I don't believe the death penalty is reserved for those who only intend to take a life. Adultery and rape don't have the intention of taking away a life, but more or less using life in a perverse intent.
Here in Romans 1 (KJV)
26For this cause God gave them up unto vile affections: for even their women did change the natural use into that which is against nature:
27And likewise also the men, leaving the natural use of the woman, burned in their lust one toward another; men with men working that which is unseemly, and receiving in themselves that recompence of their error which was meet.
28And even as they did not like to retain God in their knowledge, God gave them over to a reprobate mind, to do those things which are not convenient;
29Being filled with all unrighteousness, fornication, wickedness, covetousness, maliciousness; full of envy, murder, debate, deceit, malignity; whisperers,
30Backbiters, haters of God, despiteful, proud, boasters, inventors of evil things, disobedient to parents,
31Without understanding, covenantbreakers, without natural affection, implacable, unmerciful:
32Who knowing the judgment of God, that they which commit such things are worthy of death, not only do the same, but have pleasure in them that do them.
Homosexuals are clearly described here, and their acts are "against nature." And in the bold text, you see they're even deserving of death.