5. On November 9, 2006, the Commission received a petition lodged by the petitioners, the pertinent parts of which were transmitted to the State so that the State could lodge its response within a period of 60 days from February 5, 2007. On June 4, 2007 the State lodged its response to the petition. 6. The petitioners provided the IACHR with additional information on November 17, 2006, July 20, 2007, October 19, 2007, and March 5, 2008. These communications were duly transmitted to the State. 7. Furthermore, the IACHR received information from the State on August 29, 2007, and on January 3, 2008. These communications were duly transmitted to the petitioners. III. A. POSITIONS OF THE PARTIES Petitioners 8. The petitioners allege that Gabriel Sales Pimenta was a lawyer with the Marabá Rural Workers Union (Sindicato dos Trabalhadores Rurais de Marabá, hereinafter “the Union”), in the State of Pará. They report that the alleged victim played an important role representing the rural workers in the State in that he had succeeded in bringing a judicial action called a mandado de seguranca which nullified the effects of a precautionary measure granted by the judge of first instance in possession restitution proceedings which had lead to the eviction of 158 families from lands in the region known as Pau Seco, in the municipality of Marabá. As a result of the actions undertaken by the alleged victim, the 158 families returned to the lands in Pau Seco. 9. They claim that the alleged victim then started to receive threats from ranchers Manoel Cardoso Neto and José Pereira da Nóbrega and was told that he should cease working on behalf of the workers. The petitioners claim that it was common knowledge that Mr. Manoel Cardoso Neto had threatened to kill Gabriel Sales Pimenta and had even specified that he would do so before August 4, 1982 (the date when there was due to be a judicial hearing concerning the ownership of the Pau Seco land.) 10. The petitioners claim that on July 18, 1982, Gabriel Sales Pimenta went to a meeting of the political party to which he belonged and from there to a restaurant, and was murdered while leaving the restaurant in Marabá by gunshots at point blank range in the street. They state that the crime was committed in the presence of two of the alleged victim’s friends, Edson Rodríguez Guimarães and Neuzila Cerqueira Guimarães, by a person who did not cover his face, and was obviously intent on intimidating them and demonstrating his own power. 11. The petitioners state that a police investigation (Inquérito Policial) was set up IPL No. 024/82 to look into the crime. Furthermore, this investigation collected the following evidence: statements from the suspects (Manoel Cardoso Neto, José Pereira da Nóbrega and Crescencio Oliveira de Sousa); a post mortem report dated July 20, 1982; a search of the house of Manoel Cardoso Neto; a ballistic report on the weapons dated July 21, 1982 (one seized in the house of Manoel Cardoso Neto and the other belonging to José Pereira da Nóbrega); an investigation into the purchase, by Manoel Cardoso Neto, of a vehicle similar to the one used by the murderer; and an expert technical report. 12. The petitioners state that on the basis of the evidence, the police concluded on July 22, 1982 that Manoel Cardoso Neto and José Pereira da Nóbrega were the intellectual authors of the murder. Subsequently, on September 8, 1982,