Truth Commissions and Determinism

It seems the arguments in favor of torture have all been exhausted and shown as not only immoral, but impractical. The new arguments concern truth commissions and their validity and practicality. Do truth commissions bring about justice for crimes against humanity? Is amnesty in exchange for truth worth letting the criminal go?
In class, there have been several allusions to studies showing that amnesty helps the victims of the crime more than simply punishing the criminal. I’ve never read these studies, but am willing to take Dr. Johnson’s word for it. What interests me about the argument for truth rather than punishment is how it works into determinism. If determinism is granted as true, then there can be no culpability, and thus no moral grounds on which to blame the criminals. Punishment under determinism is ungrounded, so it seems like gaining the truth in order to help the victims is obviously a better option. The criminal is not punished for something that was going to happen anyway, and those affected by the crime will supposedly be better off.
Trying to fit justice into determinism is very difficult, but in the case of truth commissions, it seems to fit quite nicely at times. When considering egregious crimes against humanity, it is hard to settle on what the best punishment or retribution for the crime should be. The people affected should be compensated for their loss somehow, and it should also be demonstrated that we, as humans, will not accept the occurrence of these crimes. It makes sense to allow for the criminals to gain amnesty for the truth if that is what brings about the best for the victims and for world knowledge. In a sense, this is a utilitarian idea, for it brings about the most pleasure for the most people. This can also work with determinism because we are declaring that these actions are indeed wrong, but not enforcing culpability onto the individual. Obviously, truth commissions do hold those that committed the crimes responsible for their actions, but by granting amnesty they do not act on this culpability.
I realize when writing this that I’m using moral grounds to defend amnesty in exchange for truth, all the while, toting determinism, but in the scope of this argument I believe it is acceptable. I am merely trying to argue that certain aspects of truth commissions can be accepted by determinism.