The roundup of undocumented workers in Utah included 154 people who were employed by the Swift plant in Hyrum. Of those, about 40 were later charged with identity theft-related crimes.

But to find those workers, agents with U.S. Immigration and Customs Enforcement (ICE) detained everyone in the plant.

That is a constitutional no-no, argues Peter Schey, who heads the Center for Human Rights and Constitutional Law.

"Law enforcement agencies in this country are not permitted to detain the innocent in order to find a handful of guilty people," he said, citing the Fourth Amendment prohibiting unlawful search and seizure.

Schey is the lead attorney on the suit, which does not involve the plant in Utah because its workers were not represented by the United Food and Commercial Workers International Union. However, Schey is pushing to make the case a class action representing all workers involved in an immigration workplace raid.

ICE spokesman Marc Raimondi said the agency's attorneys have not yet reviewed the lawsuit but he did say the raids "were conducted lawfully and in full accordance with ICE processes and procedures."

He also said every person involved "was treated with respect."

Four employees countered that Wednesday during a press conference at the National Press Club called by the union.

Pasqual Talamentes was born in the United States but grew up in Mexico. He works for a plant in Nebraska. He said agents called him a liar, told him he was going to jail and handcuffed him.

Talamentes was later released, but is still angry at the agent who interrogated him.

"He had no idea what he was doing to people," Talamentes said through an interpreter. He said he was humiliated and hurt by an agent who acted unprofessionally.

The six-state raids resulted in the arrest of nearly 1,300 people for being in the country illegally, and Schey said the union is not trying to stop ICE from finding and deporting undocumented workers.

Instead, they are seeking a permanent injunction of "mass, randomized group detention . . . without reasonable suspicion that they did anything wrong," he said. "In this case they detained first and investigated second."

The suit, filed in Texas, also alleges ICE refused to provide workers with food and water, stopped people from using the phone, contacting an attorney or using a restroom.

mcanham@sltrib.com