death
Wake them up and ask them!
No, DNA can be taken from deceased persons.
Marriage is a contract. A deceased person does not have the legal capacity to willingly enter into any contracts.
yes the funeral home usually does a deceased persons nails,and hair and general grooming to get them ready for their "showing"
Forensic Anthropology
It sounds as if you're not legally responsible for the deceased client.
Your local police department
Not unless they were guarantors of the debt.
If they have the letter of authority, yes.
Yes
If the person is deceased, you can contact the trustee if you know who the trustee is.