The United States sent fifteen counter-insurgent specialists to El Salvador in March 1981 to train the newly formed battalion.[6] Weapons, ground vehicles, and helicopters were sent to the battalion which numbered around 2,000 soldiers.[6]
The battalion was disbanded in 1992 under the terms of the Chapultepec Peace Accords that ended the twelve-year civil war.[7]
Investigation by the Truth Commission for El Salvador
In the early 1990s, the Truth Commission for El Salvador was established by the United Nations to investigate war crimes committed during the civil war.[8] The report concluded that the battalion was responsible for the El Mozote massacre, the El Calabozo massacre, and the 1989 murder of six Jesuit priests.[9][10][11][12] The Battalion was also implicated in the killing of around 50 civilians on the banks of the Guaslinga river.[13]Human Rights Watch independently linked the battalion to additional massacres not cited in the UNTC report including dozens of people killed in Tenancingo and Copapayo in 1983, sixty-eight people killed in Los Llanitos, and three separate killings of civilians in 1989.[14]