Smith Frozen Foods' hiring of illegal immigrants emerged as a major theme in the first debate between U.S. Sen. Gordon Smith (R-Ore.) and his Democratic challenger, Jeff Merkley.

After a member of the debate panel last week on KGW Channel 8 referenced WW's three-part investigation of Smith's employment practices, Smith responded, "All of our workers are documented."

Meanwhile, WW returned last week to Eastern Washington to speak with another former Smith Frozen Foods worker who got a job at the senator's factory on the Oregon side of the Columbia with a fake Social Security number.

But in this case, the worker—who asked to be identified only by her last name—offered written evidence (this June 2003 letter WW has redacted) that Smith Frozen Foods would have had reason to believe she was illegal when the plant was under Smith's direct control. But the senator maintains all his workers are documented and are fired when evidence to the contrary comes up. Yet red flags, like this letter, add to the growing body of evidence that not all the employee documents are valid.