[Unique427]

Not from AZ but none the less, sounds like a proof of ownership issue to resolve.

You need:
1) Copy of Death Certificate (identifying spouse if any).

If owner died Interstate (without a will)
1) Letter from probate judge naming Administrator of Estate
2) "Release of all Liens" from Administrator of Estate

If owner died with a Will:
1) Get a letter from Probate Court showing proof of appointment of Executor of the Will.
2) Get a "Release of all Liens" from Executor of Will.

Reasons for the above is for protection against any claim of ownership
or liens after your purchase. Bill-Of-Sale only is insufficient proof.

Also, it is possible DMV may require you to purchase a surety bond protecting
AZ against any claim/dispute in ownership of untitled car when titled in your name by DMV.