it’s still stopping the existence of an organism and preventing a human life from happening after it already started to happen.

That part I highlighted is a subject of debate, and since it hinges on opinions about the definitions of words rather than anything with a clear-cut objective measure it’s a debate that’s not going to be settled any time soon.

I meant your usual death row guy who viscously killed/etc multiple people in a horrifying way

What a good thing that the state never, ever incorrectly convicts people of having done those things.