His lawyers argue he was a convenient suspect because he happened to be dating Knox at the time.
His chances of freedom were boosted by a forensics review that said traces of Sollecito's DNA found on Kercher's bra clasp were unreliable and could have been contaminated since they were collected weeks after the murder was committed.
"I am hopeful that the court has heard well the arguments presented in the appeals trial and has realised that there isn't any evidence against my son and Amanda," said the older Sollecito.
His son has been cast as a "very strange follower" of the American, he said. Kercher, a student of Leeds University in northern England, was on a year abroad studying in Perugia when she was killed in November 2007.
Sollecito, whose once shaggy hair is now cropped short, usually sits in court chewing gum or listening impassively while cameras frantically click away at Knox sitting a few places away.
The focus has been on salacious details related to Knox's sex life, but Sollecito won his share of infamy when a photo posted on the Internet showed him wrapped in bandages holding a meat cleaver and a bottle of bleach. He has also been described as a knife collector.
Film of him kissing Knox, now 24, after the murder and shopping for lingerie with her have been held up as evidence of the couple's callous attitude towards the gruesome crime.
The Italian's supporters see him differently. One website that accepts donations for Sollecito's defence features pictures of a cherubic young boy at his baptism and birthday parties, and accounts from friends describing him as a loving, caring person.
Sollecito's father said he refused to speculate on why attention has focused on Knox rather than his son.