They were both freed after four years in prison when an appeals court ruled in 2011 that much of the evidence was poorly handled, raising questions that key forensic evidence had been contaminated, and that the prosecution had failed to produce a motive for Knox to kill Kercher.
Knox returned home to Seattle and was stunned when Italy's Supreme Court ordered another appeals court to look at the case again. This time, the appeals court found Knox and Sollecito guilty of murder.
In detailing the latest decision, the court dismissed the sex game gone awry theory, but attributed the murder to bad blood between Knox and Kercher that erupted over the theft accusation.
The motivation also said there was evidence that more than one person was involved and more than one knife was used in the attack on Kercher, which meant that Guede did not kill Kercher by himself. It claimed that Guede restrained Kercher while Knox and Sollecito wielded knives.
The court sentenced Knox to 28.5 years in prison and Sollecito to 25 years. The defendants are expected to appeal this latest sentence to Italy's supreme court.