The Tokyo High Court on Tuesday acknowledged that a 56-year-old man who killed a woman and seriously injured three members of her family when he torched their house was insane at the time and thus commuted his death sentence to a life term.

Kenshi Chiba set fire to the home of Toshiko Imahashi, 71, in Hitachi, Ibaraki Prefecture, on March 1, 2000, after his divorce because he blamed the Imahashi family for introducing him to his ex-wife, according to the court.

Imahashi was killed and three members of her family sustained serious burns.

Presiding Judge Toshio Yamada said, "It was a brutal crime, which could have killed everyone (in the house), and the defendant has not shown serious remorse."

At the same time, however, he added that "it is undeniable that the defendant was criminally insane and suffered from an obsessive-delusional disorder."

During his trial at the Mito District Court, Chiba denied any intent to kill. The lower court in March 2002, however, ruled that he had intent and his crime was extremely brutal, and thus he was sentenced to hang.

According to the court, Chiba fell into despair after his divorce, and decided to kill himself as well as his matchmakers.