Hair Analysis Indicates Psychotropic Drug Likely Given to 4-Year-Old Prior to Death

The Yomiuri Shimbun

13:09 JST, February 27, 2024

A 4-year-old girl who was allegedly killed by her parents in Taito Ward, Tokyo, is suspected to have been given psychotropic drugs for about a year preceding her death, investigative sources said based on the result of hair analysis.

The Metropolitan Police Department suspects that Yoshiki Hosoya had been neglected for a long period of time while being given psychotropic drugs.

Yoshiki fell unconscious at home last March and was taken to a hospital where she died. Autopsy results indicated the presence of the psychotropic drug olanzapine and the automotive antifreeze agent ethylene glycol in her body. Her parents — company executive Kenichi, 43, and his wife, Shiho, 37 — were arrested on Feb. 14 on suspicion of killing their daughter. Kenichi has denied the allegations, and Shiho has not responded.

Analysis of the couple’s smartphones showed a history of purchasing olanzapine online from overseas vendors on several occasions starting about a year before Yoshiki’s death, as well as searches about the harmful effects of the drug on the human body, the sources said.

Shiho explained that she had bought and taken the olanzapine herself, but the MPD launched an investigation on the belief that Yoshiki had been given the drug, and an analysis of her hair indicated that Yoshiki had been given the drug for at least a year.

The MPD also found the couple had purchased antifreeze online several times between four months and a few days before their daughter’s death. The account used for the purchases was deleted after the incident, prompting the MPD to suspect they had tried to cover up their purchase history.

Before the incident, the couple had exchanged Line messages about Yoshiki, who is the couple’s second daughter, saying she was “hateful” and that they “wish she was not there.” The MPD is investigating the circumstances around why they treated her differently from her two siblings.

According to the Health, Labor and Welfare Ministry, olanzapine causes such side effects as drowsiness, and large doses can induce a coma. Ethylene glycol poses a risk of damage to the central nervous system and kidney function.