Ok, I'll run with that.

Most obviously there is a general trend that people become less likely to make accurate deductions once they are emotionally invested in the decision (consider their reactions to the horrifying descriptions of the murder victim's condition). Another issue is framing, previously it was a question of 'Who committed this awful crime?' now it has been reframed as 'This awful criminal might go free.' As gwern mentioned the fact that they are foreign is a factor, local media are unlikely to be kind to them, and punishing them/avenging a local feeds into our in/outgroup biases. And finally, the large publicity of the case means that enough people have heard about it that a significant percentage of them will attach to one side of the case for some arbitrarily bizarre psychological reason of their own whatever the facts of the case.

What have I missed?