Ayumi Kuboki (久保木愛弓, born April 10, 1987) is a Japanese spree killer, suspected serial killer and former nurse who was convicted of killing three patients at the Oguchi Hospital in Yokohama using diamitol, all of which occurred September 2016.[2] She is currently serving a life term, and remains under investigation for up to 48 total deaths that occurred at the hospital dating to July of that year.

Ayumi Kuboki
Born1987 (age 36–37)
Conviction(s)Murder x3
Criminal penaltyLife imprisonment
Details
Victims3+
Span of crimes
September 15 – 19, 2016 (confirmed)
CountryJapan
State(s)Kanagawa
Date apprehended
June 2018

The Kanagawa Prefectural Police have designated this as the Oguchi Hospital Inpatient Murder Case, while the Kanagawa Shimbun named it the Oguchi Hospital Continuous Drip Murder Case.

Background

edit

Investigation

edit

In September 2016, a nurse tending to a patient at the Oguchi Hospital accidentally dropped an infusion bag, causing the solution inside to begin foaming.[3] As it was not supposed to do that, it was examined further, with the doctors discovering that it had been mixed with diamitol.[4] Fearing a possible contamination, all IV bags on the building's premises were checked, leading to the discovery that one of the bags administered to 88-year-old Nobuo Yamaki, a patient who had died two days prior had been tampered with.[5] Upon inspection, nurses found a hole pierced with a fine needle in the protective filter that seals the rubber stopper, which was the case with about ten other such bags.[3] As it was feared that this might have affected other recent deaths at the hospital, which amounted to an unusually high amount of 48 since July, staff contacted Kanagawa Prefectural Police for assistance.[5][6] An investigation concluded that somebody had intentionally inserted foreign substances into the bodies of the patients and deliberately killed them by mixing it in with the IV bags, and so, a special inquiry was started in order to resolve the case.[4]

The diamitol used for the crime was used for business purposes and was placed at various places in the hospital, making it extremely difficult to identify the culprit.[4] To resolve this, the police carried out an appraisal of what the hospital's inventory, and an examination of the employees' clothes at the time revealed traces of diamitol in the pockets of Ayumi Kuboki.[7] In addition, during the night shift immediately after the incident was discovered, a security camera installed by the prefectural police showed her walking around the hospital with a drug that she was not assigned to administer.[8] She was zeroed in as the prime suspect after a colleague claimed that he had seen her enter the room of a patient to whom she was not assigned—soon after she left, his condition worsened and he died.[9]

Arrest

edit

At the end of June 2018, the prefectural police began to interview Kuboki based on the circumstantial evidence they had gathered up until then.[10][11] During the interview, she readily admitted to infusing the bags of at least 20 patients with diamitol. As a result, she was arrested and charged with murder on July 7. On July 28, she was charged with an additional murder concerning the death of another patient in September 2016, who died after the antiseptic solution was mixed in with his drip.[12] After her arrest, however, Kuboki, who was interviewed by several TV stations and newspapers, sent handwritten letters in which she denied responsibility.[13]

She later retracted those statements, admitting that her motive for killing the patients was her fear of explaining the deaths to their family members.[13][14] Kuboki also claimed that on one occasion, after a colleague blamed her for the death of a patient, she constantly thought about killing him outside of working hours.[15]

Before the murders occurred, there were reports of vandalism at the ward, with items being stabbed with needles or going missing, and robes being torn.[3] Kuboki herself claimed that fellow nurses frequently gossiped and complained about various problems relating to their patients or relatives, which sometimes even led to arguments.[16] Due to multiple accusations relating to verbal abuse and neglect of patients, multiple nurses working at the hospital resigned from their posts.[17] These allegations were corroborated by the family members of some victims, who claimed that they had witnesses them arguing between one another, and that one nurse had yelled at their relative while they were visiting him.[18]

In interviews, she claimed, according to psychiatrist Tamami Katada, Kuboki's true motive might have been a way to exact revenge on her colleagues and bosses: by killing patients during the working hours of other nurses, she would cause problems and eventually a scandal that would lead to their ruin.[19]

Trial

edit

On December 7, 2018, Kuboki was charged with 5 counts of premeditated murder relating to the deaths of three patients who died between September 15 and 19, 2016.[20] A sixth charge relating to the death of a fourth patient was dismissed on the grounds that his death might have been caused by accident, as his infusion bag had been accidentally contaminated with diamitol while she was trying to kill another patient. The charges were filed before the Yokohama District Court, with the presiding justice being Majordomo Kazunori.[21]

