Fifteen years ago my son Stephen was murdered. To lose one's child is a devastating blow from which a mother can never fully recover. And to lose one's child as a result of a violent attack - in the case of my son Stephen, a racist attack - leaves an even deeper wound. But it is the failure to get justice that stops that wound from ever truly healing.
Stephen was only 18 when his life was cut short on a south-east London street. Jiang Jielian was 17 when, on the night of 3 June 1989, he was shot through the heart by Chinese riot police on their way to Tiananmen Square in Beijing. Like Stephen, he was left to bleed to death. He was one of the first to be killed when troops "cleared" the pro-democracy protests.
Like me, his mother Ding Zilin wanted to know why her son had been murdered and who had taken the life of an unarmed teenager; and she wanted justice. In August 1989, she met another bereaved mother, Zhang Xianling. Others joined, and the group became the Tiananmen Mothers.
Ever since the 1989 crackdown, public mourning in the weeks before the anniversary has been strictly forbidden. The Tiananmen Mothers have tried to mourn their children in graveyards and nearby areas on that day, but time and again they have been stopped.
Many of the Tiananmen Mothers have been arrested, harassed and persecuted. In 1991, Ding Zilin was forced into early retirement from her job at Peking University and her Communist Party membership was revoked. In 2004, she and other Tiananmen Mothers were put under house arrest shortly before the 15th anniversary of the crackdown to prevent them from holding any public memorial. The authorities have even frozen cash donations from overseas sent in support of the victims' families.
Last year the authorities seemed to relax the controls. Ding Zilin, her husband and two other members of victims' families were allowed to light candles in front of pictures of their children in a short remembrance ceremony on Chang'an Avenue, west of Tiananmen Square, at the spot where Jiang Jielian was killed. Around 20 of the Tiananmen Mothers were also able to hold a meeting in Beijing. They shared their grievances and feelings, and mourned together. This was the first time they had been allowed to organise such a meeting prior to the anniversary. Since then, however, the repression has intensified and references to 4 June 1989 have been stamped out by the government.
An official report issued by the Chinese authorities at the end of June 1989 claimed that "more than 3,000 civilians were wounded and over 200, including 36 college students, died during the riot". The exact figures are unknown, but Amnesty believes that many more were killed in Beijing in 1989. Tens of thousands of people were arrested throughout China in the aftermath of Tiananmen Square.
Many were tortured. Some were executed. Others were sentenced to long jail terms after unfair trials. Amnesty believes that dozens are still imprisoned today.
The British courts failed to bring anyone to justice for the murder of my son. The failings of the investigation were exposed in the Macpherson report. Some of the reforms that followed might help another mother get justice for the murder of her child, although it's of little consolation to our family. But the Stephen Lawrence Centre in Deptford, south-east London, stands as a monument to Stephen and the promise that might have been fulfilled if he had been allowed to live.
Ding Zilin and the other Tiananmen Mothers have no such monument. Chances are they will again be placed under house arrest to stop them commemorating their children's deaths. They should be allowed to mourn. And they should be allowed to find out exactly what happened in June 1989 and to debate it in public. Until that time, the wounds of Tiananmen Square will never be able to heal.
To show your support for the Tiananmen Mothers go to www.amnesty.org.uk/china – or join Amnesty’s demo outside the Chinese embassy, Portland Place, London W1, at 6pm on 4 June