AG James files amicus brief defending NYC sanctuary city laws after federal challenge

New York Attorney General Letitia James filed an amicus brief on Tuesday defending New York City’s sanctuary city laws, arguing that the laws are essential to preserve public safety and that they do not limit cooperation between local and federal authorities on criminal investigations.

The amicus brief comes after a July 2025 Department of Justice (DOJ) lawsuit against the city challenging the laws, in which the DOJ argued under the Supremacy Clause that sanctuary city laws, which limit local cooperation with Immigration and Customs Enforcement, “reflect an intentional effort to obstruct federal law enforcement.”

“New York City’s sanctuary laws help keep our communities safe,” James said in a Tuesday news release. “Our city was built by immigrants, and this administration’s attempts to overturn local laws that protect them are unjust and unconstitutional. I will always defend New York’s immigrant communities and uphold the rule of law.”

The brief supports New York City’s motion to dismiss the July 2025 DOJ lawsuit — a motion that city officials filed in September 2025.

The immigration crackdown by President Donald Trump’s administration has raised questions from lawyers regarding the legality of ICE tactics and has outraged New York electeds, including James, Mayor Zohran Mamdani, and Gov. Kathy Hochul.

In New York City, and across the country, ICE agents have worn masks while on the job to conceal their identity and have used increasingly brutal tactics to make arrests. At 26 Federal Plaza in lower Manhattan, ICE agents have arrested hundreds of immigrants arriving for routine hearings, detaining them in the same building in cramped and squalid conditions.

James argues that sanctuary city laws are key to public safety

The brief focuses on data showing that immigrants are less likely to report crimes, serve as witnesses, and “seek help without fear” when there are no sanctuary city laws limiting local collaboration with ICE. New York City’s sanctuary laws, like similar sanctuary cities across the country, do not prohibit local collaboration with ICE when it comes to criminal matters.

James also argued in the brief that sanctuary city laws are key to building trust between local law enforcement and communities.

The specific policies in question are laws that prohibit the NYPD from detaining an individual by the request of ICE “without a judicial warrant and certain other prerequisites,” from taking “direction from the U.S. Department of Homeland Security to further federal civil immigration enforcement,” and from using “city resources for federal civil immigration enforcement.”

The amicus brief comes weeks after Hochul introduced legislation to ban ICE from deputizing any local law enforcement official or department in New York State. The “Local Cops, Local Crimes Act” looks to prohibit cooperative 287(g) agreements that allow ICE to deputize local officers to act as federal agents and assist in immigration enforcement. There are at least 10 287(g) agreements in New York State — up from just one at the start of 2025.

Hochul and James have both argued that unnecessary cooperation with the federal government’s immigration enforcement diverts crucial resources from local issues.

“The city has acted lawfully—and, indeed, wisely—in directing scarce local resources to its

public safety priorities, rather than providing uncompensated support for the federal government’s civil immigration enforcement that would harm community trust and thus public safety,” the brief reads.

James argued in the brief that, while the federal government does have the power to enact laws that supersede state and local laws under the Constitution’s Supremacy Clause, there is a “strong presumption” against the clause’s execution, especially regarding a state’s “traditional police powers.”

“[S]tate and local control of state and local law enforcement resources is at the heart of federalism and should not lightly be found to be preempted,” the brief reads.

The brief comes after the DOJ indicted James in October 2025 over alleged bank fraud charges. Believed by Democrats and many attorneys to be part of Trump’s promised retribution campaign, the indictment was dismissed by a judge in November.

A grand jury twice declined to indict James, landing a blow to Trump’s efforts to take down political rivals.

James has consistently challenged efforts by the Trump administration to eliminate Temporary Protected Status for certain immigrant groups, slash Supplemental Nutrition Assistance Program benefits, and restrict medical treatment for transgender youth.

Spokespeople for DOJ did not immediately respond to a request for comment.