He wasn't on Facebook to begin with and usually dead people don't Facebook pages. Getting in contact was difficult as his wife had "disappeared." I figured she had married again, but not having new last name makes it difficult.
I searched facebook for his children, using the name of the most unusual child. She didn't have "relatives" listed but I recognized one of her "friends" as one of her siblings. That sibling's Facebook page had his mother listed. I knew I had the right person as the first name was a match--but the last name was different.
Sometimes you have to creep on Facebook ;-)