ACLU attorneys representing the United Farm Workers and five Kern County residents have sued the head of the Department of Homeland Security and U.S. Border Patrol officials, alleging the Border Patrol’s three-day raid in the southern San Joaquin Valley in early January amounted to a “fishing expedition” that indiscriminately targeted people of color who appeared to be farmworkers or day laborers.

The complaint, filed Wednesday in federal court in the Eastern District of California, alleges that agents from the Border Patrol’s El Centro sector violated protections afforded by federal law and the U.S. Constitution when they rounded up and deported scores of laborers in the country without legal authorization. It seeks class-action relief for everyone subjected to the tactics, which the lawsuit describes as “lawless sweeps, indiscriminate arrests, and coercive expulsions.”

“It’s clear that this was a coordinated operation intended to sweep up as many people as possible, not based on any individualized reason, but based on their apparent race, ethnicity or occupation; arrest them and expel as many of them from the country as possible, regardless of whether they knew their rights or the consequences,” said Bree Bernwanger, an attorney with the ACLU of Northern California, one of three ACLU affiliates representing plaintiffs in the case.

Asked to comment on the allegations, a spokesperson for the Department of Homeland Security said Border Patrol enforcement actions are “highly targeted.” Any alleged or potential misconduct by agents would be referred for investigation, the agency said.

A spokesperson for the Border Patrol’s El Centro sector said the agency does not comment on pending litigation.

The El Centro sector — headquartered more than 300 miles from Kern County’s sprawling farm fields and orchards — led the unusual January raid at the tail end of the Biden administration. Chief Agent Gregory Bovino, a 25-plus-year veteran who leads the Imperial County unit, headed up the operation without the involvement of U.S. Immigration and Customs Enforcement. He is named as a defendant in the lawsuit.

Three former Biden administration officials, who requested anonymity because they were not authorized to share operational details, told The Times that Bovino “went rogue” with the January raid. No higher-ups knew about the operation before watching it unspool in real time, two of the former officials said.

In official statements, Bovino has justified the raid by noting that the sector’s area of responsibility stretches from the border to the Oregon line, “as mission and threat dictates.” Border Patrol officials have said the raid, dubbed Operation Return to Sender, resulted in the arrests of 78 immigrants in the country illegally, including a child rapist. The agency has not specified how many of the immigrants detained had criminal records.

Advocates on the scene, meanwhile, said the operation indiscriminately targeted Latino farmworkers commuting from the fields along California Route 99 and day laborers soliciting work in the parking lots of big box stores. They estimate close to 200 people were detained.

According to the legal complaint, agents swarmed businesses where farmworkers and day laborers gather, and pulled over vehicles in predominantly Latino neighborhoods, targeting people of color and questioning them about their immigration status. The complaint accuses Border Patrol agents of employing multiple unlawful practices. Among them: detaining people without reasonable suspicion that they were in the country unlawfully, in violation of the 4th Amendment’s prohibitions on unreasonable searches and seizures.

If people declined to answer questions about their immigration status, according to the complaint, agents conducted searches without warrants or consent. In some cases, the complaint alleges, when people who had been pulled over in their cars declined to answer questions, agents responded by “smashing the car’s windows, slashing the car’s tires, and/or ordering or physically pulling people out of vehicles and handcuffing them.”

At the time of the raid, the U.S. Border Patrol said Operation Return to Sender “focused on interdicting those who have broken U.S. federal law, trafficking of dangerous substances, non-citizen criminals, and disrupting the transportation routes used by Transnational Criminal Organizations.”

Instead, according to the complaint, the operation swept up people with pending immigration applications, no criminal histories and established homes in the community. Many of those deported left behind spouses and U.S.-born children, advocates told The Times.

Under federal law, an immigration enforcement officer may, without a warrant, interrogate people about their right to be in the country, as long as people are not involuntarily detained for questioning. More intrusive encounters require reasonable suspicion that a crime is afoot, according to the Congressional Research Service.

The lawsuit offers multiple examples of people it contends were treated unlawfully during the January raid.

Wilder Munguia Esquivel, a 38-year-old Bakersfield resident who works as a day laborer and handyman, was standing outside Home Depot on Jan. 7 when agents in unmarked cars arrived, demanding to see people’s immigration papers, according to the complaint.

When Munguia Esquivel backed away, the complaint says, he was handcuffed and agents rifled through his wallet.

“At no point did the Border Patrol agent identify himself, explain to Mr. Munguia Esquivel why he had stopped him, explain why he had arrested him, or produce a warrant,” the complaint says. “At no point did he ask Mr. Munguia Esquivel about his family, employment or community ties, or undertake any evaluation of whether he posed a flight risk.”

Munguia Esquivel, a plaintiff in the lawsuit, was transported to El Centro and eventually released, according to the complaint.

But scores of other laborers detained in the raid were transported to the El Centro Station for processing, then pressured to sign voluntary deportation agreements, according to the complaint.

Agents coerced people into signing the agreements, the lawsuit says, by detaining them in holding cells without access to sleeping quarters, showers, hygiene products or sufficient food and denying them communication with attorneys or family members. It says agents directed people to sign their names on an electronic screen without informing them of their 5th Amendment right to an immigration hearing. They received a copy of the form they had signed only after they had been expelled to Mexico, it says.

At least 40 of the people arrested were expelled across the border after accepting voluntary departure, the complaint says.

President Trump ran for office promising the largest deportation effort in U.S. history, initially focusing his rhetoric on tracking down undocumented immigrants who have been accused of violent crimes. His administration now says it considers all immigrants in the U.S. without legal authorization to be criminals, because they have violated immigration laws.

The complaint asks the court to compel the Border Patrol and its parent agencies, the Department of Homeland Security and U.S. Customs and Border Protection, to conduct operations in compliance with the Constitution and federal statutes.

“Without court intervention, we have every reason to expect that Operation Return to Sender was just the first example of what we will continue to see from Border Patrol,” Bernwanger said.

This article is part of The Times’ equity reporting initiative, funded by the James Irvine Foundation, exploring the challenges facing low-income workers and the efforts being made to address California’s economic divide.