The NY Times has a fascinating story about a debt collection firm in MN that calls the relatives of deceased people asking for money on old debts.
This is horrible. It is an outrage. There is no good reason for the debt collector to call the loved ones of the deceased except one: to make money. This is the worst of the worst. The conduct is just simply despicable.
In California, you are not responsible for the debts of the deceased. The estate for the deceased is responsible. You should not pay money to a debt collector for a debt that is not yours.