5 21. On April 30, 1999, Jorge Reyes Zapata submitted a brief, signed by himself and by Sergio García Valdés, Vicente Torres Irarrázabal, Francisco Javier Donoso Barriga, Matías Pérez Cruz, Cristian Heerwagen Guzmán and Joel González Castillo, asking to be heard by the Inter-American Court in the capacity of amici curiae. Moreover, they requested to be heard “in all the oral and written instances that the rules of procedures allow.” On June 1, 1999, on the instructions of the President, the Secretariat informed Mr. Reyes Zapata that “until the reparations stage, the possibility of participating in the proceedings before [the] Court was restricted to the parties to the respective case, that is, to the Inter-American Commission for Human Rights and the respondent State” and, consequently, it was not possible to accede to their request to be heard as collaborating third parties. 22. On May 25, 1999, the Commission submitted its observations on the State's brief of April 26, 1999. 23. On May 27, 1999, the State appointed Edmundo Vargas Carreño, Chilean Ambassador to Costa Rica, as its agent and indicated that it would receive notifications at the Chilean Embassy in Costa Rica. 24. On September 2, 1999, the State submitted its answer to the application. 25. On October 12, 1999, the Commission submitted a brief in which it stated that the answer to the application submitted by Chile was “manifestly time-barred” and requested the Court to reject it and to abstain from considering it when examining the case. 26. On October 25, 1999, the Commission submitted the final list of witnesses and expert witnesses offered in its application and requested the Court to substitute the expert witness, Lucas Sierra Iribarren, with the expert witness, Juan Agustín Figueroa Yávar. On October 26, 1999, on the instructions of the President, the Secretariat granted the State until November 1, 1999, to submit its observations on the substitution requested by the Commission. 27. On October 26, 1999, the President issued an order in which he convened the Commission and the State to a public hearing to be held at the seat of the Court at 10 a.m. on November 18, 1999, and summoned to the hearing the witnesses, Ciro Colombara López, Matías Insunza Tagle and Alex Muñoz Wilson, alleged victims in the case, and also the expert witnesses, Humberto Nogueira Alcalá, José Zalaquett Daher and Jorge Ovalle Quiroz, all of them proposed by the Commission in its application. In the same order, the parties were notified that they could present their final oral arguments on the merits of the case immediately after the evidence had been received. 28. The State did not submit observations on the substitution of the expert witness named by the Commission within the period granted to it. On November 6, 1999, the President issued an order convening Juan Agustín Figueroa Yávar to appear before the Court to give an expert report. 29. On November 8, 1999, Chile submitted a brief indicating that it had no objection to Juan Agustín Figueroa Yávar appearing before the Court. It also requested the Court to convene José Luis Cea Egaña and Francisco Cumplido, the persons it had proposed in its answer to the application, to give an expert report in the public hearing on the merits of the case.