Knox's judge explains guilty verdict

[Fred Sanders]

16. Both the defendant and the prosecutor can appeal against the judgement before the Corte d'Appello

Do not forget that this "trial" is an appeal of the first appeal that overturned the trial conviction.

For a defendant to be convicted, the Judge must be internally convinced (Italian law requires the Judge's intimo convincimento); because of that, there are no rules that predetermine the weight to be attributed to any given piece of evidence, so even credible admissions [of guilt] can do no more than reduce the amount of extrinsic evidence necessary for a finding of guilt.[20]

Before the beginning of the trial phase, the parties file a brief, detailing all evidence they want to present – the parties have to indicate by name every witness and precise what these will be asked –; both the defendant and the prosecutor can cross-examine each other's witnesses. The Judge may choose not to admit any testimony that appears patently superfluous, reject irrelevant or improper or irregular questions – such as leading questions – and also ask questions to the witnesses and experts.
The Judge can also, but only when absolutely necessary, order additional evidence to be taken.

Appeals

The Court of Cassation cannot rule on the merits of a case, so, when quashing a verdict issued by a lower Court, it is possible that the members of the Court realize that further fact-finding is required to reach a final judgement.

In these cases, the Court quashes the previous judgement, but it remands the case to another criminal division of the Appellate Court that issued the appealed decision or, if it is not possible, to a criminal division of the nearest Appellate Court.
The Judge ad quem (the one the case is remanded to) can try de novo the defendant, but must conform to the contingent points of law applied by the Court of Cassation. The verdict issued by the Judge ad quem is appealable before the Court of Cassation.

Yes, it is very, very complicated and utterly foreign to Americans and anyone familiar with the British system.