How is conflict resolved when both parties present contradictory evidence regarding the perpetrator's mental state?

Primary text

If both parties present contradictory evidence, such as evidence stating the perpetrator was lucid (*zail al-'aql*), while the guardian claims he was drunk (*sakran*) and the killer claims he was insane (*majnunan*), the statement of the killer claiming insanity prevails, accompanied by his oath. This is because the perpetrator has superior knowledge of his own condition, and the foundational principle is the acquittal of his liability, coupled with the fact that a Muslim avoids acts forbidden to him.