Who swears first when guardians claim a killing and there is a *Lawth* (presumption of guilt) between the claimant and the deceased?

Primary text

The oath is initiated with the claimants first. They must swear fifty oaths that the defendant committed the killing. If the claimants fail to swear, the defendant is then required to swear fifty oaths to be acquitted. This view is held by Yahya bin Sa'id, Rabi'ah, Abu al-Zanad, Malik, and Al-Shafi'i. The justification is based on the principle that the oath belongs to the defendant, as stated in the Hadith: 'But the oath is upon the defendant,' reported by Muslim, and 'The evidence is upon the claimant, and the oath is upon the defendant,' reported by Al-Shafi'i in his Musnad. Furthermore, it is an oath in a claim, thus it is incumbent upon the defendant initially, like in all other claims.