Fast-forward 17 months and, in a case with as many twists and turns as a thriller, both face the prospect of reliving the whole process again -- this time in a Florence appeals court.
Sollecito has already published his memoir, titled "Honor Bound: My Journey to Hell and Back with Amanda Knox."
In it, he writes that at times, he was uncomfortable with Knox's "bizarre behavior" after Kercher's death, which he says prosecutors used against both of them.
Knox's full version of events has not yet been heard.
But her own book will be "a full and unflinching account of the events that led to her arrest in Perugia and her struggles with the complexities of the Italian judicial system," according to publisher Harper Collins.
Based in part on journals kept while she was in Italy, it represents "a remarkable story of innocence, resilience, and courage, and of one young woman's hard-fought battle to overcome injustice and win the freedom she deserved."
Licentious or lied-about?
The book is likely to be closely scrutinized by those curious to know which image of Knox is a true likeness.
Some journalists have portrayed Knox as an overly trusting college student who some believe was railroaded by the Italian justice system. Other media paint her as a licentious, manipulative young American still trying to get away with murder, despite an alleged confession, which she quickly recanted, and a conviction, later quashed.
The fact that she was separately convicted of defaming Patrick Lumumba, a club owner whom she falsely accused of killing Kercher, feeds into the latter narrative. The Supreme Court did not order a retrial on this count.
But to Knox's friends and family, it's a no-brainer. They grimace at the description prosecutors painted of her as a resentful American so angry with Kercher that she exacted revenge during a twisted sexual misadventure.
Nothing in her past indicated she had the desire or capacity to kill anyone, let alone a friend, they say. One friend told CNN she was the kind of person who would pick up a spider and take it outside rather than kill it.
More than anything, they say, her life had been all about immersing herself in new experiences and creating opportunities to travel abroad.
Growing up in Seattle, Washington, Knox was an easy daughter from the start, said Edda Mellas, her mother.
She was a child who never had to be told to do her homework or go to bed on time. She maintained a balance between a life indoors, where she studied regularly and read for pleasure, and a passion for outdoor activities and sports, in particular gymnastics and soccer.
Knox's desire to study foreign languages and experience different cultures also became apparent early on, Mellas said.
She took Latin in middle school and began expressing a desire to travel abroad. Even though her parents told her they couldn't afford a private high school, she applied on her own and was accepted with a substantial scholarship.
She learned Japanese in high school and spent time in Japan as part of her studies, her mother said.
"She loved learning languages. She thought about being an interpreter. She really wanted to be a writer and I said, 'Maybe you need to get a day job while you're trying to make money being a writer.' And then she thought about being an interpreter. Languages were definitely her kind of gift."