The small flat in Beijing almost vibrates with a mother's anger. "In my eyes, my son did not die accidentally. He died in a massacre. Its inhuman atrocity, its violence will not change, not ever. By any international standards, a nation's army killing peacefully demonstrating students is a massacre."
The words are those of Ding Zilin, a 70-year-old professor, speaking of the night two decades ago when the all-powerful authorities in China were so rattled by student protests that they brought their boot down with a lethal finality on the lives of many of those who had the temerity to question them.
On 4 June, it will be 20 years since the brutal quelling of student-led pro-democracy demonstrations in Tiananmen Square, Beijing, but which also flared up in many other cities. On the night of 3 June 1989, the People's Liberation Army moved in, killing hundreds and possibly thousands of people. China has never given a full account of what happened during the crackdown or who died. But Ding Zilin, can; and she does – for the sake of her son's memory, herself, and others like her.
Her 17-year-old son, Jiang Jielian, was one of the first to be killed when the tanks rolled in to crush the protests. Despite the curfew, Jielian had left the family home, but then, on the way to Tiananmen Square, he was shot through the heart by riot police. Eyewitnesses said her son was left to bleed to death, but was eventually taken to the Beijing Children's Hospital. He died before he could be brought inside.
The professor was born in Shanghai and taught philosophy at Renmin University in Beijing. Her husband, Jiang Peikun, was also at the university where he headed its aesthetics institute.
She told me last week: "This is the topic I'm most reluctant to talk about. I cannot bring my son back. It is so painful. It has been 20 years since 1989. Even today I think the June 4th Movement in 1989 was a tragedy, a result of a dictatorial system, thousands of years of feudal dynasties and 40 years of the Chinese Communist Party's centralised autocracy," she said. "From Mao Zedong to Deng Xiaoping, their domination is the continuation of 1,000-year feudal dynasties."
It was a massacre that changed the way the world viewed China. The image of a lone protester, still an anonymous figure, lying down in front of a tank at the edge of the square crystallised the hope and futility of the movement. However, within a few months, the lure of China's economic growth outweighed Western countries' moral qualms about dealing with the Communist government, and it was back to business as usual, a state of affairs that continues until today. However, the democracy movement spread internationally, and within months the Berlin Wall was down, Central Europe had shaken off the shackles of oppression, and governments in Warsaw Pact countries like Czechoslovakia and Poland did not opt to shoot on their own citizenry, and the world was changed.
These changes came too late for Jiang Jielian and his mother. After her son's death, Ding Zilin attempted suicide on several occasions. Then she became energised by her own suffering and anger.
Three months after the massacre, she came across a family that had suffered a similar loss. They soon began to talk to other mothers who had lost children. There was not a "hooligan" – as Chinese officials called the protesters – among the 150 families they eventually came into contact with. The group became known as the Tiananmen Mothers, and every year in early June they call on the government to answer for what happened to their children.
In the past few days, the Chinese government has defended the massacre, and ignored questions about a new memoir by former Communist Party leader Zhao Ziyang, who was ousted for opposing the crackdown. Foreign ministry spokesman Ma Zhaoxu restated the official view that the movement's crushing paved the way for China's economic success in the two decades that followed what he called "the political incident".
"Facts have proven that the socialist path with Chinese characteristics that we've pursued is in the fundamental interest of our people and it reflects the aspirations of the entire nation," said Ma Zhaoxu.
China's remarkable economic rise is cold comfort for the Tiananmen Mothers. "This massacre happened despite the concerns of the international community. Even though the Communist Party has tried to cover it up for 20 years, it is indeed a crime, and no power can change it. This crime demands justice," said Ding Zilin.
She doesn't want her child to be rehabilitated in the way that the Communist Party likes to do with once-disgraced leaders. "It is the Communist Party's trick and I do not buy it," she said. "Although nowadays some young people are selfish and ignorant, I do hope they will not suffer the same kind of fate, and their parents do not need to suffer this kind of pain. Only the people who have experienced such pain can tell what it's like," she said.
The Tiananmen Mothers group has three demands: "First and foremost, we want the truth. We are asking for an independent and fair investigation. The authorities should publish the name list of all victims of the 4 June crackdown, the total number of victims and the truth. They should give an account of every victim," she said.
"Second, the authorities should compensate those victims' families. And last but not least, accountability needs to be introduced. The people who bear the responsibility for this tragedy should pay according to laws. Our requests are quite different from the Communist Party's idea of 'rehabilitation', because we require that this issue should be handled by laws and justice," she said.
"Our loved ones have gone. This is a fact that we must accept. Nothing will change that. But as victims' families, we are asking for justice. As a Chinese mother, I hope this tragedy can never happen again in China, and that the powers-that-be cannot slaughter civilians in future. We want them to know that killers will be punished by laws. Deng Xiaoping ordered the army to shoot people, and that will remain in history forever."
She was nominated for the Nobel Peace Prize in 2003 for her efforts, and in 2006, Time magazine selected her as one of their 60 Asian heroes.
Over the years she has faced regular difficulties with the authorities for her activism. She has been effectively under house arrest for years, her Communist Party membership has been revoked, she has been under surveillance, and was forced into early retirement. She was ordered to leave Beijing during the 2008 Olympics. People who have lost the most important things in their lives don't care what happens to themselves, although this year has been particularly difficult for her, and she has come under serious pressure.
On 17 May, the families of the victims planned a memorial service for their loved ones, something they have done every five years since 1989. In 1999 it was at Ding Zilin's home.
"Every five years, the number of attendees has decreased. Now we are all old and sick people. We do not have much time left. And this year, several people have gone. I am not sure in 2014 how many people will still be living. But until we get justice, every year is the same to us," she said. The meeting was set for 2pm and Ding Zilin wrote the text to be read out.
Shortly before 10am, officials from the State Security Bureau came to her home. They said that, according to their information, some Tiananmen Mothers from Hong Kong, and possibly foreign journalists would join the group. "This would make for 50 people, which was quite large. They were telling lies. We did not inform any foreign journalists nor were any Hong Kong Tiananmen Mothers coming to the meeting. And the participant number was certainly less than 50. Only victim families would attend. Even in 1994, we only had 40 participants," she said.
However, the police did not allow her to attend. "From 10am until 1 pm they did not leave. They knew our ceremony would begin at 2pm. After some negotiation, they allowed me to mail my memorial article, which was necessary for this activity to take place. They even allowed other people to attend the ceremony – it was just me they didn't. They forbade me to go anywhere.
"I was very angry. Where are my human rights? Is China's human right situation improving? Five years ago, I could take part in the ceremony. But five years later, I cannot. They used false information and lies to restrict my personal freedom." As she said this, her voice trembled. "They killed my son and then they block the door. Why can I not attend the ceremony?"
She was not allowed to leave until the late evening, and even then four or five police officials followed her, asking her where she was going. "I said nothing. They were polite, said they were just obeying orders from higher authorities. But they were actually obeying evil orders. I told them to ask their superiors – Hu Jintao would be best – and say: 'Do you have children? If your children were dead, what would you do then?'
"My throat is sore ever since. I am still angry at what they have done to me. I'm sorry, I can't talk any more."