What “Sanctuary City” Really Means in Massachusetts: Understanding Lunn v. Commonwealth

The term “sanctuary city” is often misunderstood—and sometimes intentionally misrepresented. For immigrants and their families, the confusion can create unnecessary fear. For local governments and police departments, it can raise questions about what the law actually requires.

In Massachusetts, one of the most important legal decisions shaping so-called “sanctuary” policies is Lunn v. Commonwealth (2017). Understanding this case helps clarify what local authorities can—and cannot—do when it comes to federal immigration enforcement.

What Was Lunn v. Commonwealth About?

In Lunn v. Commonwealth, the Massachusetts Supreme Judicial Court addressed a critical question:

Can Massachusetts law enforcement hold someone in custody solely based on an ICE detainer?

The court’s answer was clear: No.

An ICE detainer is a request from federal immigration authorities asking local law enforcement to hold someone for up to 48 hours beyond their release date so ICE can take custody. The court ruled that, under Massachusetts law, there is no legal authority for state or local police to honor these detainer requests unless they are accompanied by a judicial warrant.

In other words, without a judge-issued warrant, holding someone for ICE would be an unlawful arrest under state law.

What This Means for “Sanctuary City” Policies

After Lunn, many Massachusetts cities and towns reviewed or reaffirmed policies limiting cooperation with federal immigration enforcement. These policies are often labeled “sanctuary” policies, but legally speaking, they are about complying with state law and constitutional protections.

Importantly:

• Local police are not allowed to detain someone solely for immigration purposes without a warrant

• Massachusetts communities do not have a legal obligation to enforce federal civil immigration law

• Immigration enforcement remains the responsibility of federal authorities, not local police

This does not mean that cities are “hiding” people from ICE or ignoring public safety. It means local governments are respecting legal boundaries and protecting residents’ civil rights.

What Lunn Does—and Does Not—Protect

It’s important to be honest and clear about the scope of the decision.

What Lunn does:

• Protects individuals from being unlawfully detained by local police

• Affirms that immigration detainers are requests, not orders

• Reinforces constitutional safeguards against unlawful arrest

What Lunn does not do:

• It does not prevent ICE from enforcing immigration law

• It does not grant immigration status or immunity from deportation

• It does not apply outside of Massachusetts state and local custody decisions

ICE can still arrest individuals directly, but it must do so using its own legal authority.

Why This Matters for Immigrant Communities

When local police are used as immigration enforcement tools, immigrant communities often become afraid to:

• Report crimes

• Seek help as victims or witnesses

• Access emergency services

By limiting local involvement in immigration enforcement, policies grounded in Lunn help ensure that public safety works for everyone, regardless of immigration status.

Courts have long recognized that trust between communities and law enforcement makes cities safer—not less safe.

Know Your Rights

If you or a loved one are interacting with law enforcement in Massachusetts:

• You generally cannot be held past your release time without a judicial warrant

• You have the right to remain silent and to speak with an attorney

• Immigration status alone is not a crime

Because immigration law is complex and constantly changing, getting reliable legal advice is critical.

We’re Here to Help

At an immigrant-friendly law firm, our goal is not only to represent our clients, but to educate and empower them. Understanding decisions like Lunn v. Commonwealth can help immigrants and their families make informed choices and protect their rights.

If you have questions about immigration enforcement, detention, or your legal options, we encourage you to speak with an experienced immigration attorney who understands both federal law and Massachusetts-specific protections.