By Julia Harte and R. Jeffrey Smith / Center for Public Integrity

Carlos Alberto Ospina Ovalle was deep in the Colombian mountains in the autumn of 1997, directing an Army brigade in a major offensive against a group that Washington formally designated that year as terrorists, the Revolutionary Armed Forces of Colombia, or FARC. He achieved some battlefield successes, and five years later, he was appointed chief of the Colombian armed forces.

Flash forward to this month: Ospina was in a military classroom in Washington, lecturing at the National Defense University to an elite group of U.S. and foreign military officers and civilians from a podium set before a row of Latin American flags. Colleagues at the school, which is chartered by the Joint Chiefs of Staff, say Ospina is particularly respected there for his experience under fire and his deep knowledge of counterterrorism strategy.

In recent weeks, however, a less heroic portrayal of Ospina’s past has caught up with him, provoking controversy over his presence in the United States among lawmakers on Capitol Hill and within the Obama administration, and new expressions of concern from Washington’s passionate community of Latin American specialists.

The controversy concerns allegations that back in 1997, Ospina’s Fourth Brigade allowed a pro-government militia to sack the village of El Aro in northern Colombia, brutally killing several people, including children, and leaving others missing. One shopkeeper was tied to a tree and had his eyes gouged out and his tongue removed, according to witness reports at the time cited by human rights investigators. Dozens of homes were destroyed, and more than a thousand cattle were stolen.

The controversy also concerns whether the National Defense University, the nation’s premier joint military educational institution, adequately vets its hires from foreign forces for potential involvement in human rights abuses. State Department officials have privately protested its apparent lack of diligence, and the Pentagon may soon be changing its procedures, according to multiple government sources.

“Reports that NDU hired foreign military officers with histories of involvement in human rights abuses, including torture and extra-judicial killings of civilians, are stunning, and they are repulsive,” said Sen. Patrick Leahy (D-VT) in a statement to the Center for Public Integrity. Leahy is the author of the “Leahy Law” prohibiting U.S. assistance to military units and members of foreign security forces that violate human rights.

“I have sought, and have yet to receive, an explanation from the Defense Department,” said Leahy, whose aides began discussing NDU’s hiring of Ospina and several other foreign military officers with Obama administration officials after inquiries by the Center for Public Integrity. “We need to know whether any such individuals remain at NDU or in the United States, and what guidance is in place to ensure that this does not happen again.”

A spokesman for the Pentagon, Lt. Col. Joe Sowers, said he could not comment immediately for this story but said officials in the Department of Defense were preparing a response.

The NDU’s Center for Hemispheric Defense Studies, where Ospina taught from 2006 to 2014 before moving to another academic center at the university’s campus in Washington, D.C., has itself been rocked by controversy in recent years. A nonpublic report in 2012 by a U.S. Army colonel, appointed by the center’s director in response to persistent staff complaints, concluded that “a hostile work environment exists”; that its staff had displayed “a lack of sensitivity towards the use of derogatory language”; and many employees felt its leaders routinely retaliated against those who questioned them.

The report, obtained by CPI under the Freedom of Information Act, depicted a sort of frat-house atmosphere at the center. It stated that staff had exchanged “racially charged emails”—including one directed at President Obama; used offensive language such as “faggot,” “buttboy,” and “homo”; and that “women employees feel that they are treated inappropriately.” Even senior leaders used “inappropriate hand gestures,” it said, and mentioned simulations of masturbation.

Ospina, in a telephone call from his NDU office this week, said he decided late last year to retire from NDU when the semester ends in two months and return to Colombia because—he said—he misses it. He said accusations that the Fourth Brigade played any role in the El Aro massacre were false and that “we’ve been cleared.” He only found out about it, he said, after the carnage was over, from the head of a battalion under his command.

“The FARC wore the same uniforms as the army, so people would assume that they were the army,” he said. The region that his brigade of roughly 2,000 soldiers patrolled included 125 municipalities, and it was woefully underequipped, he said, so he usually did not have timely intelligence about what was happening in the region.

