That prosecution's evidence included a spiral notebook seized from Entwistle when he was arrested in February 2006. In the pages of the book, there is a draft letter in which Entwistle pretends to be a "close friend" and pitches a proposal to sell his story to the highest bidder.
"What's of interest to us is what price you would be willing to pay for the exclusive rights to the full story. … We are leaving it open to the highest bidder," wrote Entwistle. And, he added, there would be enough material to last "a week."
The prosecution has long argued that Entwistle killed his wife and child because this suburban dad was dissatisfied with his sex life and swimming in debt. In closing arguments, assistant district attorney Michael Fabbri said that Entwistle had "reached a tipping point."
Evidence released in June showed pages and pages of Internet sex searches and e-mail correspondence with women in which the supposedly happily married Entwistle indicated his eagerness to have sex with strangers.
There was also a file folder of collection notices addressed to Rachel and Neil Entwistle from the time period in which they lived in England.
Perhaps among the more intriguing evidence items was a letter found in Neil Entwistle's backpack. At first glance, it seems like a love letter -- an impassioned description of a love that ended too soon.
But given that the killer was intent on selling his story, it could be that the writings are nothing more than a fantasy first chapter in a murderer's memoir.
Entwistle wrote, "As a husband I could never dream for more. She was my soul mate and my very best friend. The love we shared knew no bounds, a love that brought on both comfort and excitement. ... We would model our love on four roses, red for passion, yellow for fidelity and white for pure love. The combination of these roses is the orange and that is what we are to each other."
Entwistle went on to describe Rachel in glowing terms and said "everyone who has been in her company will have been touched by her kindness, her love and her energy. And that is what I hope people will remember most."
In a victim impact statement in the Massachusetts courtroom Thursday, Rachel Entwistle's family said what they would remember most was a beautiful woman and a "perfect mother."
Priscilla Matterazzo, Rachel's mother, told a hushed courtroom that her family had been sentenced to an "eternity of emptiness." Matterrazzo went on to describe her family's pain. "Suffering does not begin to describe what we have been enduring without our beloved Rachel and Lillian," she said.
She also lashed out at Entwistle, calling him "low and despicable" for allowing his defense counsel to accuse Rachel of a murder-suicide in their closing arguments.
After Kottmyer announced Entwistle's sentence, she added one final ruling: Entwistle is "not to profit in any way from the sale of his book or otherwise to any media outlet."
Entwistle came into court Thursday looking every inch the computer engineer he used to be. Dressed in a suit and tie, Entwistle glanced briefly at his family, which sat huddled in the front row.
Entwistle left the courthouse in an orange jumpsuit, with shackles chained to his wrists and legs -- preparing to spend the rest of his life behind bars.