The U.S. Holocaust Memorial Museum and Ancestry.com's World Memory Project allows people to sift online through hundreds of thousands of documents that previously required a painstaking manual search.

The mystery surrounding the fate of the Swedish diplomat who saved thousands of Jews in Budapest has lingered for more than six decades. A Russian security archivist says his agency is not hiding details on what happened to Wallenberg who disappeared after being arrested by the Soviet Red Army.

In 1977, the family of retired autoworker John Demjanjuk was astounded when he was accused of having been a guard known as "Ivan the Terrible" at a Nazi death camp in World War II. His case was considered the last of the Nazi war crimes trials, but this week, prosecutors in Germany said they were reopening hundreds of investigations. Host Audie Cornish talks with historian Deborah Lipstadt about how that might play out.

Journalist Martin Davidson knew his German grandfather had something to hide. After the old man died, Davidson discovered the secret: He'd been an officer in the SS.