The only chance for 'forgiveness' anyone should get is the chance to apologize to the people they've hurt. If their victim dies, there is no way to ever earn forgiveness. The only person who could possibly forgive them is gone.

In effect, I owe someone I've hurt an apology. They owe me nothing.

How do their victims feel about it?
That was rhetorical since they're still dead and can't be released from it

If they had killed your parents would they deserve forgiveness? if they killed your husband or boyfriend would they deserve forgiveness?
if by chance for forgiveness you mean let out of prison, the answer should be no. Are you to be the arbitor of genuineness? Who decides genuineness? What prisoner wouldn't say they were sorry if they had the chance to get out? How about this one, what if they killed you and did horrible things to your body? Should your family just forgive them and let them out? They're REALLY sorry.
p.s. if it makes you feel good, just forgive all prisoners in our country, I'm sure it'll mean a great deal to them. But they stay where they are.
p.p.s. why do I get the sense that you've never been the victim of a crime?

Trouble is many people who commit crimes can be very manipulative and devious so you can't be sure . I generally leave it to karma unless they threaten me

Forgiveness is a personal outcome and so only the individual knows that.

From a criminal justice viewpoint retributive justice rarely yields good results for society relying on the biblical eye for an eye process.

Rehabilitation should always be a consideration. Sentencing is another matter.

It’s not my job to either judge or pardon and I don’t care if someone feels remorse or not. Guilt is an irrational emotion. Better than to feel remorse would be to recognize an action as a mistake.

If I have bad feelings toward someone it is in my best interest to forgive so that I can be relieved of those destructive unhappy thoughts. It is a private matter—I must realize that I was mistaken in my previous judgment and come to see the other person as a beautiful, miraculous fellow human, and that their mistaken actions have not diminished their true self. It would be easier just to not make judgments in the first place if possible.

If something or someone is a danger, then that danger has to be dealt with, but that has nothing to do with judgment or forgiveness.

Perhaps if you were the victim and you found it possible to forgive. But if you're not the victim then it's not up to you. And just because they might be forgiven doesn' t mean they shouldn't spend their lives in prison. I might forgive a dog for biting my child, but I'd still shoot it. In the case of people, punishment serves several purposes and one of them is to discourage others, so they need to be seen to serve their sentences.

That is the retribution vs. rehabilitation issue.