Partially blind since birth, Matsumoto was enrolled in a school for the blind as a child. He graduated in 1977 and after failing the entrance exam for Tokyo University he turned to the study acupuncture and Chinese medicine. He married in 1978.
In the early 1980s he joined Agonshu, a 'new age' group. In 1987 he claimed to have experienced a revelation while in India, he also claimed to have found he had unique DNA. He changed his name to Asahara Shoko and formed his own group Aum Shinrikyo in 1987 using a mix of Buddhist and Hindu concepts for his belief system. The group was granted legal recognition as a religious group, after an appeal, in 1989. Also in that year he founded Shinrito, the political arm of his group.
Following the abject failure of Shinrito in the 1989 elections the group turned inwards and Asahara became more melodramatic. Predicting Armageddon and claiming to be the reincarnation of Shiva he ordered his followers to build nuclear shelters and remove themselves from external distractions. Some time between 1990 and 1993 Asahara ordered the production of chemical weapons, including sarin.
In 1994 the group announced the formation of an independent Aum government and also released noxious gases on two occasions. On March 20, 1995 ten members of Aum released sarin on the Tokyo subway, particularly in Kasumigaseki Station. There were further smaller attacks towards the end of the month. Between March and May 200 Aum adherents were arrested, Asahara was uncovered in a concealed room in Aum property in Kamikuishiki.
Asahara is currently in Japanese custody and faces 27 murder counts in 13 separate indictments, mainly the Tokyo attack but also individual murders of Tsutsumi Sakamoto (an anti-Aum lawyer) and Kiyoshi Kariya (a notary). He initially refused to enter a plea and it was not until April 1997 he offered a "not guilty", placing the blame for the deaths on his followers. Prosecutors demanded the death penalty when they presented final arguments on April 24, 2003; ten members of the cult have already been sentenced to death. His defence lawyers presented their final arguements in early November 2003.
A verdict is expected in late February 2004.