Testimony by Colombian statistical expert Daniel Guzmán provided key evidence in the conviction of two former police officers found guilty in the 1984 forced disappearance of Guatemalan student and union leader Edgar Fernando García. In a historical ruling, two former officers of the Guatemalan National Police - disbanded in 1996 as part of the peace accords ending the internal armed conflict - were each sentenced to the maximum term of 40 years in prison for their role in García’s disappearance.

On October 28, 2010, twenty-six years after the crime against García, the Eighth Tribunal of the Guatemalan Supreme Court in Guatemala City sentenced Abraham Lancerio Gómez and Héctor Roderico Ramírez just ten days after the start of the case. Two other former officers suspected in the crime remain at large. The verdict has established forced disappearance as a crime in the Guatemalan judicial system and prompted the Guatemalan Public Ministry to investigate other members of the National Police involved in the case, high-ranking officers among them. “I feel proud to have been able to support justice in Guatemala with my statistical, technical contribution,” said Guzmán, who is a consultant for the Human Rights Data Analysis Group at Benetech, a California nonprofit. “Most importantly, García's family is starting to believe some kind of justice is possible.”

The trial in the case of Edgar Fernando García´s disappearance in Guatemala is exceptional in several respects. First, the sentences against the two former policemen are the first based on evidence found by researchers among the estimated 31.7 million documents contained in the Historical Archive of the National Police. Second the guilty ruling against the accused is the third such verdict passed in Guatemala against forced disappearance. Since there were two similar rulings issued in 2009, this most recent verdict will establish a lasting judicial precedent for future cases that can help hold other perpetrators accountable.

Edgar Fernando García was 26 years old, an engineering student, union activist, and member of the clandestine Guatemalan Workers´ Party (PGT in Spanish), when he was detained by National Police agents on a Guatemala City street. His whereabouts are still unknown. With his disappearance on February 18, 1984, he left his young wife and 18-month old daughter behind.

During the reading of the verdict, it was announced that among the evidence taken into account in the trial was expert testimony from Guzmán that calculated the percentage of documents about García known by different police units. Guzmán and his colleagues at Benetech, with technical support from the statistical survey research organization Westat, of Washington, D.C., carried out a quantitative analysis of the official records found in the National Police archive, from which most of the essential proof in the case emerged.

The statistical analysis by Guzmán and his colleagues, based on random sampling of the estimated 31.7 million documents in the Archive generated between 1960 and 1996, centered on the quantity and the movement of the documents found there. According to Guzmán, units responsible for direction and coordination of National Police policy were acquainted with proportionately more than twice the number of documents related to the Edgar Fernando García case than with the total of documents in the Archive. By calculating the percentage of documents known by different police command structures, analysts can reach conclusions about relationships among security forces and communications between the army and police. This evidence is critical because historical data has shown that the Guatemalan army was the force most involved in human rights violations against civilians. Prosecutors hypothesize that the National Police may have carried out crimes against civilians in coordination with the army.

Guzmán’s findings helped to support arguments by prosecutors that relatively high-level officers of that institution were aware of the planning, the design, the orders given, and the supervision of the type of operations like the one that resulted in García’s disappearance, which were carried out against activists and perceived subversives during the time of the internal armed conflict in Guatemala.

The data that Guzmán used in his testimony was based on three years of coding key variables from random samples of documents drawn from the National Police archive. Random sampling is a statistical methodology used when the whole of reality cannot be observed directly. An extrapolation is made from what is known and directly observable to what has not been observed and therefore remains unknown. In the case of the Historical Archive of the Guatemala National Police, for example, it was impossible to read the estimated 31.7 million documents produced there and so analysts created a physical map of the archive and sampled the documents. Sampling was also necessary to ensure that the documents were chosen at random and not selectively analyzed.

The science of statistics has been used by Guzmán and his colleagues at Benetech in other countries, including Colombia, to carry out estimates of massive human rights violations. In February 2010, on the basis of partial data, Guzmán and his colleagues presented a scientifically based statistical estimate of the total homicides and forced disappearances that took place in the Department of Casanare in the period 1998-2007. This was documented in the 2010 Benetech report, "To Count the Uncounted: An Estimation of Lethal Violence in Casanare."

The testimony provided by Guzmán and others in the García case fights impunity and strengthens the rule of law to resolve crimes committed during Guatemala’s years of conflict. The statistical analysis carried out in Colombia by Guzmán and his colleagues also provides historical clarification and may perhaps help Colombian families of the disappeared find the peace and justice found by the family of Fernando García.