On 15 April, radicals Nicola Sacco and Bartolmeo Vanzetti were accused of killing two men during a payroll hold-up in Massachusetts. Both men were found guilty in 1921. A six-year campaign for their release failed and Sacco and Vanzetti were executed on 23 August 1927. The controversial verdict sparked riots and it was later repudiated in 1977 by proclamation of Massachusetts governor Michael Dukakis.
Richert, Lucas Paul. "Trial and Execution of Nicola Sacco and Bartolomeo Vanzetti". The Literary Encyclopedia. First published 01 October 2008
[http://www.litencyc.com/php/stopics.php?rec=true&UID=1775, accessed 21 January 2017.]