Adultery was never a capital punishment here.
Ancient Israel was in another dispensation also, they lived by the law—they were commanded to. We are in the current age of grace, totally different set of rules.
I still believe we should execute murderers, rapists, child-molesters, and those with mob ties.
See #11 for what we are commanded to do.
And God says through His inspired apostle Paul in Romans 13:3 and 4 in the New Testament that the law should execute criminals. How anyone could read this passage and not understand that God expects capital punishment for criminals is breathtakingly strange.