• Chunichi Shimbun


This is the first of a three-part series.

After already having served a 12-year prison sentence following her conviction for murdering a patient, former assistant nurse Mika Nishiyama, 40, is expected to finally be acquitted on March 31.

The retrial concluded on Feb. 10, with prosecutors not recommending a sentence and saying they would not prove her guilt, essentially signaling her imminent acquittal.

The incident involves the May 2003 death of a 72-year-old male patient in a vegetative state at a hospital in Higashiomi, Shiga Prefecture. Nishiyama was 24 years old at the time of the incident and working as an assistant nurse there.

Nishiyama was arrested after she admitted during police interrogation to killing the patient by pulling out his respirator tube. But she later retracted her confession, claiming it was coerced by interrogators.

She consistently maintained during her trial that she was innocent, but the court ruled the initial confession credible and handed down a 12-year jail term in 2005.

Her requests for a retrial, made in 2010 and 2012, were dismissed a total of four times at various judicial levels, including the Supreme Court.

Four months after she finished serving her prison term in August 2017, the Osaka High Court accepted her request and granted her a retrial.

In December 2017, the high court ruled that it was possible the patient died from natural causes based on new evidence submitted by the defense team, which included a doctor’s opinion that pointed to arrhythmia as a possible cause of death.

The high court’s ruling to reopen the case was finalized at the Supreme Court in March 2019, and the first hearing of the retrial was held on Feb. 3 this year at the Otsu District Court, in which the prosecutors chose not to contest the new evidence.

This three-part series, based on investigative reporting by the Chunichi Shimbun that won the Waseda Journalism Award in November, focuses on the case by looking into more than 350 letters Nishiyama wrote to her parents claiming her innocence during her 12 years in prison.

The investigative reporting team also had a doctor well-versed in developmental and intellectual disabilities examine Nishiyama during her time in prison, concluding that she has the intellectual ability of a 9- to 12-year-old. The doctor also diagnosed her as having ADHD, or attention deficit hyperactivity disorder, and as being on the autism spectrum.

“This case has many lessons that Japan’s justice system needs to learn from,’’ said Kenichi Ido, Nishiyama’s defense lawyer.

To prevent vulnerable suspects, including those with mental disabilities, minors and foreign nationals, from making false confessions, having a lawyer present during police interrogation may be the only way, Ido said.

The ages of people that appear in the articles are those at the time of the original publication in May 2017.

Many defendants of criminal cases in Japan are found guilty solely based on confessions, and few are found not guilty even if they later retract their confessions, typically made during the period after arrest.

And in some cases, a lack of understanding of suspects and defendants with developmental or intellectual disabilities has led to miscommunications and misunderstandings during interrogations and trial sessions, even resulting in wrongful convictions.

Nishiyama’s case is no exception.

Throughout the interrogation and court proceedings, however, no consideration whatsoever was given to the possibility of Nishiyama having mental disabilities.

“(Asking for) a retrial is exhausting. But I haven’t killed anyone. But I can’t get out of jail. I’m so frustrated,” she wrote in June 2016 in one of about 350 letters to her parents while she was in Wakayama Prison.

When the patient died in 2003, police initially investigated the case as professional negligence resulting in death, suspecting that nurses failed to notice the alarm going off from his respirator that indicates that the tube had been detached. But there were no accounts of anyone hearing the alarm.

The only one to confess

A year later, however, while she was being interrogated by a police investigator in his 30s, Nishiyama started saying the alarm did go off.

“Since he told me that the alarm must have gone off, I lied,” she said in an April 2006 letter, adding that she became frightened because he yelled at her.

The police officer, who had been subjected to disciplinary action in a separate case for grabbing the chest of a suspect and kicking him during interrogation, was also good at playing the “good cop” depending on the situation.

“Then he suddenly became kind, and started talking about various things including his private life. He trusted me and he listened to me when I spoke about various things,” she said.

Since she performed poorly at school, Nishiyama had an inferiority complex toward her two older brothers, who graduated from prestigious universities. She also had difficulty building relationships and felt deeply isolated because she felt she didn’t have any friends.

