Prosecutors in Perugia filed a 111-page document seeking to reinstate the convictions of Knox and Sollecito in the stabbing death of Kercher, a 21-year-old British exchange student, the Italian news agency ANSA reported.
Knox was sentenced to 26 years in prison and Sollecito faced 25 years behind bars before an appeals court overturned their convictions four months ago.
The two spent four years in prison before being released.
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