A couple was referred to prosecutors on Friday for allegedly killing their 4-year-old daughter by giving her a toxic substance and an antipsychotic drug at their Tokyo home last March amid growing suspicion that she had suffered repeated neglect.
Kenichi Hosoya, 43, and his wife, Shiho, 37, were arrested Wednesday after their daughter, Yoshiki, died with ethylene glycol and large amounts of olanzapine, a medicine prescribed for mental disorders, detected in her body.
Investigators believe that the couple neglected Yoshiki as nursery schools have given accounts of Yoshiki being unclean. They also believe the couple attempted to conceal the neglect by making the girl switch nursery schools five times between her birth in 2019 and her death, investigative sources said.
Yoshiki was found topless and lying on the family's living room floor when rescuers responded to an emergency call by the father on the morning of March 13, 2023. Marks on her back suggest the couple had abandoned her lying on the floor for a long time, according to the sources.
Investigators suspect the parents poisoned Yoshiki with ethylene glycol by making her consume an anti-freeze solution used in engine coolants. The substance is sweet and easily dissolves in water.
The substance was also detected in the body of Kenichi Hosoya's older sister, who died at age 41 in April 2018, and the police are investigating the circumstances surrounding her death after finding records of the couple's online purchases of anti-freeze additives and olanzapine around that time.
After seizing the suspects' computers and smartphones, the police found records of online searches for ethylene glycol, the antipsychotic drug olanzapine, and toxic aconite.
Kenichi Hosoya's parents also died in 2018, and he became the president of the operator of a Japanese-style inn in downtown Asakusa, Tokyo, succeeding his father. He also inherited from his father an apartment.
The investigators suspect Kenichi Hosoya had been in a dispute over the inheritance with his older sister.
Following their arrest, Kenichi Hosoya has denied murdering Yoshiki while Shiho Hosoya has remained silent.
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