Zhang was the head of a gang of muggers who threatened their victims with knives in 14 attacks over three months in Peking. But Mr Sheng admitted "there were no severe injuries or deaths in the robberies" and the total haul was just over pounds 100.
At a recent rally in Pinggu County, Zhang, nevertheless, was sentenced to death. "The death penalty can apply to those malefactors who commit serious crimes, not only to those who cause somebody's death," said Mr Sheng.
China is in the grip of the national "Yan Da" (Strike Hard) campaign against crime, launched at the end of April. Since then, tens of thousands of people have been arrested and, according to Amnesty International, there have been more than 700 executions - a total which is likely to be an underestimate.
"Strike Hard" has received saturation coverage in the media, with alleged criminals paraded in public against details of horrific crimes. According to Mr Sheng, between 3 May and 10 June, the courts held 56 public sentencing rallies in Peking, attended by 200,000 people. The campaign has widespread public support. Ordinary Chinese are angry about the increase in crime and stunned by the savage murders, rapes and robberies now being publicised.
As the Chinese Communist Party prepares to celebrate its 75th anniversary on 1 July, an anti-crime blitz is popular. The last such campaign was in 1983, when the execution toll may have been 10,000.
But in a country where legal procedures are weighted against the accused, such crackdowns end in "production-line" justice, under which people are arrested, tried and even shot within days. In the first seven weeks, Mr Sheng said the Peking court dealt with 1,633 cases involving 2,495 criminals.
Even legal experts have spoken out against the wave of executions. Last week, three jurists signed a commentary in the Legal Daily newspaper. "Severe punishment should not be meted out if this violates the law," they wrote.
Death sentences have been imposed for minor offences. One report was of eight people sentenced to death for stealing cows. Others have been shot for counterfeiting money. Six people were executed for stealing railway equipment and four people in Changchun city were executed for stealing cars.
Arlette Laduguie, at Amnesty, said "Strike Hard" appeared to be using 1983 legislation, which provided for summary trials even for people facing the death penalty. Some 68 offences in China warrant the death sentence. "Defendants have no warning of their trials in advance, so cannot arrange a lawyer. They have no copy of the indictment," she said.
Police claims of astonishing success rates since the start of "Strike Hard" lack credibility. In the same way that national campaigns to improve the Chinese harvest always yield record crop figures, the provinces are doing their best to outdo each other in the war against crime.
Authorities in the south-eastern province of Guangdong said they had "cracked" 3,850 crimes and "smashed" 843 criminal gangs in just two days last month. In Guangxi province, police in 10 days claimed to have uncovered 2,297 criminal cases, crushed 158 criminal gangs and detained 5,940 suspects. In a three-day blitz in Shanghai, 1,500 people were arrested.
However, many people are being arrested for old, previously unsolved crimes. And others, already in prison, presumably on suspended death sentences, are just being taken out of jail and shot.