Sacco and Vanzetti were electrocuted at Charlestown State Prison on August 23, 1927.
(Madeiros was also electrocuted that same night for the murder of a bank cashier, a crime wholly unrelated to the South Braintree robbery and murders.) Because Sacco had been on a hunger strike his body had lost salt and water, elements that conduct electricity. To compensate, he received a higher voltage than Vanzetti, as indicated on the certificate below.
Funeral procession for Sacco and Vanzetti, August 28, 1927, viewed from Tremont Street in Boston.