By any reasonable legal measure, Iwao Hakamada should not have lived to see his conviction for murder overturned.

The former boxer, who spent almost half a century on death row after being convicted of killing a family of four in the late 1960s, was acquitted last week in one of the most closely watched miscarriages of justice in postwar Japan.

Hakamada spent more than 45 years on death row – longer than any other prisoner worldwide – believing that each day could be his last after his sentenced was finalised in 1980. Yet he would spend another 34 years in detention as his lawyers petitioned for a retrial – a process that does not guarantee a stay of execution in Japan’s opaque criminal justice system.

He became the fifth condemned convict in postwar Japan to be found not guilty in retrials. Others have been executed while their lawyers lobbied for their case to be heard again in court.

While his exoneration, after decades of campaigning by his 91-year-old sister, Hideko Hakamada, triggered calls in the Japanese media for changes to the lengthy and complicated retrial process, campaigners said his case highlighted the risk posed by capital punishment.

Government officials point to strong public support for the death penalty, with a 2019 survey by the cabinet office showing 80% of respondents believing it was “necessary in some cases” and just 9% calling for its abolition.

Campaigners, however, have questioned the wording of opinion polls and widespread lack of awareness of how executions are carried out.

“Analysis of opinion polls, including in Japan, has shown that the support for the death penalty can be greatly affected by the methodology used or the timing of the survey,” says Chiara Sangiorgio, Amnesty International’s campaigner against the death penalty.

“It is time for the government to recognise the human rights violations associated with the use of the death penalty and embark on a journey towards its full abolition.”

‘Finally, I have won full and complete victory’

Now 88, Hakamada’s long incarceration has taken a toll on his mental and physical health. After the Shizuoka district court declared him not guilty of the 1966 murders, he managed a few words for his supporters.

“Finally, I have won full and complete victory,” he said, with Hideko at his side encouraging him to speak. “I couldn’t wait any longer” for the verdict, he added. “Thank you very much.”

Japan, the only major industrialised country along with the US to retain the death penalty, has resisted years of international pressure to abolish the practice. More than 140 countries and regions had abolished or suspended capital punishment by the end of 2022, according to Amnesty International, while most US states have either abolished it or put it on pause.

Japan has been singled out for its “inhumane” approach to executions, in which inmates are told they will be taken to the gallows only an hour or two beforehand and offered the choice of a last meal. They are denied contact with their family and lawyers, who are informed only after the execution has been carried out.

Many typically spend years, and in some cases, decades, on death row with the threat of execution constantly looming – a state of limbo that, according to Hakamada’s supporters, ruined his mental health and plunged him into a “world of fantasy”.

In a 2009 report, Amnesty said death row inmates in Japan were being “driven insane” and exposed to “cruel, inhuman and degrading” treatment and called for an immediate halt to executions.

According to the justice ministry, 77 people have been executed in Japan since 2007, and another 107 remain on death row, 61 of whom have requested retrials.

In its ruling in Hakamada’s case – which came a decade after he was freed pending a retrial – the court issued a scathing attack on police officers who had fabricated key evidence that led to his conviction in 1968.

His initial confession to having robbed and murdered the president of a miso maker, his wife and their two teenage children had been obtained through “inhumane” interrogations and mental and physical torture, the ruling said.

But for the efforts of his lawyers and supporters, and support for his campaign overseas, Hakamada could have met the same fate as former members of the Aum Supreme Truth Doomsday cult arrested over the 1995 sarin gas attack on the Tokyo subway in which 13 people died and thousands of others fell ill. Ten of the executed 13 cult members were seeking retrials when they were hanged in 2018.

‘No justice system can be perfect’

Japan’s enthusiasm for carrying out the death penalty can depend on the beliefs of the justice minister, who must sign an execution order for executions to take place. No hangings took place in 2011, a de facto moratorium that was attributed to the then justice minister, Keiko Chiba, a sceptic who had earlier ordered a review of the death penalty.

Japan’s last execution was in July 2022, of Tomohiro Kato, who killed seven people in a frenzied knife attack in the Akihabara district of Tokyo in 2008.

But the prospects for a permanent end to executions are dim. This week Japan’s new justice minister, Hideki Makihara, said abolishing the death penalty would be “inappropriate” given the strength of public opinion.

Writing on the Oxford University law faculty blog after the Hakamada ruling, Saul Lehrfreund, co-executive director of the Death Penalty Project, said: “Rather than using public opinion as an excuse for retaining the death penalty, political leaders in Japan should exercise their judgment based on an informed and rationale appreciation of the case for abolition, recognising that no justice system can be perfect.

“The legacy of this appalling human tragedy must be a change in the government’s stance on the future of capital punishment.”