Thomson Reuters
File photo of Amanda Knox reacting during her interview on ABC's "Good Morning America" in New York
Her ex-boyfriend, Raffaele Sollecito, was also cleared after a legal saga that dragged on for seven years and landed the now-27-year-old Knox in an Italian jail for four years before she finally returned home to the US.
The murder case went to Italy's high court after an appeals court found Knox guilty of the killing last year. Kercher was found dead in the apartment she shared with Knox while studying abroad in Italy in 2007. She had more than 40 stab wounds on her body and her throat slit.
In its decision Friday, the Italian high court annulled the convictions and decided not to order a new trial, the Guardian reported. This means that Italy won't try to have the US extradite Knox.
Knox's supporters in her hometown of Seattle are "ebullient and relieved," according to the Guardian. "Thank god it's over, they can get on with their lives," Candace Dempsey, author of "Murder in Italy," a book about the case, told one of the Guardian's reporters on the ground in Seattle.
The Knox case exposed differences in Italy's justice system, where defendants can be tried over and over again for the same crime.
Last year's conviction wasn't the first for Knox. She and Sollecito were first found guilty of the murder in 2009. They were sentenced to 26 and 25 years in prison, respectively, for the murder, but the legal saga didn't end there.
Under the rules of the Italian justice system, if either side is unhappy with a verdict, they can appeal. It's possible for verdicts to be upheld and overturned multiple times before appeals are exhausted.
Knox is currently free in the US and previously said that if she were convicted, she would "become a fugitive." She spent four years in prison in Italy during the trial and after the initial guilty verdict was handed down.
During the first trial, Italian prosecutors claimed that Knox and Sollecito killed Kercher during a sex game gone wrong. A third person, drifter Rudy Guede, has also been convicted of Kercher's murder. Prosecutors allege that he worked in conjunction with Knox and Sollecito.
A court overturned Knox and Sollecito's guilty verdicts in 2011 after they appealed their convictions, but a higher court rejected the acquittals and demanded a retrial, which led to the 2014 conviction.