For twenty-seven years a woman in Nanjing went to the same office on the same day of every March and asked the same question. Has there been any progress.
She was asking about her daughter. The girl had been a medical student, and on 20 March 1992 she had gone to a classroom to study and never came back.
On the afternoon of 24 March 1992, in Nanjing, police lifted the cover of an inspection well beside a teaching building at the Nanjing Medical College. The student who had been missing for four days was inside it.
Her family name was Lin. She was twenty-two, in her fourth year. On the Friday evening before she disappeared she had told her roommates she was going to the classrooms with her bag and an umbrella, and she left the dormitory for the last time.
For the next twenty-eight years this was one of the longest unsolved murder cases in the city. It is also one of the clearest examples in Chinese true crime of a case that was not solved by better police work but by a change in what evidence can be made to say.
One. Friday, 20 March 1992
At about half past six that evening the student left her dormitory to study. She first sat in Room 268, found it draughty, and moved to Room 111, where she settled in alone.
A classmate remembered seeing her there on the way out. She never got back to her room.
At around ten that night, according to the findings the court later made, a man approached her. He tried to strike up a conversation and she refused him. He then threatened her with an iron bar and forced her into the courtyard inside the building, where he raped her. She fought, and he struck her head with the bar, repeatedly.
Afterwards he dragged her to an inspection well under a window on the north side of the building, put her into it head first, and replaced the lid. He threw her bag, her books and her clothes into a second well nearby.
The forensic finding was that blunt force to the head had caused severe brain injury, and that she had drowned.
That same night, two members of the college security patrol were walking the building. In a washroom they came across a man who struck them as wrong. Square-faced, dark-skinned, a few spots on his left cheek, about five foot seven, twenty-six or twenty-seven years old, standing at the basin wiping his face with a handkerchief.
One of the guards spoke to him. The man ran, climbed a wall and vanished.
That was the only likeness the killer ever left behind, and for the next twenty-eight years it was the most concrete thing the police had.
Two. Fifteen thousand people
The case shook Nanjing. It was one of the very few Chinese criminal cases of that severity in the city at the time, and it was followed nationally.
The Nanjing public security bureau pulled several hundred officers from other duties into a task force. For months they walked and knocked and asked. They checked several thousand leads and interviewed more than fifteen thousand people. They offered a reward of ten thousand yuan for information.
In 1992 that was a great deal of money.
It made no difference.
There was also nothing at the scene that the science of 1992 could have used. Police work in China then meant no cameras, no location data from phones, no mass data analysis. What the task force could do was take the guards’ description, draw it, and knock on doors, bringing in one suspect after another to check age, face and movements. The drawing, with its square face and its spots on the left cheek, was copied and pasted up on police station walls and school gates, and it faded there year after year.
It was not for want of effort. Their tools simply could not reach a man who would not come into view for another twenty-eight years.
China then had no national fingerprint database and no national DNA database. The biological material taken from the victim was carefully preserved, numbered, and put into an evidence room. It was a letter with an address on it but no street, and it sat there for more than twenty years.
The file went quiet. The student’s classmates graduated, found work, married. And the man who killed her went on living in the same city.
Only one person did not stop.
The girl’s mother went to the police every year on 24 March, the day her daughter’s body was found, and asked how the case was going.
Once a year. For twenty-seven years.
Then, in June 2018, the Nanjing police set up a unit devoted solely to the oldest unsolved killings in the city, and put this one at the head of its list. Units like it work on a simple premise. Forensic science keeps moving, and what was impossible twenty years ago may be routine today. Old cases are not forgotten. They are queued.
Three. The road that was not open yet
There is an English parallel that makes this part easier to see. In 2018, in California, police arrested the man known as the Golden State Killer, decades after a series of rapes and murders across the state. They did not find him by following him. They found him by uploading a crime-scene DNA profile to a genealogy website where people look for their cousins, building a family tree out of distant relatives, and working down the branches until one name was left.
The same idea was waiting in Nanjing. Both cases turned on the same fact: a killer’s DNA is not only his own. It is partly his fathers, his brothers and his cousins, and that can be enough to find him.
Four. 2020: the unexpected break
The turn came in early 2020, from a place that had nothing to do with the case.
That winter, as epidemic screening spread across the country, police in Peixian county, in Xuzhou, Jiangsu province, stopped a man surnamed Ma during a routine check. He gave a DNA sample, and it went into the system.
In February 2020 the forensic centre of the Nanjing police got in touch with the DNA laboratory of the Peixian criminal investigation unit, and the answer that came back was one nobody had expected in 1992. The DNA of the killer, taken from the victim, matched that of the man from Peixian closely.
On 19 February 2020, Nanjing police concluded that the Ma family of Peixian contained the man they were looking for.
Two days later, on 21 February, the laboratory in Peixian compared the DNA from the material taken from the student in 1992 with the DNA of that Ma relative, using markers on the Y chromosome. The two matched closely.
One technical point matters here. The Y chromosome passes down the male line almost unchanged, so every man in the same paternal family carries nearly the same one. A match therefore does not mean that this particular man was the killer. It means that the killer was a man of this family.
