Photo/Illutration The headquarters of Tokyo's Metropolitan Police Department (Asahi Shimbun file photo)

Tokyo prosecutors indicted one of two parents on charges of murdering their 4-year-old daughter, the fourth family member who died from poisoning.

Shiho Hosoya, 38, is accused of murdering her daughter, Yoshiki, in March 2023 at their home by administering olanzapine, an antipsychotic drug, and ethylene glycol, a toxic substance commonly used in automotive antifreeze.

The girl, who had shown signs of abuse and neglect, had no medical reason to take olanzapine.

Hosoya’s husband, Kenichi, 44, was also arrested last year on suspicion of murdering Yoshiki. But he was not indicted over her death.

The March 31 announcement by the Tokyo District Public Prosecutors Office did not provide a reason.

According to investigative sources, Kenichi was away around the time his daughter was being poisoned, and the girl had been left alone with Hosoya at their home in Tokyo’s Taito Ward.

The sources also said there was no clear motive for Kenichi to kill Yoshiki.

After the couple were arrested in February last year over Yoshiki’s death, the mother initially remained silent while the father denied the allegations.

Investigators also uncovered earlier suspicious deaths of Kenichi’s parents and sister, which occurred within a span of just six months in 2018.

An analysis of the sister’s biopsy sample and the parents’ medical records revealed signs of ethylene glycol consumption.

This led to fresh arrests of the couple on suspicion of murdering the three adults.

The couple have also been accused of swindling insurance payments following the death of Kenichi’s father.

Investigators believe a dispute over the family business and financial issues played a part in the killing of the three adults.

(This article was written by Shomei Nagatsuma, Hiromichi Fujita and Minami Endo.)

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