrated that we weren’t able to solve this case.”
“A murder scene unlike any other I’d seen”
The crime was extremely brutal. The perpetrator entered the home through the bathroom window and strangled Rei, who was on the mezzanine floor. He then stabbed Mikio, who was on the first floor, with the knife he was carrying. He later killed Yasuko and Nina, who were in the loft.
Tsuchida said, “The injuries were so brutal. It was a murder scene unlike any I’d ever seen before, and I felt that very strongly.”
Furthermore, the perpetrator did not immediately leave the scene. For some reason, he remained in the house and ransacked the interior. In addition to scattering documents in the bathtub, he is also known to have eaten ice cream from the freezer and used a home computer.
The perpetrator is described as a thin man, standing approximately 170 centimeters tall. He suffered a hand injury during the crime. Bloodstains left at the scene indicate that his blood type is A.
Tokyo police identified the perpetrator’s clothing, bag and other pieces of evidence (X)
“Memories fade over time”
Despite investigators knowing the perpetrator’s fingerprints, clothing and bag and having other crucial pieces of evidence, the case remains unsolved.
A current investigator says about the current status of the investigation. “Although the memories of those involved may fade over time, there is evidence directly connected to the perpetrator. So it is important to continue questioning those who have emerged as suspects in the investigation,” said superintendent Yoshimasa Kujirai of the Special Investigations Division in the Tokyo Metropolitan Police Department’s First Investigative Division.
As the hurdles to solving cases grow higher with time, one case that remained unsolved for more than two decades took a turn earlier this year. In November 1999, Namiko Takaba, then 32, was murdered in an apartment in Nagoya.
In October, Kumiko Yasufuku, a high school classmate of her husband, Satoru, was arrested. The deciding factor was a DNA match between the suspect and bloodstains found at the crime scene.
An intruder murdered four members of the Miyazawa family at their residence in Setagaya Ward on December 30, 2000“Closer to the truth”
DNA also holds the key to solving the Setagaya case. A letter from Mikio Miyazawa’s mother, Setsuko, was read aloud at a rally held in Tokyo on December 13.
“The other day, I read the news that the perpetrator in the Takaba case had been arrested,” she wrote. “It gave me a renewed sense of hope that we can get closer to the truth, even after such a long time. In other countries, DNA has been used to create sketches of perpetrators and lead to their arrest, so I hope that Japan can do the same.”
In the United States, technology that estimates facial features from the perpetrator’s DNA left at the crime scene is being used in investigations.
Parabon NanoLabs sells composite images of suspects built on DNA. Referred to as DNA phenotyping, it is the process of predicting a person’s physical appearance and ancestry for forensic purposes.
Dr. Ellen Greytak of Parabon Nanolabs said, “We can predict a person’s eye color, hair color, skin color, and number of freckles. We can also estimate facial shape, such as whether their face is wide or long, and how high their nose is. We can create a sketch that closely resembles that person.”
This research institute has been working with law enforcement agencies across the United States since 2015, contributing to the resolution of over 200 cases to date. They claim to be able to accurately estimate faces by utilizing a private DNA database of over 20,000 individuals.
A DNA database can be used to recreate a suspect’s image from evidence found at a crime scene (X)Obstacles
However, there are two major obstacles to implementing this technology in Japan.
The first is legality. According to the National Police Agency, Japan currently has no laws specifically addressing the use of DNA in investigations. DNA is only used to identify whether the DNA type left at the scene matches that of a suspect. Meanwhile, the genetic information needed for DNA phenotyping is the ultimate form of personal information, and it has been pointed out that legal reform is essential for its use in investigations.
The other is the issue of accuracy.
“The accuracy of my research is still around 10 percent,” says professor Imanishi Nori of the Tokai University School of Medicine. “The margin of error is still large, and to reduce that margin of error, we need to significantly increase the amount of data.”
Recreating faces with greater accuracy requires a massive DNA database, but professor Imanishi only has data on around 300 people. He says it’s not easy to increase the accumulated data.
“Each subject signs a consent form before we collect the data,” says the professor. “We manage the data carefully in our lab, and we anonymize it so that it cannot be identified for use in research. Our goal is [to collect data on] thousands to tens of thousands of people. But we still have a hard time figuring out how to collect it.”
“Break through the barriers”
Such a method might be the only hope in solving the Setagaya case.
Setsuko Miyazawa said of the murders, “I pray that [the police] can tell me who the culprit is.”
Superintendent Kujirai of the Tokyo Metropolitan Police said, “We will continue to thoroughly investigate this case, so that we can break through the barriers that have been built up over the years.”
Persons with information on the case are advised to contact the Seijo Police Station at 03-3482-0110.
AloJapan.com