MOON Ki,
I agree about running away. It mitigates what can otherwise be a viable innocent explanation. If he reports it right away, he'll be in serious trouble, but probably ultimately with a better chance to walk. Even then, I think his goose would still be cooked by both the evidence and the inability to countenance any other explanation for it for the Negro with blood on his hands. To pick a random example, veritas would probably lock him up because he is from Cote d'Ivoire. I am not sure that type of persuasion is rare in Italy. He gave them way more than they required to lock him up.
@veritas,
Amanda probably walks with a "clear conscience" if she reports the crime. Given the leeway and generous benefit of the doubt she has enjoyed in this trial, she merely needed to report it. Maybe lie that she got home and found the girl dead. Stick with the lie. Once Guede is caught, no one would bother her. As it is though, Meredith was killed by more than one person. At least one of the murderers, maybe more, stayed behind to rearrange the scene.