Indexing proper names

I need to create an index from a facebook—a book of photos with names and some basic details for each person. I am using a paragraph style for the name and hometown that uses a nested style to change the font after a forced line break (hometown on second line). Is there a way to automate the indexing using the paragraph style (or any other way) to select all the names in the entire book (there are hundreds of them) and create index entries (last name, first name)? A GREP search & replace? Script? The index will be Last Name, First Name, page number only. No categories or subcategories. I can't be the first person who has had to do this.