I can’t imagine how it would be possible for an unrepentant serial killer, for example, to be saved, but I wouldn’t say I know such a person won’t be saved. Only Christ knows who will be saved.
That’s the point I am making. If someone dies and we know their sin “history”, we could say with a high degree of confidence if they would be doomed eternally or not.
I don’t like to speculate about anyone’s eternal fate - that’s the Lord’s department. I don’t even like to speculate about my eternal fate (but my hope is that I will be saved).