NPR spent the past several months analyzing hundreds of pages of campaign finance reports, lobbying documents and corporate records. What they show is a quiet, behind-the-scenes effort to help draft and pass Arizona Senate Bill 1070 by an industry that stands to benefit from it: the private prison industry.

The law could send hundreds of thousands of illegal immigrants to prison in a way never done before. And it could mean hundreds of millions of dollars in profits to private prison companies responsible for housing them.