First instance

edit

The trial began on October 1, 2021. The prosecutorial side argued for the death penalty, claiming that the defendant was fully aware of her actions, while her attorneys claimed that she was in a state of diminished responsibility due to her schizophrenia.[20][22]

The final judgment was delivered on November 9, with the Yokohama District Court recognizing that Kuboki was autistic, which was recognized as a mitigating factor. However, they rebuked the claims that her schizophrenia affected her judgment, finding that she was legally sane at the time when she committed the murders.[23] As a result, she was found guilty and sentenced to life imprisonment.[21] The verdict proved unsatisfying for both the prosecutors and the attorneys, both of whom are currently appealing the sentence to the Tokyo High Court.[24]

Response from Oguchi Hospital

edit

Prior to the incident, the Yokohama City Council received multiple complaints about issues relating to the hospital, due to which they installed a third-party committee to evaluate conditions at the establishment. In the report, titled "Verification Report on Medical Safety Operations in Yokohama City (Regarding Responses to Large Hospitals)", the committee concluded that they had no authority to either inspect or guide the hospital's actions due to statutes of the Medical Care Act, which created a "system gap" between the council and the hospital administration. As a result, they suggested that a request be made to the national government for improvement in regards to this issue.

On the hospital's side, in spite of the allegations of misconduct dating back to June, the director said that he initially thought it should be dealt with at the hospital, but as things got out of hand, he had to resort to contacting the prefectural police.[25] Since the incident, the Oguchi Hospital was renamed to the Yokohama Hajime Hospital.

