General Discussion

https://www.aclu.org/know-your-rights/border-zone

Are immigration officials allowed to stop people in places wholly inside the U.S.?
U.S. Customs and Border Protection, the federal agency tasked with patrolling the U.S. border and areas that function like a border, claims a territorial reach much larger than you might imagine. A federal law says that, without a warrant, CBP can board vehicles and vessels and search for people without immigration documentation “within a reasonable distance from any external boundary of the United States.” These “external boundaries” include international land borders but also the entire U.S. coastline.

Are there limitations to immigration officials’ power?
The Fourth Amendment to the U.S. Constitution protects against arbitrary searches and seizures of people and their property, even in this expanded border area. Furthermore, as a general matter, these agents’ jurisdiction extends only to immigration violations and federal crimes. And, depending on where you are in this area and how long an agent detains you, agents must have varying levels of suspicion to hold you.

We will examine specific scenarios where one might encounter CBP in more depth, but here are your key rights. These apply to every situation, outside of customs and ports of entry.

You have the right to remain silent or tell the agent that you’ll only answer questions in the presence of an attorney, no matter your citizenship or immigration status. You do not have to answer questions about your immigration status. You may simply say that you do not wish to answer those questions. If you choose to remain silent, the agent will likely ask you questions for longer, but your silence alone is not enough to support probable cause or reasonable suspicion to arrest, detain, or search you or your belongings.
A limited exception does exist: for people who do have permission to be in the U.S. for a specific reason and for, usually, a limited amount of time (a “nonimmigrant” on a visa, for example), the law does require you to provide information about your immigration status if asked. While you can still choose to remain silent or decline a request to produce your documents, people in this category should be aware that they could face arrest consequences. If you want to know whether you fall into this category, you should consult an attorney.

Generally, an immigration officer cannot detain you without “reasonable suspicion.” Reasonable suspicion is less robust than probable cause, but it is certainly not just a hunch or gut feeling. An agent must have specific facts about you that make it reasonable to believe you are committing or committed, a violation of immigration law or federal law.
If an agent detains you, you can ask for their basis for reasonable suspicion, and they should tell you.
An immigration officer also cannot search you or your belongings without either “probable cause” or your consent. If an agent asks you if they can search your belongings, you have the right to say no.
An immigration officer cannot arrest you without “probable cause.”
That means the agent must have facts about you that make it probable that you are committing, or committed, a violation of immigration law or federal law.
Your silence alone meets neither of these standards. Nor does your race or ethnicity alone suffice for either probable cause or reasonable suspicion.

Other important factors to keep in mind:

If an agent asks you for documents, what you need to provide differs depending on your immigration status. U.S. citizens do not have to carry proof of citizenship on their person if they are in the United States. If you have valid immigration documents and are over the age of 18, the law does require you to carry those documents on you. If you are asked by an immigration agent to produce them, it is advisable to show the documents to the agent or you risk being arrested. If you are an immigrant without documents, you can decline the officer’s request. An agent may likely ask you more questions if you decline a request. No matter what category you fall into, never provide false documents to immigration officials.

People who have entered the U.S. without inspection by an immigration official may be subject to expedited removal from the U.S. Expedited removal is a summary deportation that bypasses an immigration judge. The federal government says that it will only attempt to apply expedited removal to individuals who have entered the United States without inspection in the last 14 days, have been encountered by an immigration officer within 100 miles of the border, and meet certain other criteria. If you are told that you are subject to expedited removal but do not fall within that category, you should let the agents know. Also, if you fear persecution if returned to your country of origin, you should immediately inform the agents of your fear.