I expect to be also. I also expect to be forgiven. So we have that in common, I am sure. Perhaps those who ignored the Khmer Rouge are equally culpable. If these guys are sincere in their repentance (and i bet some are) who are we to stand between them and their forgiveness?
Their "forgiveness" has two parts. The one having to do with God has nothing to do with you or me. But who are we to decide if they ought be "forgiven" as you and I have not been murdered, had our family murdered, had our children murdered. I don't think we have anything to do with whether those dead people forgive or not, they are dead.
Are you suggesting earthly justice ought to be waived because you see them as forgiven?