The suspect in the murder of his Shinto priest sister at a Tokyo shrine last week sent about 2,800 letters insulting the victim to shrines across Japan, investigative sources said Friday.
Police suspect Shigenaga Tomioka, 56, held a fierce grudge against his 58-year-old sister Nagako for her ascension to the chief priest post at the Tomioka Hachimangu shrine. The letters demanded she be expelled from the shrine, the sources said.
Investigators believe Shigenaga murdered Nagako with a samurai sword and that his wife Mariko, 49, slashed the driver of the shrine’s car before Shigenaga killed his wife and then himself on the night of Dec. 7.
Two blood-covered samurai swords with 80- and 45-centimeter blades — and two survival knives — were found at the scene. The swords were purchased in Tokyo’s Taito Ward in September.
Before the incident, Shigenaga asked an acquaintance to drop some 2,800 letters into a post box outside Tokyo’s Koto Ward, where the shrine is located, the day after the attack, according to the sources.
Each letter was written on eight sheets of paper and had a thumb mark which matched Shigenaga’s fingerprint.
Shigenaga had served as the chief priest at the Tomioka Hachimangu shrine from 1995, but the siblings’ father returned to the post after the suspect resigned in May 2001 over money-related trouble, according to the Association of Shinto Shrines, which oversees about 80,000 shrines across Japan.
Nagako became the acting chief priest in 2010 in accordance with her father’s will and later requested the Association of Shinto Shrines approve her in the position.
The association, however, did not respond, prompting Nagako to withdraw the shrine from the administrative organization in September 2017, installing herself as chief priest.
Of the 2,800 letters, about 1,000 were addressed to shrine-related officials across Japan, and the remaining 1,800 were sent to restaurants, schools and other entities apparently linked to the Tokyo shrine’s parishioners.
Security camera footage and police investigations have found that Shigenaga and Mariko ambushed Nagako as she got out of a car on the grounds of the shrine.