Is it permissible to kill the person who raped the girl one wishes to marry?

The blood of a Muslim is not a trivial matter. Intentionally killing a believer is punishable by Hell, Allah's wrath, His curse, and a great torment. A Muslim's wrongdoing and committing forbidden acts do not justify killing him, for his blood is sacred like that of other Muslims. The implementation of hudud (punishments) is entrusted to the Muslim ruler, represented by the judiciary.