How Japanese Nurse Ayumi Kuboki Slowly Murdered Some Of Her Patients

The Independent writes that an autopsy was performed on Yamaki and it was concluded that he had been poisoned with an antiseptic solution. Per the Daily Mail, an autopsy was then performed on Nishikawa. He too had died from the same poison. A subsequent investigation began at the hospital and officers discovered several punctured IV bags (via the New York Post). It was determined that Yamaki and Nishikawa’s killer had likely inserted the poison with a syringe. The police decided to inspect the nurses’ uniforms and traces of the antiseptic were found only on Kubokis. When she was arrested and questioned, Kuboki confessed to her crimes.

She stated (via the Independent) that she poisoned “about 20 patients” including Yamaki and Nishikawa, by injecting antiseptic into their IV bags. According to the New York Post, the antiseptic Kuboki used contained a chemical called benzalkonium chloride. VICE reported that Kuboki disclosed that she was “mentally and physically exhausted” from being a nurse. Furthermore, she explained that she opted to kill patients that she believed were near death.

According to the Independent, she did not want them to die during her shift. If they did, Kuboki was tasked with breaking the news to family members and she wanted to avoid this at all costs. Kuboki noted (via the Independent), “It would be troublesome if that responsibility fell on me.” Thus, she killed her patients while there was still another nurse on duty. Kuboki, for example, poisoned Nishikawa before the start of her shift.