Chronology of Aum developments
February 1984 -- Shoko Asahara forms Aum Shinsen no Kai.
July 1987 -- Aum Shinsen no Kai is renamed Aum Shinrikyo.
Nov. 4, 1989 -- Tsutsumi Sakamoto, a lawyer helping people with complaints against Aum, is slain along with his wife and 1-year-old son at their Yokohama home.
February 1990 -- Asahara and 24 other Aum members run in a House of Representatives election. All of them lose.
June 27, 1994 -- Aum members release sarin nerve gas in a residential district of Matsumoto, Nagano Prefecture, killing seven people and seriously injuring four others.
March 20, 1995 -- Aum members release sarin gas on Tokyo subway trains, killing 12 people and injuring more than 5,000.
May 16, 1995 -- Asahara is arrested.
April 24, 1996 -- Asahara's trial begins.
April 24, 1997 -- Asahara pleads not guilty to all charges except a VX nerve gas attack on a man.
Dec. 2, 1997 -- Prosecutors reduce the number of injuries in the subway attack indictment to hasten court deliberations.
Dec. 27, 1999 -- A law aimed at monitoring Aum goes into effect.
Jan. 18, 2000 -- Aum admits Asahara's involvement in the crimes for the first time. The cult renames itself Aleph.
Oct. 4, 2000 -- Prosecutors drop indictments in four of 17 cases.
March 13, 2003 -- Asahara refuses to speak in his first questioning in court.
March 27, 2003 -- Asahara remains silent at his second questioning session.
April 10, 2003 -- Asahara again declines to speak at his third questioning. Examination of evidence is concluded.
April 24, 2003 -- Prosecutors demand the death sentence for Asahara.
Oct. 31, 2003 -- Trial concludes; Asahara remains silent.
Feb. 27, 2004 -- Asahara sentenced to death.