Rudy Guede is the only person convicted in the 2007 killing of the British student in Perugia, Italy.

The movie, which also stars Abigail Breslin, "reinforces an image of me as a guilty and untrustworthy person," Knox wrote.

The American woman who famously spent four years in an Italian prison had some choice words for the pop star.

Knox was at the center of a media frenzy when she was convicted and then acquitted of the murder of Meredith Kercher.