What must a father do to atone for accidentally killing his daughter with a legally owned weapon?

If a person accidentally fires a bullet and it hits his daughter, causing her death, this is considered an accidental killing (qatl khata'), for which there is no sin. However, it necessitates two things: blood money (diyah) and expiation (kaffarah).

The blood money is to be paid by the killer's 'aqilah (his male paternal relatives) and given to the heirs of the deceased. The killer himself does not inherit any part of it, and it can be waived by the heirs.

The expiation is the freeing of a believing slave. If one cannot be found, then it is fasting for two consecutive months.

If the 'aqilah are unable to pay, the responsibility falls upon the Muslim treasury (Bayt al-Mal). In the event that it cannot be obtained from the Bayt al-Mal, there is a difference of opinion among jurists: some hold that it is waived for the killer, while others maintain that it becomes obligatory upon the killer himself.