The Heroes star plays the American student in Amanda Knox: Murder on Trial in Italy, which is based on the brutal killing of Knox's roommate, Meredith Kercher.
Panettiere admits she can't help but "root for" the 23 year old as she appeals against her conviction, and wants to see her freed - whether she's guilty or not.
The actress tells the Los Angeles Times, "I've lived a very different life than her. She went to normal school and worked at a coffee shop and was just going over to Europe, and I grew up acting. But we're both young girls. And I care about her. To a certain degree, guilty or innocent, I want to see her get out and be able to live the rest of her life. She's someone that I root for."
Knox is serving a 26-year sentence in an Italian prison for killing Knox in 2007 but a jury will meet next month (12Mar11) after new forensic evidence was discovered.