Sanctuary Cities and Law Enforcement

Sanctuary cities have been controversial since their inception. But the debate over sanctuary cities has intensified in the last few years.

December 29, 2020

Article highlights

If you’ve kept up with the news throughout the election season, you probably heard debates over sanctuary cities. The term has become somewhat of a buzzword in the immigration debate.

Throughout his presidential campaign, President Trump called for an end to sanctuary cities, saying they protect immigrants who commit crimes.

Others have argued that cities and counties have a right to protect undocumented immigrants in their jurisdiction.

But what exactly is a sanctuary city, and how does it work?

Technically, there’s no official legal definition of what qualifies as a sanctuary city. The term usually refers to a city or county that protects undocumented immigrants by limiting cooperation with federal immigration authorities.

The methods of doing so vary. Some sanctuary cities restrict information sharing so as not to alert federal authorities to undocumented immigrants.

Some have laws that prohibit law enforcement officers from asking people about their immigration status.

Others use executive orders, agency policies, or non-binding resolutions to limit cooperation with federal immigration authorities.

And law enforcement personnel in some cities have unofficial practices that help protect immigrants from deportation.

The sanctuary city movement started in the 1980s as local law enforcement started pushing back against federal immigration law.

Now, the Center for Immigration Studies estimates that there are about 300 cities, counties, and states with policies that hinder federal immigration enforcement.

This includes many big cities such as New York, Boston, and New Orleans. It also includes states such as California, New Mexico, and Colorado.

How Do Sanctuary Cities Work?

Federal Immigrations and Customs Enforcement (ICE) is responsible for detaining and deporting undocumented immigrants.

However, local jails are usually run by county sheriff's offices. So ICE relies on local law enforcement to help find and detain undocumented immigrants.

For example, let's say a local police officer arrests someone for drunk driving. The officer fingerprints the suspect when booking them into the local jail.

The jail sends those fingerprint records to the FBI to check criminal history and arrest warrants. Then, the FBI will sometimes share the information with ICE to check immigration status.

If ICE finds that the suspect is undocumented, it may submit a detainer request to the local jail. Under the Department of Homeland Security’s Priority Enforcement Program, ICE can ask local law enforcement to detain the suspect for an extra 48 hours.

This gives ICE time to get a warrant, move to take custody of the immigrant, and start the deportation process.

However, it’s up to the local agency whether they listen to these requests. Federal courts have ruled that complying with these requests is voluntary since the 4th Amendment prohibits law enforcement agencies from holding someone in jail without a warrant.


Some law enforcement agencies work with ICE, openly sharing arrest information and holding suspects when requested. But in many “sanctuary cities,” law enforcement agencies ignore ICE detainment requests.

They choose to simply release the suspect once the charges are dropped, or bail paid. Some counties reject all ICE requests.

Others comply only in some cases—if the suspect has prior convictions or is on a terrorist watch list, for example.

Examples of Sanctuary Cities

Los Angeles was the first U.S. city to adopt sanctuary city practices. In 1979, the LA police department issued a mandate that barred officers from “initiating police action” in order to discover a person’s immigration status. It also stated that officers should not arrest people for illegal entry to the U.S.

The movement has grown since then. According to the Texas Tribune, local jails declined more than 18,600 ICE immigration detainer requests between January 2014 and September 2015. More than 11,000 of those were in California. Under California's TRUST Act, law enforcement officials can only comply with an ICE detainer request if the suspect has been convicted of a serious crime.

New York City has a law that forbids officers from detaining people for deportation unless ICE has a judge’s warrant. Another NYC law blocks ICE access to city jails and law enforcement facilities.

Other cities and counties block cooperation because of limited resources. For example, the Miami-Dade County Department of Corrections and Rehabilitation only honors detainer requests if the federal government agrees to reimburse the county for the costs.

The suspect in question also must have a forcible felony conviction. In the resolution that established these rules, a county attorney wrote that Miami-Dade County spent more than $1 million complying with ICE detainer requests in 2011.


Since the exact definition of a “sanctuary city” is often debated, it can be hard to find a list of sanctuary cities. But the Ohio Jobs & Justice PAC has noted hundreds of cities with policies that protect undocumented immigrants.

