First of all I perhaps should have said remorse and contrition rather than just remorse.
Second,two criminals were crucified with Christ.One taunted Christ,asking Him why he couldn't save Himself.The other asked Christ to remember him as He entered the Kingdom of Heaven.
To *that* criminal Christ said "Amen I say to you today you will be in paradise"
Christ understood that the "good thief" had true remorse and contrition for whatever sins he had committed.
Although I suspect that you're correct to observe that sinners aren't *automatically* forgiven and also acknowledging that this *particular* guy may not have had true contrition I'll bet that there are at least some who are guilty of serious sin who've had their sins forgiven by God.
I think it must be even be considered possible that *Hitler* is in Heaven now....although I can't see him being capable of true remorse or contrition.But we cannot be 100% certain of that...only God knows the true contents of a person's mind and heart.
If Hitler isn't headed for hell then there is no hell!!!!!