There is not enough evidence to place an Italian suspect jailed in connection with the slaying of a British student at the crime scene, his lawyer said in court documents obtained Thursday.

A judge must rule Friday on whether suspect Raffaele Sollecito and his then-girlfriend, American Amanda Marie Knox, should remain jailed in connection with the killing of Knox's flatmate, Meredith Kercher. The two were arrested Nov. 6.

In a document prepared for Friday's hearing and obtained by The Associated Press, Sollecito's lawyers dismissed prosecutors' allegations that he was at the crime scene the night of the slaying. Sollecito says he was at his own Perugia apartment, working at his computer.

Sollecito "from 20:30 of Nov. 1, 2007, until the morning of Nov. 2 was always at home and therefore did not have any role in the murder of the poor Meredith Kercher," the defense document says.

The defense says analyses on Sollecito's computer show he had been logged on. Prosecutors say police have proven that the computer was connected to the Internet but without anybody accessing it overnight.

According to the defense, there isn't enough evidence that a bloody footprint found near Kercher's body matches Sollecito's shoes, as prosecutors maintain. The defense says the print is not clear enough to allow for a certain match.

Sollecito, a 23-year-old student who was dating Knox at the time, is expected to attend the hearing Friday, said his lawyer, Marco Brusco. Knox also is expected to appear in court.

DNA from Knox and Kercher was found on a knife that investigators believe may have been the murder weapon; the knife was found in Sollecito's home.

But "no compatibility has been ascertained between the knife in question and the wounds inflicted on the victim," said the defense document.

Knox, a 20-year-old from Seattle, was quoted as saying she was calm. An Italian lawmaker who visited Knox on Wednesday relayed her quotes to the Turin newspaper La Stampa.

The lawmaker, Osvaldo Napoli, told the AP that Knox is spending her time reading books and answering letters.

"She told me: 'I am extremely serene and tranquil. I have faith in the Italian courts; I await the judgment serenely,"' Napoli told the AP Thursday.

Knox has given conflicting statements since Kercher was found dead in their Perugia apartment on Nov. 2. Kercher, a 21-year-old Leeds University student, was killed by a knife wound to the neck, and prosecutors said she died fighting off a sexual assault.

Knox first said she wasn't home the night of the slaying, but later told prosecutors she was in the apartment and had to cover her ears to drown out Kercher's screams.

The top investigating prosecutor, Giuliano Mignini, says the body of evidence against Knox has only grown as the probe continued.

In addition to Knox and Sollecito, a third suspect, Rudy Hermann Guede, is being held as a suspect. He was arrested in Germany and is to be extradited to Italy.

All have denied any wrongdoing.