As Denver Mayor Mike Johnston prepares to testify in Congress on March 5, many in Colorado and beyond are wondering just what the laws say about how state and local officials are to interact with the federal government on the enforcement of immigration laws.

On Jan. 27, Johnston was sent a letter by the U.S House Committee on Oversight and Government Reform, stating that “Sanctuary jurisdictions and their misguided and obstructionist policies hinder the ability of federal law enforcement officers to effectuate safe arrests and remove dangerous criminals from American communities, making Americans less safe.”

The letter goes on to request Johnston’s in-person testimony and the turning over of documents and communications from Jan. 1, 2024, to the present day, related to the city’s alleged sanctuary status.

Since late 2023, Denver has spent more than $350 million on migrant services, as the city received and helped resettle more than 40,000 people from the southern border.

“We didn’t choose this outcome,” Johnston said, “When the governor of Texas decided to send 40,000 people on buses to Denver, we made sure we were going to serve them.”

While the city does not explicitly use the term “sanctuary” in any ordinances or proclamations, in 2017, the Denver City Council adopted its “Public Safety Enforcement Priorities Act.” It stipulates that no department or employee of the city “shall use any city funds or resources to assist in the enforcement of federal immigration laws.” It states that city contracts related to enforcement of federal immigration laws are prohibited and the ordinance limits access to secure areas of city and county jails, “unless federal immigration authorities present a warrant issued by a federal judge or magistrate.”

In an interview with CBS News Colorado, Johnston said, “What that means for Denver is we do not ask someone’s immigration status. We don’t know your status, so we don’t share your status with other federal agencies. However, if the federal government, like U.S. Immigration and Customs Enforcement, identifies someone in our jails and wants to deport them or take action when they’re released, we notify them when the person is being released, and they can pick them up at that point.” 

During the enforcement action on Feb. 5 at Cedar Run Apartments in Denver, Acting Director for ICE Caleb Vitello said, “Unfortunately we have to come to the communities because we don’t get the cooperation that we need from the jails. It would be so much easier and so much safer for our officers and agents if we can take these people into custody from a safe environment but if we have to come out into the community to do this, that’s what we’re gonna do.”

Johnston said that ICE did not contact the city ahead of the Feb. 5 raid at Cedar Run.

“Denver police and city authorities were not involved in these actions, nor were we given prior notice,” said Johnston. “But if they do send notice requests to the jail, we respond, and we’ve had a few over the last few weeks.”

A city statement published last month holds that “Denver has always given ICE officials a heads up if someone wanted for deportation proceedings is in their custody and told them the date and time of the person’s release…We are not opposed to the deportation of violent criminals who do not have a legal status to remain in the United States, but Coloradans must prepare for the possibility that ICE agents will be detaining fathers and mothers with no criminal history.”

It goes on to say that Denver police “will not detain people for ICE and will not support non-criminal immigration enforcement actions.”

In 2019, the Colorado legislature passed HB19-1124 to “Protect Colorado Residents From Federal Government Overreach.” The law allows local law enforcement to cooperate with federal immigration enforcement authorities in the execution of a warrant signed by a federal judge but prohibits law enforcement from arresting or detaining an individual solely on the basis of a civil immigration detainer.

A bill under consideration now by the legislature, SB25-047 seeks to reverse measures that limit enforcement of federal immigration law. “2547 helps ensure that criminals in Colorado who are unlawfully in the United States are turned over, or at least their presence alerted to federal immigration authorities,” said Sheriff Darren Weekly of Douglas County.

Douglas County filed a lawsuit in April 2024 challenging HB19-1124, as well as HB23-1100 which restricts state and local governments from participating in civil immigration detention. Other counties joining the suit included El Paso, Elbert, Garfield, Mesa and Rio Blanco.

In December 2024, a Denver district judge agreed with a state motion to dismiss the Douglas County claim, holding that Douglas County has not suffered injury and does not have standing. Douglas County is appealing the ruling.

“We want to be very, very clear. We support legal immigration. We don’t support illegal immigration,” said Commissioner and Board Chair Abe Laydon. “These laws prevent local governments from working with ICE to solve the national immigration crisis we’ve been experiencing. This inability to share critical public safety information puts our community at risk.”

Mayor Mike Coffman of Aurora has questioned neighboring city Denver’s policies of welcoming migrants, and the impact it has had on neighboring communities including his. Coffman said one of the nonprofits contracted by Denver to resettle migrants worked with a landlord to place them in three apartment buildings in Aurora, where police say Venezuelan gang members terrorized residents. The incidents there drew the attention of President Trump, who has promised to carry out mass deportations, or what he dubbed “Operation Aurora” during his visit to the city last October.

Coffman said Johnston has refused to say how many migrants were placed in Aurora, so he filed an open records request to obtain the contract the city signed with the nonprofit. He said the contract included a clause allowing the agency to put migrants in other cities without notifying them.

Now as President Trump has said he is dissatisfied with the pace of deportations, his “Border Czar” Tom Homan told Fox News, “Sanctuary cities [are] a sanctuary for criminals, bottom line. So, we’re going to do everything we can to find them. Regardless of what it takes, we got a strong president in the White House; he’s giving us all the authority we need. We’re coming.”