I think this must be very tough on his parents. They must have, and will still be, going through hell. They have lost their DIL and their baby granddaughter - and now their son, in a different way.
They have heard his story so much over the months no doubt. He is their son; they will want to believe he is not capable of this. They will look for anything, no matter how small and flimy it may seem to others, to prove he is innocent. Their son has tolf them he is innocent, and right now they probably have to hold that to them. To accept he is guitlty in effects means giving up their son as they know him. How difficult must that be, one can only guess.
However I suspect now he has been found guilty, arrticulalryly if this goes to appeal and he is still found guilty (as it very very likely), in time they will realise it to. They must begin a form of grieving for their son - or rather for the man they believed him to be. One of the first stafges of the grieving process is denial - I suspect they will remain in this phase for a while yet. It will be a long process for them.
This man after all is still their son, their child. They didn't deserve to be put in this position, and they will have no reference on which to call to know what they should do or how they should act. I think they should be allowed to go through this process in peace.