The Hiroshima District Court on Friday sentenced a man to life in prison as sought by prosecutors for a vehicular rampage at a Mazda Motor Corp. plant complex in Hiroshima Prefecture in 2010 that killed one employee and injured 11 others.

Presiding Judge Koji Inaba said defendant Toshiaki Hikiji, 44, had a delusional disorder but could be held culpable, dismissing the defense argument that he was mentally incompetent.

His actions were also swayed by his personality and philosophy of life, and constituted a "premeditated, ruthless and extremely dangerous crime," Inaba said.

Hikiji killed Hiroshi Hamada, 39, and attempted to kill 11 other male employees of Mazda by hitting them with a car at the company's adjoining two-plant complex, which straddles the city of Hiroshima and the town of Fuchu, on the morning of June 22, 2010, two months after he retired as a seasonal worker at the plant.

In the lay judge trial, the defense argued that while he may have driven recklessly on the plant premises, he was not competent enough to be held criminally liable based on the Penal Code, which states an act of insanity is not punishable.