See also

edit

References

edit
  1. ^ "【呪われた病院】ヤバすぎる"看護"の実態【大口病院連続点滴中毒死事件】". YouTube. 7 July 2023.
  2. ^ Kanoko Tsuchiya (November 9, 2021). "元看護師に無期懲役判決 患者連続死事件、責任能力認めつつ死刑回避" [Former nurse sentenced to life imprisonment for consecutive deaths of patients, avoiding the death penalty while acknowledging responsibility]. Asahi Shimbun (in Japanese). Archived from the original on November 10, 2021.
  3. ^ a b c "新証言 点滴異物混入事件 内部に詳しい人物の可能性は?" [New testimony on the intravenous foreigh matter contamination case: What is the possibility of an insider being responsible?]. NHK (in Japanese). October 2016. Archived from the original on October 9, 2016.
  4. ^ a b c "「県警の歴史で最も難しい事件の一つ」大口病院・点滴連続殺人事件1年" ['One of the most difficult cases in the history of the prefectural police' One year after the serial murders in Oguchi Hospital]. Kanagawa Shimbun (in Japanese). September 29, 2017. Archived from the original on October 2, 2017.
  5. ^ a b "異物投与され入院患者が死亡、殺人容疑で捜査 横浜" [Inpatient died after foreign body was administered, murder investigation initiated in Yokohama]. The Asahi Shimbun (in Japanese). September 23, 2016. Archived from the original on September 23, 2016.
  6. ^ "大口病院の点滴殺人 2カ月で48人死亡も44人は自然死扱いに" [48 people died in 2 months from poisoning in hospital...Still, all but 4 were treated as natural deaths, explained by Taihei Ogawa]. Livedoor (in Japanese). July 10, 2018. Archived from the original on July 11, 2018.
  7. ^ "決め手は看護服のポケット、消毒液成分付着 連続中毒死" [The decisive factor is the pocket of the nursing clothes, the attachment of antiseptic solution components, continuous poisoning deaths]. The Asahi Shimbun (in Japanese). July 7, 2018. Archived from the original on July 7, 2018.
  8. ^ "防犯カメラに「インスリン手に院内巡回」" ['Patrolling around the hospital with insulin in hand' on the security camera]. Mainichi Shimbun (in Japanese). July 11, 2018. Archived from the original on July 11, 2018.
  9. ^ "横浜「大口病院」、事件発覚以降に死亡患者が激減 捜査は難航" [Yokohoma 'Oguchi Hospital's number of dead patients has decreased sharply since the incident was discovered. Investigation is difficult.]. Daily Shincho (in Japanese). December 8, 2016. Archived from the original on December 8, 2016.
  10. ^ "病室に逮捕の女 5分後急変 横浜・連続点滴中毒死" [A woman arrested in a hospital room suddenly charged 5 minutes later]. Fuji News Network (in Japanese). July 8, 2018. Archived from the original on July 11, 2018.
  11. ^ "31歳元看護師を逮捕 殺人容疑で神奈川県警" [31-year-old former nurse arrested by Kanagawa Prefectural Police on murder charges]. Mainichi Shimbun (in Japanese). July 7, 2018. Archived from the original on July 7, 2018.
  12. ^ "点滴中毒死、元看護師を再逮捕" [Former nurse re-arrested in intravenous poisoning deaths]. Reuters (in Japanese). July 28, 2018. Archived from the original on July 28, 2018.
  13. ^ a b "「犯人を絶対許せません」 元看護師 逮捕前 直筆400文字の手紙" ['I can't forgive the criminal' Former nurse's 400-character letter before arrest]. Fuji News Network (in Japanese). July 9, 2018. Archived from the original on October 2, 2021.
  14. ^ "大口病院・20人殺害か…久保木容疑者、他の看護師への復讐願望を患者に「置き換え」か" [20 people dead at Oguchi Hospital...Suspect Kuboki 'placed' desire for revenge against other nurses on patients?]. Business Journal (in Japanese). July 11, 2018. p. 1. Archived from the original on January 9, 2022.
  15. ^ ""落ち度"指摘され消毒液混入か" ['Failure' is pointed out, and was it mixed with disinfectant?]. NHK (in Japanese). July 10, 2018. Archived from the original on July 13, 2018.
  16. ^ "点滴殺人の大口病院 現場病棟で看護師同士のいじめトラブル" [Bullying trouble between nurses in the on-site ward of a large hospital for drip murder]. News Post Seven (in Japanese). October 20, 2016. p. 1. Archived from the original on January 9, 2022.
  17. ^ "点滴殺人の病院でいじめか、看護師が次々と辞めていく…" [Bullying at the hospital with patient murders, nurses quit one after another...]. Livedoor (in Japanese). October 16, 2016. Archived from the original on October 17, 2016.
  18. ^ "点滴殺人の大口病院 現場病棟で看護師同士のいじめトラブル" [Bullying trouble between nurses in the on-site ward of a large hospital for drip murder]. News Post Seven (in Japanese). October 20, 2016. p. 2. Archived from the original on January 9, 2022.
  19. ^ "大口病院・20人殺害か…久保木容疑者、他の看護師への復讐願望を患者に「置き換え」か" [20 people dead at Oguchi Hospital...Suspect Kuboki 'placed' the desire for revenge against other nurses on patients?]. Business Journal (in Japanese). July 11, 2018. p. 2. Archived from the original on January 9, 2022.
  20. ^ a b "旧大口病院の連続中毒死、元看護師に死刑求刑…遺族「久保木さんの保身のために死んだ」" [Death sentence sought for former nurse at Oguchi Hospital...The bereaved family 'died for the protection of Mrs. Kuboki']. Yomiuri Shimbun (in Japanese). October 22, 2021. Archived from the original on January 9, 2022.
  21. ^ a b "「横浜・旧大口病院点滴殺人 元看護師に無期懲役判決 責任能力認定も「死刑に躊躇」」" [Former nurse at Oguchi Hospital sentenced to indefinite imprisonment, courts hesitant to give death penalty]. Kanagawa Shimbun (in Japanese). November 9, 2021. Archived from the original on January 9, 2022.
  22. ^ "横浜・旧大口病院点滴中毒殺人 元看護師、起訴内容認める" [Former Oguchi Hospital nurse admits guilt in indictment]. Kanagawa Shimbun (in Japanese). October 1, 2021. Archived from the original on October 1, 2021.
  23. ^ "元看護師は「更生の道が相当」 無期懲役判決で横浜地裁" [Former nurse sentenced to life imprisonment by Yokohama District Court: 'the road to rehabilitation is appropriate']. Sankei Shimbun (in Japanese). November 9, 2021. Archived from the original on January 9, 2022.
  24. ^ "入院患者3人の中毒死事件、検察・弁護側が控訴 無期懲役判決に不服" [The prosecution / defense dissatisfied with life imprisonment sentence in deaths of three inpatients, appeal case]. Asahi Shimbun (in Japanese). November 22, 2021. Archived from the original on January 9, 2022.
  25. ^ "点滴混入殺人「大口病院」看護師たちにトラブル?風評恐れて警察届けず" [Trouble with nurses at Oguchi Hospital led to murder case? 'I'm afraid of rumors and didn't report it to the police']. J-Cast News (in Japanese). September 16, 2016. Archived from the original on January 9, 2022.
edit