There's a great story in this month's Smithsonian magazine, about Guatemala's Disappeared. During the civil war, thousands of people went "missing" at the hands of the military goons who were running the country. Trouble is, nobody could prove anything... and the victims families never really knew what happened to their loved ones.
Then this happened:
"For years human rights advocates and others have sought to hold police and government officials responsible for the atrocities, but very few perpetrators have been brought to trial because of a lack of hard evidence and a weak judicial system. Then, in July 2005, an explosion near the [National] Police compound prompted officials to inspect surrounding buildings looking for unexploded bombs left from the war. While investigating an abandoned munitions depot, they found it stuffed with police records."
The Smithsonian article looks at the files, at their discovery, and at what their discovery means.