Unanswered questions

Li has also submitted a list of unanswered questions and anomalies to the Shandong court, such as his suspicions that Nie's testimony was obtained under duress. Chinese legal procedure requires that a suspect's first recorded testimony must be obtained within 48 hours of arrest, but Nie's wasn't recorded until several days after his arrest.

In addition, the records show that the testimony, containing 5,000 to 6,000 words, was made in just two hours, which Li believes would have been impossible for someone such as Nie, who had a bad stammer that became more pronounced under stress.

"An articulate person with a clear mind can barely utter 6,000 words in two hours, so how could Nie, a man with a bad stammer, who was locked up?" he asked.

"However, I was encouraged after the April forum with the lawyers and legal officials. The new regulations have prompted an even greater determination that justice must be done in every case," he said.

Since 2013, when President Xi Jinping proposed legal reforms that emphasize "law-based governance", China's top legal official, Zhou Qiang, has highlighted the importance of preventing miscarriages of justice.

Last year, 1,317 verdicts were overturned on appeal, including the high-profile case of Hugjiltu, from the Inner Mongolia autonomous region, who was executed 18 years ago after being convicted of rape and murder. His conviction was quashed in December and his family received State compensation. The officials and police involved in the case are now being investigated and could face prosecution if they are found to have acted improperly.

"Every judicial officer must deal with cases in the light of the facts and in accordance with the law. We feel guilty about these miscarriages of justice and we will learn from them. To prevent future tragedies of this kind, we will investigate every detail of every case," Zhou said in September.

As the December deadline draws closer, Zhang Huanzhi is determined to remain calm and optimistic. "I believe in my son's innocence, and I have faith in the judicial system. However, no matter what the result may be, I really hope no other family will ever have to suffer what we have been through," she said.

Contact the writers at luowangshu@chinadaily.com.cn and caoyin@chinadaily.com.cn