Brooklyn District Attorney Eric Gonzalez, joined by New York State Attorney General Letitia James, announced filing of two separate federal lawsuits against Immigration and Customs Enforcement in September. (Photo: Mary Altaffer/AP)

New York officials' challenge to the Trump administration's policy of arresting undocumented immigrants in and around state courthouses will be allowed to proceed toward trial, under a Manhattan federal court ruling issued Thursday.

Citing "ancient" common-law protections against civil courthouse arrests, U.S. District Judge Jed Rakoff of the Southern District of New York said the lawsuit from New York Attorney General Letitia James and Brooklyn District Attorney Eric Gonzalez raised valid claims that the practice could have deleterious effects on the criminal justice system.

Rakoff said the court should hear from the public officials evidence on whether U.S. Immigration and Customs Enforcement activity in courthouses could have a chilling effect on immigrants' ability participate in the justice system and on the courts' ability to administer justice.

The 36-page opinion, issued early Thursday afternoon, rejected a motion by ICE to dismiss the suit and nixed key arguments that the federal government has exclusive authority over immigration matters.

"Courts cannot be expected to function properly if third parties (not least the executive branch of the government) feel free to disrupt the proceedings and intimidate the parties and witnesses by staging arrests for unrelated civil violations in the courthouse, on court property, or while the witnesses or parties are in transit to or from their court proceedings," Rakoff said in his ruling.

In a statement, James called the administration's policies "nothing more than illegal maneuvers that harm our state's ability to provide justice through the court system."

"Our state courts cannot function with ICE attempting to arrest parties, witnesses, and victims who rely on our courts for relief," she said. "While the president and his administration continuously look for new ways to intimidate immigrants and punish New York's sovereign status, we will continue fighting to ensure justice and public safety for all New Yorkers."

Gonzalez said Rakoff's ruling "recognized the merits," and he looked forward to "continuing litigation of this case, so this misguided practice by the federal government is halted once and for all."

The lawsuit, filed in September, targeted a 2017 executive order from the Trump administration, which formed the basis last year for an ICE directive that allowed agents to conduct civil immigration arrests on state courthouse premises.

James and Gonzalez claimed that since the policy went into effect, arrests in and around state courthouses jumped by more than 1,700%, according to one analysis by an immigrant advocacy and legal services group.

Lawyers from the U.S. Attorney's Office for the Southern District of New York moved to dismiss the suit in October, arguing that federal law passed by Congress superseded the centuries-old common-law protection. The administration's policy, they said, could not even be reviewed in federal court.

At oral arguments in November, Rakoff appeared to chafe at that notion, calling it "unusual and extraordinary." At the time, however, he said he had made "no clear determination yet" on the issues before him, and promised a ruling by year's end.

On Thursday, Rakoff said the government's position threatened to expand the agency's own authority and reshape its relationship with state governments.

"This result would be a most unusual one under our constitutional system, let alone in any nation that prides itself on adhering to the rule of law," Rakoff said.

He continued: "If the logic of defendants' arguments were carried to its extreme, ICE would become virtually a fourth branch of government, with unfettered discretion not subject to any meaningful review by any constitutional court."

The judge said that more than 500 years ago, English courts developed a common-law privilege against civil courthouse arrests that remains largely intact today.

The purpose of the protection, Rakoff said, was to ensure the ability of parties to advocate for themselves in their own civil and criminal proceedings and to serve as witnesses in others, but more importantly, to safeguard the courts from disruptions that delay the administration of justice.

"The directive undermines this purpose as well. It has caused precisely the delays, reschedulings, waste, and disruptions that so many earlier courts feared," he said. "This reason, more than any other, compels the court to find that, as a matter of New York law, aliens are privileged from immigration arrest while present at courthouses and during their necessary coming and going therefrom."

All discovery in the case was set to be completed by the end of February, with briefing to follow. Rakoff also set a hearing on summary judgment motions for April 14.

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