Legal Question in Real Estate Law in California

"A second loan on the property" IS a lien that BofA already HAS on the property. As with any loan secured by a lien on real property, the lender has two choices if the loan payments are not made when due - go after the person who owes the debt, or foreclose on the property. If the person is dead, the lender can go after the estate of the decedent. It almost never makes any sense, however, for the lender to go after the borrower rather than foreclose. That is even more true when the borrower has died. On the other hand, if the lender has only secured the debt with a 1/2 interest in the property, when they foreclose they will become 1/2 owners with the other non-borrower owner, which is not a very desireable position to be in for a bank either. The bottom line, though, is that unless his heirs and executor choose to pay the debt, you are going to have to deal with it one way or another.

As far as "putting a lien" on the property goes, the borrowing of money using the property as collateral puts a lien on it. I'd say, therefore, that there are already two liens on this property; one created when you took out the mortgage loan and the other created when your now-deceased ex took out a second.

When only one of two joint tenants signs loan documents, only that owner's interest becomes subject to the lien of the mortgage (actually, in California, it'd probably be a deed of trust securing a promissory note, but the combination bears many of the characteristics of a mortgage and everyone calls them a mortgage). Therefore, I'd figure each mortgage is secured by a half interest, but I'd verify this as a starting point. It's somewhat unusual for a lender to loan much with only one of two co-owners signing the loan documents and becoming co-obligors. Among other things, banks are apprehensive about the possibility of a foreclosure where they can only sell a half interest in a property. There ain't no market for half interests with presumably hostile co-owners!

Now, as to who is responsible for paying his debt. When someone dies, their intensely personal oblications perish with them. Picasso's estate and heirs cannot be obliged to do a portrait despite a pre-death contract to paint it. However, ordinary obligations to pay debts stick to the estate, and need to be paid by the executor or administrator before or along with distributing net assets to the heirs. You can't inherit a $10 million castle free from the $9.5 million mortgage on it. It's up to the executor or administrator of an estate to pay its bills before distributing its assets to the heirs.

In your case, I'd say that as a first consideration you need to determine who inherited his interest in this property. If you did, that simplifies things. However, you still need to deal with paying the indebtedness (lien) he created.

You mention an ex, a death, and joint tenancy. Your divorce more than likely severed the joint tenancy. I suggest speaking at length with a competent real estate attorney to go over the particular facts in detail.