The Seattle woman, her former boyfriend and a third defendant were found guilty in the 2007 slaying of Meredith Kercher but her conviction was later overturned by a jury. An Italian appellate court then tossed out that jury's decision on appeal by prosecutors. It remains to be seen whether the United States would allow her to be extradited for another trial, CNN reported.
"I've received death threats since I've been home," she told CNN.
"There are not normal people who are fixated on me. And I don't know what they're capable of."
Knox told CNN in an interview to be aired Tuesday despite her fears she's considering returning to Italy for another trial to clear her name.
She said she finds it "incredibly unfair" people in Italy think she is arrogant because she has written a book about the case and stands by her right to defend herself.
"But at the same time, I want to prove to them that I care about what's going on," she said.
"I find it incredible that despite an absolute lack of evidence that connects me to this murder, I am still being judged based upon unrealistic and unreasonable expectations about how a young woman would react to a horrible situation.
"No one knows how they would react to a horrible situation until it happens to them. I have cried. I have been angry. I have been scared. And these were all things ... that I have shown, that have come out of me."
CNN said Knox reportedly received a $3.8 million advance for her book, "Waiting to be Heard."