Do you think it's possible for a molester to change their ways?

I know this man who molested his siblings when he was a young adult. He has kids of his own, and grandchildren. I saw photos of him and his daughter's child, and I shuddered. I can't possibly believe that he didn't do the same to his kids, and possibly grandkids. Unfortunately, those who were victims of his terrible crimes never wanted to dig up the past and have him charged. Is it possible a monster like that could change?