Jorge Villagran supervises one of the most important and sensitive projects in Guatemalan history: preserving and digitizing a massive trove of documents from the National Police files so that the country can gather evidence about human-rights abuses and bury the last vestiges of a brutal civil war.

Long thought destroyed, lost or simply nonexistent, the estimated 80 million documents were discovered by accident in July 2005 in abandoned, half-finished buildings in Guatemala that were overrun with bats, rats, mould, termites and insects. Authorities believe the archives from the National Police contain invaluable evidence about human-rights atrocities committed during Guatemala's 36-year civil war that killed 200,000 people and ended with a peace pact in 1996. (The accord between the government and leftist guerillas abolished the National Police. Guatemala is now a democracy.)

"The discovery of these files is extremely important, because their existence had always been denied, and now it turns out that not only do they exist, but their volume is massive," says Villagran.

For 10 years, human-rights groups have worked tirelessly to document crimes that occurred during the war. But official evidence proving that the police and the military kidnapped, murdered and tortured citizens because of their political beliefs has been hard to come by. Until now.

Villagran works for the government-backed Human Rights Ombudsman Office, whose mission is to clean, safeguard, organize and analyze the documents in search of evidence of past crimes. The goal is to bring human-rights abusers to justice. "All the testimonies gathered [in previous investigations] are from victims. This is the other side of the coin. These are official documents," Villagran says, explaining the official version of history.

First, Villagran agency needed to protect the documents, by refurbishing the abandoned document storehouses. Security guards are on duty around the clock. Next came records preservation.

A project to digitize the documents and load them into databases is under way to make the documents available electronically for analysis. (Future plans call for posting the documents on the Web.)

Villagran says his agency uses a Kodak scanner to digitize documents and a Minolta scanner to digitize bound records. Workers often have to clean the documents and feed sheets by hand. "There are books, notebooks, individual sheets, standard paper, onion paper, coloured paper, paper covered with mould, old paper, new paper," Villagran says.

Villagran's team has worked with consultants to create an archiving system to classify records by type to help investigators sort through them. "Mining these documents for their human-rights information depends first on the kind of archival work you do and whatever technologies you bring to bear on the materials," says Kate Doyle, senior analyst at the National Security Archive, a nonprofit research group in Washington advising the ombudsman's office.