The police followed the line down. They collected mouth swabs from eleven men of the Ma family who were living locally and were the right age. They tested all eleven. All eleven were excluded.
The trail was about to go cold again.
Then a detail that had been sitting in the file, unremarkable, came up. One member of that large family had gone to Nanjing as a soldier decades earlier, and had settled there, and had lived in the city for more than fifty years.
He had a son in Nanjing.
The son’s age fitted the description the campus guards had written down in 1992: twenty-six or twenty-seven.
Five. Six in the morning
In the small hours of 23 February 2020, the Nanjing laboratory reported that a man living in the Xuanwu district of the city, Ma Jigang, matched the killer exactly.
At about six that morning, police knocked on his door and took him away.
Ma Jigang had been born in October 1966, in Peixian county, Xuzhou. In 1992 he was twenty-six. He worked as a driver for a large state-owned trading company, the Jiangsu Sumec Group, driving for its executives, and he held a partnership in another firm.
To the people around him he was a mild man. Colleagues and neighbours described someone who never raised his voice, who kept dogs, who would look after a neighbour’s dog when the neighbour was away. When word went round that he had been arrested, many of them said they simply could not believe it.
Look further back and there is one more line in the record. He had a previous conviction for theft. He had served the sentence and come out, and then he committed this.
In all those years he never left Nanjing. He drove the company cars, went home, kept his dogs. He looked like millions of other middle-aged men in the city. The teaching building was still standing and the college was still there, in the same city, and not once did anyone connect him to what had happened inside it.
Six. Can you still prosecute, twenty-eight years later
He was caught. The case was not over. It hit a wall that has no exact English equivalent, and it is worth slowing down for.
Under Chinese criminal law, where the maximum penalty for an offence is life imprisonment or death, the case can no longer be prosecuted after twenty years. From 1992 to 2020 is twenty-eight.
The law leaves one door open. If, after twenty years, prosecution is still considered necessary, the case may be brought only with the approval of the Supreme People’s Procuratorate.
The Nanjing municipal procuratorate set up a team two hours after Ma Jigang was detained and moved in early to guide the investigation. Its lawyers had to answer two questions. Should this be prosecuted at all, and, after twenty-eight years, would the evidence stand up.
The second question was as hard as the first. Much of the material was handwritten, and blurred by age. The team transcribed and reviewed every document, producing hundreds of thousands of characters of reading notes and opinions in a short space of time, and returned five categories and twenty-five specific follow-up demands to the police.
And the DNA itself? How was it extracted in 1992, how was it stored, was it ever contaminated? The team went to the forensic centre of the Nanjing police, checked the chain of custody step by step, read the raw traces of every DNA test done over the decades, and interviewed the pathologists who had attended the autopsy in 1992.
Their conclusion was that the testing was genuine and valid.
On 8 May 2020 the Supreme People’s Procuratorate approved the prosecution. The reasoning was blunt. Ma Jigang was suspected of intentional homicide and rape, both carrying a maximum penalty of death. The nature, circumstances and consequences of the offences were exceptionally serious; the passage of twenty years had not removed the harm he had caused or the public impact of the case; and the law required that he be prosecuted.
Seven. The sentence
The Nanjing Intermediate People’s Court heard the case in closed session on 16 September 2020.
On 14 October 2020 the court sentenced Ma Jigang in public. For intentional homicide, death, with deprivation of political rights for life. For rape, seven years in prison. The sentences were combined and the death penalty was to be carried out, with deprivation of political rights for life. The court also upheld the civil claim brought by the mother of the dead student.
Ma Jigang appealed. On 19 January 2021 the Jiangsu Higher People’s Court dismissed the appeal and upheld the sentence, and sent the file to the Supreme People’s Court for approval.
That review found the crime exceptionally grave. He had raped a university student late at night on a university campus, struck her head with an iron bar to overcome her resistance, and then, afraid of being found out, put her into an inspection well and covered it, causing her death. The court noted that he had served a prison term for theft and had offended again after release, and that his criminality and his danger to the public were serious. He was to be punished accordingly, with the two offences combined.
On 10 June 2021, acting on the order issued by the Supreme People’s Court, the Nanjing Intermediate People’s Court executed Ma Jigang. He was allowed to see close relatives beforehand. Prosecutors attended the execution to observe.
Between the evening the student walked into Room 111 and the morning Ma Jigang was taken from his home, twenty-seven years and eleven months went by.
In those years, forensic science changed twice over. In 1992 the police had interviews, a sketch and shoe leather. In 2020 a man who had never appeared on any list of suspects was lifted out of a population by a stretch of DNA he had inherited from his father.
And in those years a mother asked. She never got her daughter back. She did get that one day.
The detectives who worked the case in the beginning said afterwards, in an interview, that they would not close it until it was solved.
Everyone in the file finished their own stretch of the road. The college changed its name and became Nanjing Medical University. The well beside the building left no trace. The two campus guards, if they are alive, are very old.
And the mother went to the police every 24 March and asked. The last time she had to was in 2019, and that was the twenty-seventh time.
The next year, she did not have to go.
