The families’ federal lawsuit challenges how immigration enforcement was carried out during an FBI-linked operation at La Catedral, a privately owned race track about an hour west of Boise, and centers on what they describe as coercive tactics and discriminatory decision-making.

According to the lawsuit described by the American Civil Liberties Union of Idaho, the October raid involved roughly 400 people detained for hours at the privately owned track while a federal investigation pursued allegations of illegal gambling. The families say that, despite a criminal search warrant connected to the gambling inquiry, the operation functioned as “essentially a ‘fishing expedition for immigration violations,’” in the words of attorneys with the ACLU of Idaho. They also said only five people at the event were arrested in connection with the gambling investigation, while more than 100 others were arrested on suspicion of immigration violations.

The track event was described as family-oriented for the local Latino community, with food vendors and games for children. The lawsuit says that on Oct. 19, about 200 law enforcement officers flooded the property wearing militarized gear and face coverings, with officers pointing guns and screaming orders at families, according to the ACLU’s account.

Nampa Mayor Rick Hogaboam, who said the city takes the matter seriously and is committed to following the legal process with integrity and professionalism, was quoted as part of the response to the allegations. The city and the Nampa Police Chief are named as defendants in the lawsuit, while the FBI and the Canyon County Sheriff’s Office declined to comment and other defendants did not immediately respond to requests for comment.

ACLU attorney Jenn Rolnick Borchetta said officers used racial epithets for Latinos and used more force against people perceived to be Latino than against detainees who appeared to be white. She also described conditions including detainees left in zip ties so tightly they suffered injuries and people denied bathroom access. Borchetta said she had “never seen so much direct evidence of racial targeting, and ethnic targeting, as I have in this case,” during a news conference about the case.

The lawsuit also says children were among those detained and restrained. Families later told The Associated Press that children as young as 11 were restrained, and that children were separated from family members for hours. One of the lead plaintiffs, Juana Rodriguez, was quoted as saying in October that her hands were zip-tied for almost four hours, leaving her unable to pick up and care for her 3-year-old son.

The families said they were released after proving citizenship or lawful permanent residency, and they asked for the case to be certified as a class action. They seek a federal judge’s declaration that law enforcement violated federal law and detainees’ constitutional rights and seek damages in an amount to be determined at trial.

Homeland Security Department spokeswoman Tricia McLaughlin said afterward that ICE “dismantled an illegal horse-racing, animal fighting, and a gambling enterprise operation.” The lawsuit described in the reporting said court documents make no mention of animal fighting and that the track had a horse-racing license. McLaughlin later added that ICE did not restrain or arrest children.

The lawsuit invokes the Fourth Amendment’s limits on unreasonable searches and seizures and the 14th Amendment’s guarantee of equal protection, along with federal civil-rights statutes. It cites Section 1983 as allowing individuals to sue state and local government employees for civil-rights violations, and it cites Sections 1985 and 1986 related to conspiracies to interfere with civil rights.

In remarks tied to the lawsuit, Paul Carlos Southwick, the ACLU of Idaho’s legal director, said: “I want to be clear about what this was: A coordinated government scheme to weaponize an arrest warrant as cover for racial profiling on a massive scale.” He added that the “real objective was to deport hundreds of innocent people, no matter the human cost, while spreading terror throughout the Latine community.”

The broader legal backdrop cited in the reporting includes court decisions addressing when immigration officers may stop people for questioning. The reporting said a federal judge in California had issued a restraining order barring immigration agents from stopping people solely based on their race, language, job or location, but the Supreme Court lifted that order in a 6-3 ruling in September; Justice Brett Kavanaugh wrote separately, according to the reporting, and suggested that judicial second-guessing of how officers carry out brief stops for questioning could chill lawful enforcement, though he also indicated that stops using force could still face legal challenges.