Whose testimony prevails if an assailant claims the victim was a slave, or that a specific body part was missing or disabled prior to the injury?

Primary text

When an assailant claims the slain person was a slave, or that a part struck, such as a wrapped object, was missing, or that a wall fell upon the victim, or claims the victim was already dead, and the guardian denies this, the statement of the guardian, accompanied by an oath, prevails. This is one ruling held by Al-Shafi'i. The fundamental principle is the continued life and freedom of the victim, thus requiring judgment based on their continued existence, similar to cases where one claims a murdered Muslim had apostatized before the killing.