"Suosso's Lane" is not a courtroom novel, nor is it a straightforward dramatization of the factual record of Vanzetti's life in Plymouth. Why not -- a reasonable question -- simply stick to the facts? Historians do that, and they should.
But fiction is storytelling, and we need stories to give meaning to events. Stories are receptacles of meaning created by individuals and societies to interpret, advise, and make sense of the big mysteries and routine deeds of human experience. Folk tales, fairy tales, legends (emperors who want to cage the nightingale, kings who want the Midas touch), Greek myths, the book of Genesis in the Bible... We can all think of stories that matter to us.
Further, "Suosso's Lane" goes beyond historical fiction by developing a 21st century storyline based on reactions to the earlier events (Vanzetti in Plymouth), with characters forced to deal with some of the same deep social issues.
The principals here are:
-- Mill Becker, a young history teacher, who moves to Plymouth after being hired for his first real academic job at a nearby community college. Mill complains about his students and needs to develop a firmer grip on who he is, accept his limitations, and trust strengths. His fascination with, and desire to learn more about, Vanzetti drives the plot.
-- His wife, Bernie Becker, a committed human services worker. Though more grounded than her husband, she has rescue fantasies about one of her clients (having fallen afoul of the law, he needs to be kept on the right path). Bernie has her own opinions; she asks Mill, 'Why were anarchists so against unions?'
-- A second plot-driver -- here's a familiar character! your nosy local reporter (his working life, btw, is a lot more interesting than mine ever was), Maurice Jeter. He's investigating a real cold case, a 60-yr-old suspicious death of a Plymouth policeman. How can this death connect to the Sacco Vanzetti case? Well that's what fiction is for.
-- Finally, Ike, the 'new immigrant' client Bernie seeks to help, works at a big box store (that I'm not allowed to call Wal-Mart). He finds parallels to V's story in his own life. He's in this novel because immigrants today do low-paying service job (they've replaced unskilled factory labor), as many of them as they can find to patch together an income, live in crowded conditions, save in order to send money home, or to bring loved ones over.
Our response (judging from the tenor of our current politics) is to try to make things harder for them.
So (quick plot wrap-up) Mill Becker is trying to find rumored documentary evidence, a letter or note of some sort, that would prove that Vanzetti could not have been at the scene of the Braintree crime that day (April 15, 1920). How well he does you'll have to read the book to find out.