Hayato Imai was a care worker at a paid nursing home in Saiwai ward, Kawasaki, in Kanagawa Prefecture. In November and December 2014, three residents of the home died on separate dates: a man of 87, a woman of 86 and a woman of 96. Imai was arrested in February 2016 and tried for murder by a panel of professional and lay judges at the Yokohama District Court. In March 2018 the court found him responsible for all three deaths and sentenced him to death. The Tokyo High Court dismissed his appeal in March 2022. In May 2023 he withdrew his appeal to the Supreme Court, and the death sentence became final on May 11, 2023.
In Japanese order his name is Imai Hayato, written 今井隼人. His exact birth date is not on record. He was 21 at the time of the deaths and 25 when the first court sentenced him.
The home was a paid nursing home offering care services, in the Saiwai ward of Kawasaki. Imai joined its staff in the spring of 2014 as a care worker.
Three residents died there on separate dates within about two months. The first was a man of 87, in early November 2014. The second was a woman of 86 on December 9, 2014. The third was a woman of 96 on December 31, 2014. The three were elderly people who needed nursing care.
The court treated each death as a separate act and sentenced Imai for all three.
Suspicion fell on Imai in September 2015, and he denied any involvement at the time. Police arrested him in Kawasaki on February 15, 2016, and he was charged with three counts of murder.
After his arrest he admitted all three killings to police and described a habit of distorting the truth. This confession became the center of the trial, because he later withdrew it.
The case was heard as a lay-judge trial (saiban-in saiban) at the Yokohama District Court, with Judge Hidetaka Watanabe presiding. The court held 22 hearings. The prosecution asked for the death penalty.
Imai pleaded not guilty. He retracted the statements he had made to police. His defense said the confession was false and had been obtained under pressure, that there was no objective evidence against him, and that the deaths could have been accidents or suicides. The defense asked for an acquittal. Testimony at the hearings dealt with his character and upbringing: his mother said she had been deceived many times, and his sister spoke of many small lies. On the witness stand he acknowledged that he often lied and described his lying self as a "fabricated self."
On March 22, 2018, the court gave its verdict. It found him responsible for all three deaths and held that they were not accidents or suicides. It found that the residents could not have caused their own deaths given their physical condition, and that nothing showed that any other member of staff was involved. It found the confession to police credible. It also found that Imai was fully responsible for his actions. The court sentenced him to death, as the prosecution had asked. His lawyers appealed on the same day.
The appeal to the Tokyo High Court began on December 20, 2019, and Imai maintained his innocence.
On March 9, 2022, the Tenth Criminal Division of the Tokyo High Court dismissed the appeal. The defense had argued that evidence, including the confession, had been wrongly admitted and that the deaths could have been accidents or suicides. The High Court rejected both lines of argument and left the death sentence in place.
Imai's defense lawyers then filed an appeal to the Supreme Court. Imai himself withdrew it, with effect on May 11, 2023, and from that day the death sentence was final. The withdrawal became public on May 15, 2023. No reason for the withdrawal is on record.
Since May 11, 2023 Imai has been under a final sentence of death in Japan. The sentence still stood in December 2024, and no execution of Imai had been reported by November 9, 2026.
His birth date and his reason for withdrawing the final appeal remain unknown. No other deaths are charged against him or attributed to him.
2014, spring: Imai joins the staff as a care worker.
2014, early November: first resident (a man aged 87) dies.
2014, December 9: second resident (a woman aged 86) dies.
2014, December 31: third resident (a woman aged 96) dies.
2015, September: suspicion falls on Imai; he denies involvement.
2016, February 15: arrested in Kawasaki and later charged with three counts of murder.
2018, March 22: Yokohama District Court sentences him to death; his lawyers appeal the same day.
2019, December 20: appeal hearings begin at the Tokyo High Court.
2022, March 9: Tokyo High Court dismisses the appeal.
2023, May 11: Supreme Court appeal withdrawn; death sentence final.
2023, May 15: the finality of the sentence becomes public.
2026, November 9: no execution of Imai has been reported.