In October 1989,
Tokyo Broadcasting System Television (TBS) taped an interview with Sakamoto regarding his anti-
Aum efforts. However, the network secretly showed a video of the interview to Aum members without Sakamoto's knowledge, intentionally breaking its
protection of sources. Aum officials then pressured TBS to cancel the planned broadcast of the interview.
[5][6]
Several days later, on November 3, 1989, several Aum Shinrikyo members, including
Hideo Murai, chief scientist, Satoro Hashimoto, a
martial arts master, Tomomasa Nakagawa and
Kazuaki Okazaki drove to
Yokohama, where Sakamoto lived. They carried a pouch with 14
hypodermic needles and a supply of
potassium chloride. According to court testimony provided by the perpetrators later, they planned to use the chemical substance to
kidnap Sakamoto from Yokohama's
Shinkansen train station, but, contrary to expectations, he did not show up—it was a holiday (
Bunka no hi, or "
Culture Day"), so he slept in with his family at home.
At 3 a.m. on November 5, the group entered Sakamoto's apartment through an unlocked door. Tsutsumi Sakamoto was struck on the head with a hammer, injected with
potassium chloride, and strangled.
[7] His wife, Satoko Sakamoto (坂本都子
Sakamoto Satoko, 29 years old) was beaten and injected with potassium chloride.
[8] Their infant son Tatsuhiko Sakamoto (坂本竜彦
Sakamoto Tatsuhiko, 14 months old) was injected with the potassium chloride and then his face was covered with a cloth. The family's remains were placed in metal drums and hidden in three separate rural areas in three different prefectures (Tsutsumi in
Niigata, Satoko in
Toyama, and Tatsuhiko in
Nagano) so that in case the bodies were uncovered, police might not link the three incidents. Their bed sheets were burned and the tools were dropped in the ocean. The victims' teeth were smashed to frustrate identification.
[9] Their bodies were not found until the perpetrators revealed the locations after they were captured in connection with the
1995 Tokyo subway attack. By the time police searched the areas in which the victims were placed, their bodies were reduced to bones.
[10]