The Nagoya High Court on Wednesday overturned a lower court conviction of a 39-year-old man from Gifu Prefecture charged with murdering his 60-year-old mother.
In handing down the not-guilty verdict, Presiding Judge Nobuaki Horiuchi said, "At the time of the crime, the accused was in a state of criminal insanity due to schizophrenia and was not responsible for his actions."
In April last year, the Gifu District Court sentenced the man to six years in prison.
"The accused repeatedly entered and then was discharged from a psychiatric hospital from around 1991, and was discharged shortly before the incident," Horiuchi said. "But (the accused) was controlled by serious hallucinations and illusions and did not have the ability to restrict his own actions."
The judge added that the man had stabbed his mother to death after hearing voices ordering him to do so.
According to Wednesday's ruling, the man killed his mother by stabbing her in the throat with a knife at around 2:30 a.m. on Oct. 16, 1998, at their home in Ogaki, Gifu Prefecture, following a quarrel.
The Gifu District Court ruled that the man had diminished responsibility at the time of the crime and sentenced him to six years in prison, although prosecutors had sought an eight-year term.
Shigenori Ishiguro, deputy public prosecutor at the Nagoya High Public Prosecutor's Office, said, "We would like to respond, having thoroughly considered the ruling."
Naoaki Funahashi, the man's lawyer, said that although his client's medical records -- which showed that the man was suffering from serious schizophrenia at the time of the crime -- were not adopted as evidence at the lower court, the records were considered by the high court during its deliberations.
The man now plans to enter a psychiatric hospital as soon as possible, Funahashi said.