Ikuo Hayashi, the former chief doctor for Aum Shinrikyo, was handed a life prison term Tuesday for committing mass murder in the March 1995 Tokyo subway nerve gas attack, even though the judge said he "deserves the death penalty due to the gravity of the crime."

Presiding Judge Megumi Yamamuro of the Tokyo District Court said he could not pass a death sentence because Hayashi helped investigators when he confessed to his role in the gassing and because he had showed deep remorse in court.

"Due to the nature of the crime, no other option but capital punishment can be considered for the defendant," the judge said, describing the sarin attack as indiscriminate and an inhumane act of terrorism that ignored the dignity of human beings.