But in Europe, some see her as a privileged American who is getting away with murder, embroiled in a case that continues to make global headlines and reinforces a negative image of U.S. citizens behaving badly—even criminally—abroad without any punishment.
As she remains free in the U.S., the perceptions will likely fuel not only the debate about who killed Meredith Kercher in 2007 and what role, if any, Knox played in her death, but complicate how the U.S. and Italian governments resolve whether she should be sent to Italy to face prison.
"It's been a polarizing case, and that polarization will remain," said Anne Bremner, a Seattle attorney and Knox supporter.
The divergent views on who killed Kercher are rooted not just in the typical dynamics of a legal case in which the two sides hold opposing narratives, but also in the differences between the justice systems in the U.S. and Italy, and examples of Americans avoiding Italian justice.
After being first convicted and then acquitted, Knox and her one-time boyfriend, Raffaele Sollecito, were convicted again Thursday, following their third trial. Knox was sentenced to 28 1/2 years, Sollecito to 25 years.
The tone of some British newspaper coverage reflected skepticism about Knox's protestations of innocence. "Shameless in Seattle" was the front-page headline on Saturday's Daily Mail, which referred to Knox's "brazen TV charm offensive to escape extradition."
Any decision on whether to return Knox to Italy will ultimately be made by the U.S. State Department.
There have been other high-profile cases in which Italians hoped in vain to have Americans face justice there, notably the case of a U.S. Marine jet that sliced a gondola cable in the Italian Alps in 1998, killing 20 people.
Under NATO rules, the U.S. military retained jurisdiction, and the pilot was acquitted of manslaughter.
More recently, in 2009 Italian courts convicted—in absentia—26 CIA and U.S. government employees in the kidnapping of an Egyptian cleric suspected of recruiting terrorists in Milan.
Some lawyers familiar with the process say Knox has little hope of avoiding extradition under the terms of the U.S.-Italy treaty, but that won't stop her supporters from mounting a campaign to keep her in the U.S.
They're appealing to American principles about trying someone multiple times for the same crime, even though under Italian law her earlier conviction and subsequent acquittal were never finalized, and even her third trial was considered part of the first prosecution against her.
They're also asking how one appellate court could find her actually innocent, while another court convicts her beyond a reasonable doubt.
Kercher, 21, was found dead in the bedroom of the apartment she and Knox shared in the town of Perugia, where they were studying. Kercher had been sexually assaulted and her throat slashed.
Investigators claimed it had been a drug-fueled sex game gone awry—an accusation that made the case a tabloid sensation.
Knox, now 26, and Sollecito, now 29, denied any involvement. After initially giving confused alibis, they insisted they were at Sollecito's apartment that night, smoking marijuana, watching a movie and having sex.
But police and news media focused on what was described as Knox's bizarre behavior afterward—shopping for underwear, embracing Sollecito and turning cartwheels for police as she became a suspect.
Meanwhile, a third defendant was arrested and convicted separately: Ivory Coast-born Rudy Guede, a drug dealer whose DNA was found was found in the room where Kercher was killed, and who acknowledged being there the night of the murder.
For Knox's detractors, there remains that after her arrest, she implicated an innocent man—Diya "Patrick" Lumumba, the Congolese owner of a pub where Knox occasionally worked.
Knox said she made those statements under duress during an overnight interrogation, when she had neither a lawyer nor a professional interpreter, and when she had been asked to imagine what might have happened. Her supporters say such an interrogation would never have been allowed in the U.S.
For Knox's supporters, the initial police theory about the sex game was far-fetched, much more complicated than what they saw was the more plausible explanation that Guede killed Kercher by himself.
And the fact that prosecutors abandoned that theory for the most recent trial, instead arguing that the motive was an argument over cleanliness in the apartment, further illustrates that law enforcement was grasping, they say.
As Knox awaits her fate, the questions over who killed Kercher will continue. Knox's supporters, for example, released an electronic book arguing that Guede acted alone in the killing. Kercher's siblings wonder if they'll ever know what really happened.
Some in Italy, however, seem to be coming to one conclusion: the prosecutors didn't have much evidence.
The Rome daily La Repubblica wrote Friday that the third verdict confirms that the case "from the very beginning has been judged more on the basis of sensation than actual evidence."
It suggested Knox and Sollecito had "always been the perfect culprits," and that "in reality, what is probably more at stake than assigning responsibility for a murder is the prestige of a part of the magistrature and the Umbrian police."
Associated Press writers Jill Lawless in London and Colleen Barry in Florence, Italy, contributed to this story.