The aftermath of an immigration raid.

SAN MIGUEL DUEÑAS, Guatemala—One year ago, Freddy Granados said goodbye to his wife, Hilda Gil, and their two small children here in a shack tucked between volcanoes and coffee plantations. With job prospects in Dueñas grim even for Granados, a skilled baker, he departed on the standard illegal-border-crossing odyssey of poor Latin Americans chasing el sueño Americano.

Five months later, on May 12, 2008, Granados rose early and left the small apartment he shared with five other Guatemalan men to report for work on the cow-skinning line at the Agriprocessors kosher meatpacking plant in Postville, Iowa. That day, he and the 389 other illegal immigrants who arrived for the early shift fell prey to an expansive immigration crackdown, called "military-style" by a local priest. To make arrests at a plant with around 800 employees, the U.S. government dispatched 900 immigration agents and two helicopters. It was the second-largest workplace immigration raid in U.S. history, and it cost taxpayers $5.2 million, according to an October report by the Des Moines Register.

Within eight days, about 300 of the workers, including Granados, were coerced into pleading guilty to charges of identity theft and misuse of Social Security numbers, according to a court interpreter, Erik Camayd-Freixas, who penned a searing account of the trials. Granados was then sent to federal prison in Louisiana, where he served a five-month sentence before being deported back to Guatemala.

In the last two years, Immigration and Customs Enforcement, a division of the U.S. Department of Homeland Security, has begun to deploy the workplace raid with greater force. During that period, work-site enforcement arrests increased 41 percent from 3,667 to 5,173, while criminal arrests (mostly involving business owners, managers, or human-resource employees) increased 34 percent from 716 to 1,101.

But beginning with the Postville raid, ICE devised a way to use identity-theft laws to criminalize immigrants for working. Identity-theft laws are intended to prosecute people who steal identities to defraud others of money and property, not for people who use false papers to get a job. In the majority of the Postville cases, according to Camayd-Freixas, the immigrants were unaware that the Social Security number they were using belonged to a real person.

Entering the country outside the ports of entry and without proper documentation is certainly a crime, but a civil trial and quick deportation should be sufficient punishment. After months of lawyers, human-rights activists, and even some members of Congress kicking up a fuss over the application of identity-theft laws to immigrants, the Supreme Court recently agreed to hear a case on the issue.

"It's very unfair what they're doing," Granados told me over the phone recently, his voice squeezed by tears. "We're not criminals. We're workers." Granados was deported on Oct. 11, and he arrived home three days later. He says he is deeply pained by his experience and particularly by the treatment he received in the federal prison.

Granados said one of his lowest moments came when he spoke to his wife in July to tell her that he was in jail and would not be sending any more money. (According to Granados, federal prison officials did not let him communicate with his family for three months after the raid, nor did he ever receive his personal belongings from Postville.) Word of the raid had reached Dueñas, but Gil knew nothing of Granados' whereabouts and was gravely worried.

I met Gil in early October through her neighbor Mirna Jerez and a string of other women whose husbands and sons once worked in the Postville plant. In Dueñas, the summer brought a shared suffering for the women—the end of the remittances sent every 15 days from Postville. Most women had received about $265 a month from their husbands—enough to cover the electricity bill, keep an extended family nourished, and buy school supplies for the children. "These months have been very difficult," Gil, a timorous 32-year-old with a soft, round face, told me.

The women were perplexed by the charges; none of their husbands were troublemakers. They had gone to the United States for no other reason than to make life a little easier for their families in the shanties.