And yet, there are actual murderers who do receive parole - and that's the way it should be. Many countries do not even have life in prison without parole, as they rightfully recognize it as inhumane.
Why should it be that way? Did the murderer's victim(s) receive some kind of leniency or reprieve after a period of time? Did they re-animate?
I don't have a strong opinion here either way, but separating convicted murderers (especially first-degree or conspiracy-to) from free society doesn't inherently sound like a crazy bad idea.
That depends on whether you view prison as a way of getting revenge on criminals or as a way of trying to reform them.
If you view prison as an agency of revenge on wrongdoers then, of course, life without parole for murderers makes perfect sense.
If, on the other hand, you view prison as a way of trying to reform wrongdoers and turn them into productive members of society then life without parole makes no sense at all.
view prison as a way of getting revenge on criminals or as a way of trying to reform them
This is the crux of the whole issue. The US is split between the two notions of justice: retribution and rehabilitation. The split seems to largely fall along political lines, which means the argument isn't likely to be settled any time soon.
I tend to fall in the rehabilitation camp but I can see some of the logic behind the other side. At the very least, I recognize that it's better for the state to apply measured retribution than for families to pronounce blood feuds upon one another. Beyond that, I'm at a loss for what to do about cold, psychopathic individuals who seem utterly incapable of reform.
Deterrence and retribution are different things. Prison systems with harsh sentences are typically more about sending a message to potential criminals than punishing existing ones.
The threat of life in prison can also be viewed as a deterrent. How long should a murderer get to be reformed? What is long enough so a person will not think that that amount of time is a good trade off to kill someone?
Someone can agree with both of your views depending on the crime. Physically harming another person, particularly irreparably is different than stealing something for example.
Why do you confuse "rehabilitation" with "acting"?
If a patient goes to a doctor and their wound heals, is that "acting healthy"?
You can make a case that we can't know if someone is rehabilitated, but if you think rehabilitation can be a thing, that necessarily includes being able to distinguish acting from genuine change.
I don't believe you can distinguish the two, especially when someone takes a deliberate and motivated action which they can fully expect to land them in prison. (See: organized crime.)
I don't have a strong opinion here either way, but separating convicted murderers (especially first-degree or conspiracy-to) from free society doesn't inherently sound like a crazy bad idea.