BEIJING (AP) — When authorities in an eastern city announced that a BMW driver involved in a crash that killed two people was suffering from "acute transient psychotic disorder," Chinese online jeered so loudly that it aroused Communist Party concerns about a public trust crisis.

Some initial missteps by police in Nanjing already had undermined public confidence, and many people believed the diagnosis announced this week was just a creative way to gloss over the crime of a privileged person.

It turns out that the culprit has no apparent elite connections, and the medical diagnosis — which can limit criminal culpability — could be legitimate. Yet many Chinese responded online with a level of sarcasm that highlights their strong doubts that their government will adjudicate fairly, especially in cases where money might play a role.

"My advice for motorists and pedestrians alike is to watch out not only for cargo trucks but also luxury cars, because their drivers might be suffering from 'acute transient psychotic disorder' as ruled by so-called 'authorities' or 'experts,'" college professor Sun Daojin wrote on his microblog. "If you ever crash with them, they'll be fine, but you'll be completely done for."

Well-known commentator Shi Shusi changed his online profile picture to a mock certificate declaring himself as someone with acute transient psychotic disorder. "The BMW case in itself is a non-issue, but the hoopla around it shows the serious deficit China's public power has in terms of credibility, which is scarier than fiscal deficits," Shi said.

The widespread distrust unnerved the ruling Communist Party. The party's main newspaper, the People's Daily, called the case a "public trust crisis" and urged the Nanjing government to be transparent and release as many details as possible to regain the public's confidence.

"The public opinion has so stubbornly questioned the medical opinion because of the worry about black-box operations, which damage social fairness and erode legal justice," the newspaper wrote.

For many decades, the Chinese public tended to trust their authoritarian government, but that has unraveled with the opening up of society and freer flow of information over the past three decades. Still, the party-led government has clung to a system of shutting the public out of decision-making, leaving many skeptical and cynical to the point of rejecting anything the government says.

A steady stream of corruption scandals and incidents such as last month's Tianjin warehouse explosions that killed 165 people reinforce the public perception that their government is too corrupt to be trusted.

Police mistakes haven't helped.

In 2009, members of the Chinese public coined the phrase "70 kilometers" to describe irresponsible government acts after police in the eastern city of Hangzhou declared a speeding car was going only 70 kilometers (43 miles) per hour when it fatally knocked over a pedestrian. Police later apologized, and the offending car was ruled to have gone as fast as 100 kilometers (62 miles) per hour.

In Nanjing, police found themselves almost immediately on the defensive when details surfaced that the BMW sped through red lights at an intersection and crashed into three vehicles, including a bus, in June. Surveillance videos show flying shreds from a car that instantly fell apart, and media reports said two people were thrown out of the vehicle and died.

Police drew public scorn with an initial assessment that the BMW was going only somewhat faster than other cars. Later police calculations showed the BMW was speeding at 195.2 kilometers (121 miles) per hour. There was more online second-guessing about whether the man arrested, 35-year-old Wang Jijin, was a scapegoat; police later announced that DNA testing verified Wang was the driver.

Police said Wang was not under the influence of alcohol or illicit drugs, drawing more skepticism given reports that he had behaved irrationally following the collisions. Online commenters sneered at a police statement that the powder-like material found inside Wang's car wasn't drugs, but corn starch.

Three months later, Nanjing authorities offered an explanation: Wang was suffering from acute transient psychotic disorder at the time of the crash. Citing the medical condition implies authorities believe Wang may have been incapable of controlling himself.

Some members of the public immediately assumed the term — heard by many for the first time — was a convenient excuse to help reduce criminal liability, and they theorized that Wang must come from a privileged family that exerted influence over police.

Wang later turned out to be an ordinary businessman from a rural family who had moved to city to make a living by selling construction materials.

Wang has been arrested on a charge of causing a vehicular incident, a charge that assumes negligence. If he were deemed to have deliberately run the red light at a high speed, he could face the more severe charge of using dangerous methods to harm public safety, which is punishable by life imprisonment or death.

Tang Yinghong, a psychologist, wrote in an editorial in Beijing News that the public would naturally be skeptical when it is used to hearing scandals involving fake forensic evaluations.

"In a time when the government credibility is lacking, more details must be revealed to persuade the public to accept forensic evaluations that may appear counter-intuitive, such as who the experts were, what the supporting evidence was, and what kind of logic was used," Tang wrote. "You must show it before you can convince the public."