Knox, 25, was originally arrested in November 2007 after one of her roommates, Meredith Kercher, was found dead in her bedroom.
Knox was sentenced to 26 years in prison, but was sent home after having her conviction overturned in 2011.
On appeal the appellate court noted that the murder weapon was never found, that DNA tests were faulty, and that Knox and her boyfriend had no motive to kill Kercher.
It's unlikely that Knox will be compelled to return to Italy, even with this setback.
Per the AP's analysis yesterday: "Italian
As the NYT's Rachel Donadio notes, the court's decision only pertains to the technical matters of the case, not the merits of the case.
Here's what Knox had to say (via ABC News Foreign editor Jon Williams):
Knox: "Painful to receive news. Prosecution’s theory of my involvement in Meredith’s murder repeatedly revealed to be unfounded & unfair."
— Jon Williams (@WilliamsJon) March 26, 2013
Knox: "Will face continuing legal battle confident in truth & with heads held high in face of wrongful accusations & unreasonable adversity"
— Jon Williams (@WilliamsJon) March 26, 2013
Rudy Guede, a young drifter from Ivory Coast, is currently serving a 16-year sentence after being convicted of sexually assaulting and stabbing Kercher.