I'm just surprised to see that the Kercher family is sad that the accused were acquitted.

Why do the Kercher family think that Amanda Knox and Raffaele Sollecito are guilty?

Update: Here's a clue to the family's thinking:

Whether that faith would remain solid after the court of cassation’s ruling, however, was unclear. Although the family have always been careful not to personalise the legal battle, they may well find the definitive clearing of both Knox and Sollecito hard to fathom. An earlier verdict by the court of cassation, which found Rudy Guede, an Ivorian, definitively guilty of Kercher’s murder, specified that the murder could not have been carried out by him alone, and that he must have had accomplices.

How, therefore, the only other people who have ever been seriously considered suspects in the case are now to walk free – for good – as a result of the same court is likely to be a bitter pill for the family to swallow.