The university says it had no indication of anything being wrong.
Fearing reprisals, neighbours who had called the police refused to give their names.
For the 21-year-old American student is facing life behind bars in an Italian jail after the brutal sex-murder five weeks ago of British student Meredith Kercher, who had been allocated a room in the same apartment as Knox during a gap year exchange in Perugia.
Police made only one arrest: the person they held responsible for the party and the disorder.
But despite the Italian Supreme Court throwing out the case for good in 2015, there are still many who believe Knox and Sollecito were part of the brutal killing.
Any mention of the party in June at which Knox was arrested elicits a flat response.
Her throat had been cut three times and she had bled to death after being locked inside her own room.
In late 2007, the eyes of the world were drawn to the Italian city of Perugia for the gruesome murder of a foreign exchange student and twisted tales of sex games gone wrong that emerged from its picturesque facade of steep mountain streets and centuries-old buildings.