Chamba was born in 1961 in the Ecuadorian province of El Oro. Between 1988 and 1993 he killed young women in and around Machala, on the Pacific coast, raping them and strangling them with a ligature. The Ecuadorian press called him the Monster of Machala.
He was convicted in Ecuador in 1993 and sentenced to sixteen years, which was at that time the maximum term available under Ecuadorian law regardless of the number of victims. He served it in full and was released in 2004.
He then emigrated to Spain and found work in agriculture in the Valencian Community. Within months of his release he raped and killed a young woman there, and was arrested after DNA taken at the scene was matched to him. He was convicted at Valencia and sentenced to forty-five years on November 5, 2006. The victim is not named here because the Spanish reporting of her identity is inconsistent and no judgment is accessible.
The case became an argument in Spain about whether the criminal records of migrants were checked at all, and in Ecuador about the sixteen-year cap, which was raised afterwards. The count of nine is eight in Ecuador and one in Spain; the Ecuadorian convictions are the basis of the first figure and were not individually re-examined.