He can be forgiven if he truly repents, and is not the same person anymore turning from sins, but the thing is people who are that bad to do such things do many of them change.
The Bible says many are called but few are chosen, but not many wise men after the flesh, not many mighty, not many noble, are called, because not many of them have the heart condition to be called because they like to exalt themselves so much above people, and are arrogant.
People that would do terrible things such as this man would many of them change, for many people that live for God had minor sins in their life, and were not that terrible, although they still needed to be saved, and turn from what little sins they did.
Paul said that he went against the Church, and wasted it, and consented to put to death the Christians, but Jesus got a hold of him, and Saul followed him, and his name was changed to Paul to identify his new character.
Paul was forgiven for his sins, but Paul also was not a typical person that did a terrible thing, and was saved, for Paul was living for God already, and said that he was a Pharisee of the Pharisees, more jealous of the traditions of his fathers, but he did not accept the truth of Jesus, and thought he was doing the will of God.
So when Jesus got a hold of him, he turned quickly to the Lord, for he knew that it had to be God he encountered on the road to Damascus, and found out it is Jesus, so he straightway followed the Lord, for he was already living for God, and could turn quick to the truth, for he could not deny that it was God he encountered, who is Jesus.
But many people that do terrible things such as this man, would they change, which they could change, but it would probably be few unless they have a Damascus road experience like Paul, which they will not get, for Paul was reaching out to the Gentiles so he had to have proof that Jesus is real so he could go without doubting that it is true, and the same with the disciples, but to the rest of the people it is faith, which is why Jesus said blessed is he that has not seen Me, but still believes.
The majority of people that were saved did not really have too bad of a life concerning sins, for they were minor, and few, and they were basically kind of good, and that towards people, which is why they were called, but people that do terrible things would seem like a few of them would be saved, for many of them might not change, although they could change, and be saved.
For when we are truly saved God gives us power, love, and a sound mind, so if they truly repent, and mean it, and receive the Spirit, then their mindset is different, especially when God gives us a sound mind, and they also value human life that they are God's creation, and do not offend them in any way.
It does make us doubt, not that they cannot be forgiven, but would they actually change, for they have to change first before they can be forgiven, for saying I repent of this stealing incident, but holding unto the sin that you would steal again, is not truly repenting, for you are only repenting when you do the act, but holding unto the sin that you might do it again.
He has to know that he will never do it again, and know why it is wrong, and believe it, before he can be forgiven, and have a relationship with God, for we cannot doubt that we may do it again, but we have to know we will never do it again, and know that it is wrong, and not want sins, and hate sins.
We also doubt because we think that so many that go to prison, and say they found God have an angle, an agenda for their own benefit, and not really caring about the truth, and people in prison do not like when you mess with children to harm them, so big Bubba will surely get him, which I do not say that I want that to happen, but he will have trouble.
But he did such a terrible crime that he cannot get a reduced sentence, and he might think it will keep the inmates from harming him if he claims he found God, and is a different man.
He can be forgiven, but there is doubt that he will change, but he can change.