Eight people were killed[1][3] and more than 500 were harmed by sarin aerosol that was released from a converted refrigerator truck in the Kaichi Heights area.
The sarin attack occurred in a quiet residential area in the city of Matsumoto, Nagano Prefecture.
[4] Residents of Matsumoto had also angered Aum founder Shoko Asahara by vigorously opposing his plan to set up an office and factory in the city's southern area.
Opponents of the plan gathered 140,000 signatures on an anti-Aum petition, equivalent to 70 percent of Matsumoto's population at the time.
At 10:40 pm, members of Aum used a converted refrigerator truck to release a cloud of sarin which floated near the home of the judges.
The patients were suffering from darkened vision, eye pain, headaches, nausea, diarrhea, miosis (constricted pupils), and numbness in their hands.
"[8] After the incident, police focused their investigation on Yoshiyuki Kōno, whose wife was a victim put in a coma by the aerosol.
Thirteen Aum members, including cult leader Shoko Asahara, were sentenced to death, and were executed in 2018.