“I had feelings for the police officer and I was desperate to get his attention,” she wrote in a May 2007 letter.

But due to her false statement about the alarms, police began conducting harsh interrogations on a fellow nurse who had cared about her. Upset by that, Nishiyama went to the police station and asked that her statement be withdrawn, only to be turned down.

Exasperated, she confessed to something that even investigators didn’t expect.

“I pulled out the tube for the respirator,” she said. In prison, she wrote: “I was told that the nurse was a single mother and that she had been interrogated until late at night because she was gravely responsible, and I felt sorry for her. I thought if I was held responsible, I could help her out of this.”

The police believed Nishiyama’s confession and arrested her in 2004 on suspicion of murder. The police claimed that she committed the crime because she was discontent with how assistant nurses — a position that doesn’t require qualifications — had been treated there.

“The officer asked me whether I had any complaints about the hospital and I answered. … he made up a story, and although I was thinking I had never intended to kill anyone, since he was nicer than ever to me, I went soft,” she wrote in the notes in prison.

Romantic feelings

During the trial, Nishiyama’s feelings toward the police investigator were revealed.

On one occasion, Nishiyama placed her hand over the officer’s during interrogation.

Just before she was transferred to prison, she clung to him and said, “I don’t want to be apart from you. I want to be with you more.” The officer didn’t stop her and patted her on the shoulder saying, “Hang in there.”

At the officer’s request, she wrote a written statement to prosecutors stating that even if she pleads not guilty in court, it is not her real intention.

There are 38 interrogation documents referring to her confessions, which changed again and again, and 56 reports and notes that she wrote herself. But she was pronounced guilty at the district court, and her 12-year prison sentence was finalized after her appeals to a higher court and the Supreme Court were both dismissed.

The decisions were all made based on the assumption that no one would lie and say that they had killed someone. But should that be applicable to her case?

Teachers at a junior high school Nishiyama attended decades ago say they had suspected she had intellectual disabilities back then.

“She was not able to express herself well. If she was a student today, we might have suspected her of having developmental disabilities,” said Hideki Yoshihara, 73, who was a deputy principal at Nishiyama’s school. “There were some concerns over her intellectual capabilities.”

Shoichi Ito, 69, who was in charge of student counseling at the school at the time, said: “She had difficulty communicating with others, and she was always alone. I wouldn’t deny the possibility of her admitting to doing something she hadn’t done.”

How the case progressed through the courts

  • May 22, 2003: A comatose patient dies at a hospital in Higashiomi, Shiga Prefecture.
  • July 2, 2004: Mika Nishiyama, who worked as an assistant nurse at the hospital, tells investigators that she pulled out a tube attached to the patient’s respirator.
  • July 6: Police arrest Nishiyama.
  • July 27: Prosecutors indict her on a murder charge.
  • Nov. 29, 2005: Nishiyama is given a 12-year prison term from the Otsu District Court.
  • Oct. 5, 2006: The Osaka High Court dismisses the defendant’s appeal.
  • May 21, 2007: The Supreme Court dismisses the appeal, finalizing Nishiyama’s sentence.
  • Sept. 21, 2010: Nishiyama’s defense team files for a retrial.
  • March 30, 2011: The Otsu District Court dismisses the request.
  • May 23 : The Osaka High Court also rejects the request to reopen the case.
  • Aug. 24: The Supreme Court upholds the decision.
  • Sept. 28, 2012: Nishiyama’s defense team refiles for a retrial.
  • Sept. 30, 2015: The Otsu District Court dismisses the request.
  • Aug. 24, 2017: Nishiyama is released from prison after serving her sentence.
  • Dec. 20: The Osaka High Court orders a retrial.
  • Mar. 18, 2019: The Supreme Court upholds the Osaka court’s decision.
  • Feb. 3, 2020: The first hearing of the retrial is held at the Otsu District Court.
  • Feb. 10: In the second and last hearing of the retrial, prosecutors say they would not prove her guilt, essentially signaling her acquittal.
  • Mar. 31: The Otsu District Court is expected to hand down a not guilty verdict.

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