July 15, 2015 7:20 PM ET
Here's what we know: Julius and Ethel Rosenberg were executed in 1953 for selling U.S. nuclear secrets to the Soviet Union after one of the most sensational Cold War-era espionage trials. They were convicted in 1951 owing, largely, to the testimony of David Greenglass, Ethel Rosenberg's brother.
Here's what we don't know: How credible Greenglass' testimony was in court. Read/hear more at the link above.