Can a Murderer Ever Be Redeemed?

So, a person that killed, right, and is supposed to be killed for his crime, if he does chuvah, he still has to be killed because the court cannot exonerate someone who does chuvah. Chuvah is something that's between him and God. It's in his heart. We don't know that he did chuvah or not. But, I would suggest this. It's only a suggestion, food for thought. Since ultimately a person can rectify even the sin of murder, so if we can find a legal way to spare him being killed, then he can he still has time to fix his sin in a much softer way.