By Jan Rocha
BBC correspondent in Sao Paulo
The trial has begun in the Brazilian city of Belem of five members of a satanic sect accused of sexually mutilating and murdering young boys in Altamira, a town in the Amazon.
All the boys came from poor families
One of the five, Valentina Andrade, is the leader of an occult sect based in Argentina and two are doctors.
The crimes were practised over 10 years ago, but only now are the accused being brought to trial.
Between 1989 and 1992, the Amazon town of Altamira suffered a reign of terror, as one after another, 19 boys aged between eight and 14 were abducted.
They all came from poor families and were seized as they herded cattle, picked mangoes or were shining shoes.
Five managed to escape their captors. Six were found dead, with their sexual organs removed. Three had been mutilated, but managed to survive and five have never been found.
Incompetent police investigations and the delaying tactics of those accused, who were well known and influential in Altamira, mean that it has taken 11 years to bring them to trial.
Two are doctors, one is an ex-policeman, one a businessman and the leader of the group is a woman clairvoyant, Ms Andrade, the chief of a pagan sect based in Argentina.
It is believed the boys were mutilated so their sexual organs could be used in rites of black magic.
If the accused are found guilty they could receive sentences of up to 100 years.
The trial will last for at least a week.