"It would feel like a train wreck," Amanda Knox told the Guardian, shortly before being found guilty of the murder of Meredith Kercher for the second time.

In a series of exclusive interviews in the days building up to the latest verdict, Knox said that in such a situation she hoped the US government would refuse to extradite her: "I'm definitely not going back to Italy willingly. They'll have to catch me and pull me back kicking and screaming into a prison that I don't deserve to be in. I will fight for my innocence."

The American student's train has indeed hit the buffers. On Thursday the appeal court in Florence re-convicted Knox and her Italian former boyfriend Raffaele Sollecito of the brutal murder of the much-loved British student in 2007.

At the time, Knox and Kercher were gap-year students living in the picturesque hilltop town of Perugia. The case was fodder for both the tabloids and the chattering classes – a beautiful middle-class female student stabbed in the throat by another beautiful middle-class female student. Knox was labelled by prosecutors as a chilly, sex-obsessed, woman-hating psychopath. Her friends maintain that couldn't be further from the truth; that she was a rose-tinted idealist who saw the best in everyone.

Knox told the Guardian this week that she had been in touch with Sollecito during the trial, but she denied that he had asked her to marry him in order to gain US citizenship and escape imprisonment, as had been reported in some newspapers. "It is not true. I don't know where that came from."

Knox said she was relatively fortunate in that she had been able to return to America, and that she was worried for Sollecito. "He's really scared. And really vulnerable. I think he feels abandoned by his own country. Where's he going to run and hide? It's a shame that more people aren't fighting to protect him."

Asked how she would feel if he was imprisoned while she remained free, she said: "That would drive me crazy. I don't know what I could do, but I'd do it. There would be action. And there would be an outcry."

She said the whole experience had irreparably damaged her. "I am a marked person, and no one who's unmarked is going to understand that. It's very intimidating. I don't even know what my place is anymore. What's my role in society? Who am I, after everybody has branded me?"

Knox was convicted of slander in 2009 after falsely naming Patrick Lumumba, her boss at the bar where she worked, as the murderer – a claim she quickly withdrew. She said she was physically hit and psychologically tortured during an interrogation that lasted four days, and is hoping to have the slander conviction overturned at the European court of human rights.

Knox said that even though she would always protest her innocence, for years she blamed herself for her conviction. "I thought I was weak and therefore deserved it. I thought there was something wrong with me because how could anybody do what I did. "

It was only later that she discovered false confessions were commonly made by exonerees. "If you look at murder, 62% who are later exonerated, falsely confess. We all seem to think as innocent people we're not going to be screwed with enough psychologically to question everything we know … but goodness, that's not the case at all."

She said she now felt a responsibility to campaign for the wrongfully convicted and to publicise the risk of aggressive interrogation leading to false confession.

"The only thing I can do is testify to what happened to me. You don't have to believe me, but believe that it happens to other people. Until people realise that, they're not going to believe me, so all I can do is say what happened and show who I am and hope that that's enough." Yesterday, the court in Florence ruled that it was not enough.