What is the legal consequence for a non-ruler executing an apostate?

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If someone other than the Imam executes the apostate, he has acted improperly (*asa'a*), but no financial guarantee (*daman*) is incumbent upon him, because the executed person was not legally inviolable (*mahall ghayr ma'sum*). This applies whether the execution occurred before or after seeking repentance (*istitaabah*). The executor is subject to discretionary punishment (*ta'zeer*) for his transgression and presumption of authority.