In the sad case of relatives and friends who have died there are two options,
It is Facebook's policy to memorialize the account of a deceased person.
To report a timeline to be memorialized, you can fill out a ‘Memorialization Request’.
Delete The Account
Verified immediate family members can request the removal of a loved one's account.
This involves filling out a ‘Special request for a medically incapacitated or deceased person's account’ form.