why shouldn't they be allowed to speak publically? They clearly believe their son is innocent as much as we/the legal system believe he is guilty. Just because he has been found guilty, doesn't mean that his parents have to give up all hope that he isn't?
Miscarriages of justice do occur after all, and while I do not for one second believe that this is one, if they believe that strongly that he is innocent, surely for them, the only way of getting justice for him is to continue to speak out in the hope that his conviction will be overturned on appeal, and and that they will not have to face up to the fact that their son is capable of such a horrific crime.
For those hearing about this case in the news, it's easy to make judgements on what we know about this man, because the only things we know about him relate to the horrendous crime he has committed. But for his parents who gave birth to him, brought him up, knew the person before the crime, there is so much more than a monster. It surely can't be that simple to discount all the good things, to forget about all those and just remember him for the crime he has committed?