"That girl is not me," Knox said of the prosecution's portrayal of her.
Knox said she is not the "dangerous, diabolical, jealous and uncaring" person she had been described as at her original trial.
"What you are going through, and what Meredith went through is unacceptable and incomprehensible," Knox said to the victim's family. "I don't know how you must feel, your suffering over a lost life."
Kercher was found partially naked and with her throat cut, in the bedroom of a house she shared with Knox. Prosecutors said Knox and her boyfriend killed Kercher, and attempted to make the crime scene look like someone had broken into the home.
Knox was sentenced to 26 years in prison in the death; her former boyfriend, Raffaele Sollecito, 25, was sentenced to 25 years.