In 1995 the intermediate court in the city of Shijiazhuang sentenced Nie Shubin to death for the rape and murder a year earlier of Kang Juhua in a suburb of the northern Chinese city. As is normal in China, he was executed soon afterwards.
Then in 2005, Wang Shujin was arrested and confessed to four murders, including the one for which Mr Nie had been executed. However, Wang was convicted of only three murders, and a prosecutor has refused to accept Wang's confession to the fourth murder, saying details of the crime he provided do not match evidence at the crime scene.
The case has brought renewed attention to bear on the death penalty in China.
Wang, who is on death row, is now appealing his death sentence, and seeking leniency because his confession to the fourth murder would clear the name of Nie Shubin.
At the time he made his confession, Wang was not aware that Mr Nie had been convicted of the murder, and he did not know the executed man.
“It’s a huge irony,” said Peking University law professor He Weifang. “Wang is yelling about this other crime he has committed but the court says they only want him for certain other crimes. It falls on the real murderer to clear Nie’s name, which is such a shame.”
China keeps the number of people it executes secret but it is thought to impose the final sanction in thousands of cases every year.
While the death sentence is considered a useful deterrent, there is growing scepticism, fuelled by some high-profile unsafe convictions.
