Prosecutor Alessandro Crini said testimony from a homeless man who said he saw Knox and Raffaele Sollecito near the apartment the American woman shared with Kercher, a fellow exchange student, in Perugia on the night of the killing was "trustworthy," the Italian news agency ANSA reported.
The murder created an international stir since Knox and Sollecito, her boyfriend at the time, were accused of killing Kercher in a sex game gone wrong. Knox and Sollecito were convicted in 2009 before they were acquitted on appeal in 2011. Earlier this year, Italy's top court reversed the 2011 decision by the appeals court and ordered a new trial to be conducted in Florence.
The prosecutor also asked the court to consider as reliable testimony from a shopkeeper who said he saw Knox in front of his store the morning after the murder. Knox and Sollecito have both testified they were at Sollecito's apartment at the time of the killing and later.
Sollecito attended Monday's hearing, while Knox, who is from Seattle, was in the United States.
The trial began in September and a sentence is expected in January.