Colombia’s attorney general looked into the allegations about Ospina in 2001 and did not find proof of the army’s involvement in the El Aro events. But a report in 2006 by the Inter-American Commission on Human Rights, an investigative tribunal affiliated with the 35-nation Organization of American States, concluded that “the participation and acquiescence” of the Colombian army in the paramilitary actions at El Aro and the theft of livestock by “agents of the state” were demonstrated.

“There is no doubt,” said Adam Isacson, director of the regional security program at the Washington Office on Latin America, an advocacy group, that Ospina “did nothing to stop that massacre from happening.” Human Rights Watch and Amnesty International, in reports published in 2000 and 2001, respectively, cited extensive ties between paramilitaries involved in the El Aro massacre and the Fourth Brigade under Ospina’s command. “Among the cases in which Ospina is implicated” is the October 1997 event, the Amnesty report states.

Jim Zackrison, a former intelligence analyst with the U.S. Navy’s Office of Naval Intelligence and scholar at the NDU’s Institute for National Strategic Studies, said to the contrary that in his view, the Colombian had enormous charisma and “was the last guy you would find participating in a massacre.”

Zackrison said he invited Ospina to speak to his son’s Boy Scout troop and that the former Armed Forces commander regaled them with a story about “the time he took a bullet for the president” and an account of military strategy while the boys walked along the Gettysburg trail. Zackrison said he recalls Ospina telling a classroom of NDU students on another occasion that 90 percent of the time, confessions derived from torture will lead interrogators down false paths.

But human rights officials at the State Department consider the human rights groups’ allegations about Ospina’s involvement in the El Aro incident credible, according to multiple sources.

The department looked into Ospina’s record after inquiries were made by Leahy, a senior government official said, and has serious concerns about his hiring and the absence of appropriate NDU review beforehand. The official, who spoke on the condition he not be identified, said it seems “there are cases that slip through the cracks” because NDU is not “plugged into a daily conversation” about foreign policy and human rights.

Ospina is not the first NDU lecturer to be accused in recent years of involvement in serious human rights abuses.

A former brigadier in the Chilean army, Jaime Garcia Covarrubias, taught courses from 2001 until 2013 on security strategy and democratic leadership, according to NDU documents listing him as a professor in the William Perry Center for Hemispheric Defense Studies, named after the former U.S. defense secretary. The center is considered a teaching arm of the U.S. Southern Command.

An NDU promotional video from October 2011 shows Garcia Covarrubias standing before a group of students in a red bow tie and describes him as the teacher of a course in Advanced Civil-Political-Military Relations. Former colleagues described him as part of the school’s inner circle of administrators and faculty members, who held unusual sway over its policymaking.

Internal alarms were initially raised about Garcia Covarrubias by others at NDU in 2008 who cited published allegations that he worked for Chilean dictator Augusto Pinochet’s secret police at a base where prisoners were allegedly murdered. But the school’s administrators undertook no investigation of their own at the time, according to documents and interviews.

Garcia Covarrubias was hired “with the approval and full consultation of the U.S. Embassy in Santiago,” said Dennis Caffrey, who was dean of students and administration at the time. Caffrey said that to his knowledge, the claims swirling around Garcia Covarrubias are only unproven “accusations.”

Regional press reports in 2010 and 2013 said Garcia Covarrubias had been accused by prisoners and witnesses of beatings and torture. A former prisoner at Garcia Covarrubias’s regimental base in the southern city of Temuco, Herman Carrasco, told an appeals court there in September 2010 that Garcia Covarrubias “forced us to perform naked acts of sodomy, without success,” according to an article published that year by the Spanish news agency EFE.

