The ruling on one who kills a child with his car by mistake?

The questioner:
Our sister says that this accident happened about ten years ago or more. Her brother and her father were heading to a certain place, and on the way, a child suddenly appeared in the middle of the road. Her brother could not stop the car except after the accident occurred, and the child died. The child’s father waived the case when he was paid a blood money (diyah) of thirty thousand riyals. The question is that the thirty thousand was not from her brother, but rather her husband and relatives gathered it for him because he did not have any money. Is this blood money valid? Or must he gather thirty thousand from his own money without anyone’s help? And does fasting for two months or freeing a slave suffice as the expiation? May Allah reward you for your help. Matters like this should be referred to the Shari'ah courts to look into the causes of the situation and whether your brother was the cause.

The Shaykh:
In the death of the child, and he bears responsibility.

The presenter:
Yes, it is necessary to return to the court.

The Shaykh:
It is necessary to return to the Shari'ah court if there is a Shari'ah court in your country. If there is no Shari'ah court, then they look into whether your brother was the cause and whether he was negligent at the time of the accident. If so, the expiation is upon him. The expiation is freeing a slave, and if he cannot, he fasts for two consecutive months.

The presenter:
As for the blood money.

The Shaykh:
This is the blood money for an accidental killing, and it is upon his heirs, and they are his 'asabah (residuary male heirs). Yes, they bear the blood money.