Students from Nanjing International School have a class with students in northern Jiangsu province.

When they heard about the murder, relatives and friends of the Pfrang family thought it was an April Fools' Day joke. In less than a week, they would see the four murderers, aged 18 to 21, in court, wearing countrified clothes, poorly educated and jobless.

All four men came from the then poverty-stricken Shuyang county in northern Jiangsu province. One had worked as a cook for a short time. Another one once cut keys for a living.

The four defendants confessed in court that after being found by the Pfrang family, they panicked when hearing an incomprehensible language - and then committed the crime.

At that time, some Chinese media reported that Petra's parents wrote to the local judge, asking him not to sentence the four young men to death. Julia Guesten, a friend of the Pfrang family, told media that Petra's parents had sent a lawyer to China, and that the German state department had asked them to sign the letter to the court. Although their request didn't change the verdict, the story touched many Chinese readers.

Guesten was also one of founders of the Pfrang Association, which was established in November 2000 to help poor students in northern Jiangsu province to receive education, so as to break the tragic cycle of poverty, lack of education and crime.

"It's the best way to remember the Pfrang family," says Kristel Snoey, president of the Pfrang Association, who came to China from the Netherlands last July with her husband and two daughters.