The U.S. House Committee on the Judiciary announced on Wednesday that it is reviewing Denver and Boulder’s policies, alleging that these cities, along with other sanctuary jurisdictions, are declining to cooperate with federal immigration authorities.

The committee’s chairman, Rep. Jim Jordan, R-Ohio, issued letters to the District Attorneys, sheriffs, and police chiefs of Denver and Boulder. The letters were also signed by Subcommittee on Immigration Integrity, Security and Environment chairman Rep. Tom McClintock, R-California, and Rep. Gabe Evans, the Republican representative for Colorado’s 8th Congressional District.

The letters accused Denver and Boulder officials of prioritizing “illegal and criminal aliens over American citizens,” undermining public safety and hindering “the efficient enforcement of federal law.”

Denver and Boulder are among a number of “sanctuary cities” across the country with policies limiting local law enforcement’s cooperation with federal immigration agents.

In letters to Denver and Boulder District Attorneys John Walsh and Michael Dougherty, Jordan accused the officials of giving “preferential treatment” to those living in the country illegally.

“Under your office’s pro-crime, pro-illegal immigration policies, illegal alien criminals are allowed to freely operate, terrorize local communities, and reoffend without consequences,” the letter states.

The letter noted the cities’ policies against sharing certain information with federal immigration officials and cited Dougherty’s comments suggesting that Colorado law enforcement officers restrict ICE’s access to license plate reader technology.

According to the Boulder Reporting Lab, the City of Boulder shared its automatic license plate reader data with ICE for three years but limited the practice last June after public outcry.

Denver Mayor Mike Johnston signed an executive order in February prohibiting ICE from accessing the city’s databases and technology without a subpoena, warrant, or court order.

Separate letters to the Denver and Boulder police chiefs and county sheriffs allege that the departments’ policies against holding individuals on immigration detainers have endangered their communities.

State law prohibits local law enforcement from holding individuals solely on the basis of federal immigration detainer requests.

The federal committee is requesting a number of documents related to immigration policies, including:

• Any communications related to officials’ interactions with ICE since Jan. 1, 2025
• Documents relating to the prosecution of noncitizens since Jan. 1, 2025
• The number of ICE detainers each law enforcement agency has declined
• Documents and communications related to employee trainings on the role of ICE
• Documents and communications between the District Attorneys’ offices and law enforcement officials relating to immigration enforcement

The House Judiciary Committee gave the Colorado officials until June 3 to submit all relevant documents.

The Trump administration has challenged Colorado’s immigration policies before. Last year, Denver Mayor Mike Johnston joined the mayors of Boston, Chicago, and New York City at a Congressional hearing on their cities’ immigration approaches, where he said he did not believe Denver’s detainer law needed any changes.

The U.S. Department of Justice also sued both the City of Denver and the State of Colorado over their immigration policies. A federal judge dismissed the suit in March, ruling that the federal government cannot compel state or local officials to enforce immigration laws.