According to the Library of Congress Webcasts site:

"It was a bold and brutal crime: robbery and murder in broad daylight on the streets of South Braintree, Mass., in 1920. Tried for the crime and convicted, two Italian-born laborers—anarchists Nicola Sacco and Bartolomeo Vanzetti—went to the electric chair in 1927, professing their innocence. Journalist Susan Tejada has spent years in the Library of Congress and elsewhere investigating the case, sifting through diaries and police reports and interviewing descendants of its major figures. She discovers little-known facts about Sacco, Vanzetti and their supporters, and develops a tantalizing theory about how a doomed insider may have been coerced into helping professional criminals plan the heist."