One does not have to single out "the Peltier case" to see that it is difficult to overturn a significant guilty court verdict. There are many people who face that same dilema, in and outside of the USA.

True but with the recent appeal Knox. I found it interesting to note that some US writers commented that she was fortunate to be in Italy rather than home in the USA.

I suspect that cases involving clear and coldly executed death (and, especially the killing of law enforcement officers), make such appeals even more difficult, in all countries. But, that should not be a surprise.

That may well be true but I hope you are not suggesting that a system that operates in such a manner can be considered just.

If a person is seen as violent (potential violence is not always seen to be mitigated by being locked up in jail), associated with other crimes, or a member of an extreme political movement, would anyone expect freedom not to be even more challenging to achieve?

Similarly I trust you are not suggesting that a wrongful conviction can possibly be justified for these reasons.