Kazuki Miyamoto, 37, was arrested on suspicion of murder in a case in which a woman who was a university student in Kita Ward, Kyoto died after ingesting highly toxic thallium. This was revealed in an interview with investigators. When she denied any involvement in her voluntary questioning before her arrest, she said, "When she started drinking (at the woman's house), her condition suddenly changed, so she bought medicine at the pharmacy and gave it to her." It was also found that he explained that The Osaka Prefectural Police believe that it was a trick to impersonate a third party who had no connection with the incident. Hinako Hamano (21 years old at the time), a third-year student at Ritsumeikan University, is said to have met Miyamoto, who runs an event planning company in Kyoto, at her part-time job.
Miyamoto is suspected of somehow ingesting thallium to a resident, Mr. Hamano, in a room in a condominium in Kita-ku, Kyoto on the morning of October 12, 2022. Ms. Hamano's condition suddenly deteriorated and she was rushed to a hospital in Osaka Prefecture, where she died three days later of acute respiratory failure associated with thallium poisoning.
According to investigative sources, on the evening of the 11th, the day before the incident, the two men went to Hamano's house after eating and drinking at a bar in Kyoto. The two started drinking again, and it is believed that thallium was mixed in around this time.
Regarding the situation when Mr. Hamano's physical condition suddenly changed during the interrogation before his arrest, Miyamoto explained, "Shortly after starting drinking, Mr. Hamano's cough did not stop, so I went to the pharmacy." Prefectural police have confirmed that Miyamoto actually purchased the drug at a pharmacy through security camera investigations and other means. On the other hand, based on the results of the judicial autopsy of the body, the prefectural police investigated the place and time when Hamano was forced to ingest thallium. There was no evidence that Hamano became unwell before returning home, and it was determined that there was no suspicion that a third party other than Miyamoto was involved. From the series of circumstances, it is possible that the purchase of the over-the-counter medicine was a disguise to emphasize Hamano's care.