Finally, in 2013, a Chilean judge indicted Garcia Covarrubias for first-degree murder in 1973 of seven political prisoners at his Temuco base and barred Garcia Covarrubias from leaving the country. The bodies of the prisoners had been thrown into a river, and Garcia Covarrubias and his colleagues at the base told others they were killed while trying to attack the guards, according to a news report on his indictment by the Chilean newspaper Cooperativa.

At the time of the killings, Washington was tightly allied with the Chilean government. A diplomatic cable several days later to the secretary of state by a senior U.S. diplomat, Jack B. Kubisch, mentioned the deaths of “seven leftists…on a military post in a Southern city” as a failed “leftist initiative.” Kubisch served as NDU’s vice president from 1977 to 1979 and on an advisory board to its Board of Visitors in 1982, according to a university spokesman. He died in 2007.

A 2013 travel prohibition from a Chilean judge blocked Garcia Covarrubias’s return to NDU and provoked scattered attention in the Western media. When questioned by a reporter at Foreign Policy magazine that year, an unnamed NDU spokesman effectively disowned him, saying Garcia Covarrubias was technically not “an employee of the National Defense University” but a civilian employee of the Office of the Secretary of Defense “with the Defense Security Cooperation Agency serving as the Executive Agent. His current appointment ends on February 25, 2014.”

A senior U.S. government official said that after looking closely at Garcia Covarrubias’s record in recent days, we “found many links to torture allegations, from multiple open sources” as well as from nonpublic sources, which government experts considered credible. The official expressed frustration about Garcia Covarrubias’s hiring by NDU, explaining that “it is not that difficult to do the kind of vetting that would have caught these cases. There is a secret system we set up…It’s called Google.”

Garcia Covarrubias did not reply to questions emailed by the Center for Public Integrity to his published address. But his lawyers in Chile in 2013, José Luis López Blanco and José Alejandro Martínez Ríos, said in a court document that “in his military career, our client distinguished himself from his beginnings in the Military School until his promotion to the rank of Brigadier, and his later retirement from the Army as a very distinguished official.” Despite the fact that the investigation into “possible crimes committed at the Tucapel Regiment” had gone on for years, they added, “there has not been any evidence that permits Brigadier Garcia to be charged as the perpetrator responsible for any crime.” López Blanco did not respond to questions emailed to the address listed on his website.

Garcia Covarrubias and Ospina Ovalle are both graduates of the U.S. military’s School of the Americas, a U.S. Army school for Latin American military personnel that closed in 2000 following years of criticism that it had advocated torture in training materials and graduated some of the region’s most notorious dictators, including Manuel Noriega of Panama and Leopoldo Galtieri of Argentina.

As a teenage cadet in the mid-1960s, Ospina Ovalle attended an orientation course at the school, according to a database compiled by School of the Americas Watch, an advocacy group. The organization seeks to permanently close the school, which reopened in 2001 under a new name: the Western Hemisphere Institute for Security Cooperation, based at Fort Benning, Georgia.

Garcia Covarrubias took the school’s course “Combat Arms Orientation O-37” in 1970, according to the School of the Americas Watch database.

NDU has close ties to the institute: A former director of the Perry Center in the last decade was one of the founders of the institute, and a former deputy director of the Perry Center was an executive liaison there before joining the center’s administration. Delegations from the schools routinely visit each other and honor each other with awards such as the “Dr. William J. Perry Award for Excellence in Security and Defense Education.”

Sen. Leahy’s amendment to the Foreign Assistance Act, introduced in 1997 and enacted into law in 2008, requires recipients of State Department assistance or Defense Department-funded training programs for foreign security forces to be vetted through an internal State Department database, and bars assistance to individuals credibly charged with “a gross violation of human rights.”

Several government officials said the NDU had not interpreted the law as applying to its candidates for hiring and as a result did not submit the candidates to the State Department for appropriate review, however. That policy, they said, is under Pentagon review.

This story was published by The Center for Public Integrity, a nonprofit, nonpartisan investigative news organization. To follow more of the Center's national security reporting, go here or follow them on Twitter.