The Sanctuary City Debate

Sanctuary cities have been controversial since their inception. But the debate over sanctuary cities has intensified in the last few years.

In July 2015, San Francisco police released an undocumented immigrant despite a detainer request from the Department of Homeland Security. The man had several previous felony convictions and had been deported five times.


After his release, the man allegedly shot and killed a woman. The incident prompted renewed scrutiny of cities with sanctuary practices.

Arguments against sanctuary cities

After his election, Donald Trump promised to cut off federal funding to sanctuary cities and remove 2 million undocumented criminals from the U.S. He said sanctuary cities harbor dangerous criminals and result in “needless deaths.”

Some argue that sanctuary city practices make it more difficult for federal law enforcement agencies to combat gangs and terrorism.

"Sanctuary policies, official or de facto, result in safe havens (or safer havens) for illegal aliens involved in a variety of criminal enterprises,” the Ohio Jobs & Justice PAC says on its website. “Sanctuary policies inhibit the ability of law enforcement officers to accurately identify foreign nationals, which makes it more difficult to uncover their illegal activities.”

Also, the argument goes, when undocumented criminals don't get deported, police departments spend valuable time and resources re-arresting them.

Groups such as The Center for Immigration Studies say that sanctuary practices make immigration policy overly convoluted.

“That’s why immigration is a federal responsibility,” Jessica Vaughan, the Center’s director of policy, told The Washington Post. “You cannot have 3,000 different policies, it’s chaos.”

Arguments for sanctuary cities

Even with Trump’s threat of blocking funding, many of the cities and counties with sanctuary policies have said they will continue their practices.

Many argue that complying with ICE detainer requests could harm police-community trust. Community officials say strict immigration enforcement can make undocumented people afraid to report crimes.

Some worry that using local law enforcement agencies to enforce immigration policies could also result in discrimination. “We find this involvement of local jails really troubling," Lena Graber, an attorney for the Immigrant Legal Resource Center told The Washington Post.

"It really undermines the idea that the criminal legal system protects everyone when a police stop is a gateway to deportation.” 

Some law enforcement officials simply argue that complying with detainer requests drains valuable resources. Detaining undocumented suspects can cost local jails hundreds of thousands of dollars each year.

And, according to The New York Times, most of the immigrants deported under Obama’s presidency had committed minor crimes or had no criminal record.

Are Sanctuary Cities Constitutional?

In Printz v. United States, the Supreme Court ruled that the federal government cannot force state or local officials to enforce federal law.

Therefore, sanctuary cities are constitutional. The Constitution does not require local law enforcement agencies to help deport undocumented immigrants.

That’s the federal government’s job. However, some experts point out that the constitution may not protect cities and counties that refuse to share information with the federal government.

In Reno v. Condon, the Supreme Court ruled that the federal government could regulate states sharing people’s personal information.

In the decision, Chief Justice William H. Rehnquist wrote that the law in question did not violate the principles of federalism because it didn’t “require state officials to assist in the enforcement of federal statutes regulating private individuals.”


So the federal government can’t force local law enforcement agencies to detain undocumented immigrants. But it may be able to require them to share information about immigrants so federal officials can enforce immigration laws.

What it Means for Law Enforcement

Immigration policy and enforcement practices are complex and ever changing. And with Trump now in office, the debate over sanctuary cities isn’t going away anytime soon.

When creating policies for your law enforcement agency, you must take local laws and regulations into account. Immigration policies in your state, county, or city may facilitate cooperation with ICE or restrict cooperation.

You must comply with those laws. Be sure to collaborate with leaders in your city and county to make sure you are all on the same page.

Your agency doesn’t have to enforce federal immigration policy, but refusing to share information with the federal government could get you in trouble.

Restricting information could cause your agency to lose federal funding. So keep an eye on case law in this area.

As the debate over sanctuary cities continues, it’s increasingly important for your law enforcement agency to establish thorough policies.

Laws and standards change, so make sure your agency regularly updates policies and trains officers on correct practices.

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