The 44-year-old man is still in hospital himself, suffering from gas poisoning. Police have found potassium cyanide and other chemicals in his house.
The gas suddenly descended on a small area of Matsumoto on Monday night. Panicked residents stumbled out into the streets, vomiting and coughing, as ambulances rushed in to take the most seriously ill to hospital. Five people died in their houses, and two more in hospital.
The man had been employed by an industrial chemical company in Kyoto, and held licences to handle hazardous chemicals. Police believe he was mixing chemicals for a home-made insecticide when a fatal reaction occurred, releasing enough gas to kill his neighbours.Reuse content