With the negotiated cease-fire agreement signed on January 16, 1992, in Mexico City, the twelve-year-old conflict in El Salvador has formally come to an end. The agreements under United Nations supervision between the Salvadoran government and the Farabundo Martí National Liberation Front (FMLN) envision unprecedented reforms: to reduce the military, dissolve the elite, immediate-reaction battalions, eliminate two of the security forces, create a new National Civil Police, and demobilize the FMLN and fully integrate ex-guerrillas into civilian life. These transformations hold forth the greatest possibility yet for the respect for human rights and the achievement of social justice in El Salvador. In order to further the prospects for accountability, this report examines one of the most egregious massacres of the entire conflict: the cold-blooded murder of hundreds of civilians in northern Morazán by Salvadoran troops of the U.S.-trained Atlacatl Battalion in December 1981. The massacre at El Mozote, probably the largest mass killing reported during the war, was a formative experience for most of the thousands of peasants and many of the guerrillas in northern Morazán. It and similar Army operations in Morazán sent thousands of peasants fleeing across the border into exile in Honduras, and helped fuel the growth of the guerrilla movement.