The moldy records were found by accident in 2005 in an abandoned section of a police compound in Guatemala City. Some of the records date back more than a century, their faded pages describing the daily bureaucracy of repression employed for decades by Guatemala's government.

Of most interest to investigators are records from 1975 to 1985, the most violent period of Guatemala's civil war, during which 160,000 people were killed and 40,000 disappeared.

Although workers from the government's human rights prosecutor have so far examined only about 5 million pages of the records, many are confident that what they are finding will shake up this traumatized land.

"During the conflict there was a sense of fear, for you never knew who was behind things," said Bishop Alvaro Ramazzini Imeri of San Marcos, president of the Guatemalan bishops' conference. "The uncovering of the archives marks that we're entering a different era. There is an opportunity to know who was involved in this, to rewrite the history of violence in our country and identify who the killers were."

Guatemala's civil war ended in 1996, and the final report of a U.N.-supervised truth commission includes 165 pages of letters that the commission wrote to the president and other government officials demanding access to police and military records. The commission always received the reply that such records did not exist.

After the secret records in Guatemala City were discovered, investigators from the human rights prosecutor's office seized 34 other sets of records in provincial and neighborhood police offices.

No files were uncovered from the military, perhaps the most brutal armed force in the hemisphere during the years of the civil war. Human rights activists had long hoped to discover the army's archives, which would shed light on the government's "scorched-earth" campaigns during the civil war.

Yet the police archives do include records from the Joint Operations Center, an office that coordinated the activities of all the country's security services. An initial analysis of 3,000 pages selected at random showed that 15 percent of the documents shed light on human rights abuses.

A preliminary report on the project, due out late this year, will include concrete examples of police records that show when and where certain individuals were arrested and never heard from again, although the police always denied having detained them. Fingerprint records and photographs of tortured bodies interred in urban cemeteries are being matched to lists of the disappeared prepared by organizations of their family members.

Alberto Fuentes, an official of the human rights prosecutor's office who manages the day-to-day operations at the archives, said information gleaned from the documents will provide closure to many families who have never learned the fate of friends or family who disappeared.

"There are thousands of families of disappeared persons, families that can't end their grieving. The military and the police took away our right to life, but they also took away our right to death," said Fuentes, a former Catholic social services worker whose brother, Julio, disappeared in 1982.

Since the war's end, scores of mass graves have been exhumed in the countryside. Investigators hope the police archives will yield clues leading to the remains of those killed in the cities.

"We have 15 years of carrying out exhumations, and we've recovered 5,000 bodies, but only one of those disappeared in the capital. Now we can follow the leads to many others," said Fredy Peccerelli, director of the Guatemalan Forensic Anthropology Foundation.

Several former military leaders have expressed outrage at the prospect of the secret archives being made public. Security around the operation is tight; scanned documents are immediately backed up on a remote server elsewhere in Guatemala and one in Switzerland.

Church workers are often the subject of the reports being found. One document, a blue faded carbon copy of a June 4, 1973, memo to the head of the detective branch, passes on an informant's report: "On weekends, youth groups led by Jesuit fathers are going out to raise consciousness among the indigenous in Quiche, asking such questions as 'Is the Ladino (person of mixed ancestry) treated the same as you? Who is better and why?'"

Velia Muralles, who heads a section assigned with interpreting what investigators find in the archives, says the reports show how anyone, especially teachers and church workers, who asked uncomfortable questions about discrimination became a suspect.

"Simply asking questions about why the Ladino and indigenous were treated differently was proof that they were subversives," she said.

Taken as a whole, according to investigators, the ...