If the parents were together enough to leave pointers to the documents, I agree that there probably is a will. Your SO should be able to find out the name of the lawyer who drafted it. That would be a good place to start when looking for a lawyer to handle things, since the parents trusted him or her at least.
The will should have language dealing with the case where the couple die very close to one another in time, which avoids double probate.
In some states trusts are very common (like California) . Ours names an executor. If there is one, the list of documents should point to it.
I just spoke to my SO. The last couple of days have been a whirlwind of meetings with probate lawyers, insurance people, etc. The parents’ house and the one his brother was living in were both in the parents’ names, and both houses are mortgaged so far beyond their value the lawyers and creditors agreed to just let them go into foreclosure and call it a wash. (I hope that makes some kind of sense, being a half-assed attempt to relay what my SO told me; I don’t know about such things).
The good news is there’s enough life insurance to pay off the credit cards that had my SO’s name attached, as well as recoup some of the money he lent them and help his brother get a new house.
With regard to the suit, he told me to either check it or stuff it in the overhead bin, and if need be we’ll get it pressed before the memorial.