A judge has given a prison sentence to a fourth Texas man federal officials say was linked to a gun used in a U.S. agent's death in Mexico. Otilio Osorio was sentenced Monday to seven years in prison after pleading guilty to conspiracy and other charges relating to a gun-running network. His brother, Ranferi Osorio, received a 10-year prison term for running the network. The firearms charges are not directly related to last year's death of U.S. Immigration and Customs Enforcement agent Jaime Zapata in Mexico. However, federal officials have said that another gun purchased in October 2010 by Otilio Osorio was used in the February 2011 attack on two ICE agents as they drove on a highway near San Luis Potosi in Mexico, killing Zapata and wounding Victor Avila.