Do Border Patrol agents have the same authority as Texas police, highway patrol?
Recent discussions about immigration enforcement have raised questions about what U.S. Customs and Border Patrol Agents can and can’t do compared to state or local police.
While their jobs may look similar from the outside — pulling over drivers, questioning people and checking IDs — their powers and limits under the law are different.
In Texas, that distinction matters because Border Patrol operates in what’s called a “100-mile border zone,” where agents have more authority than they would elsewhere in the country.
But even in that zone, their power isn’t unlimited. Here’s what to know.
Can Border Patrol legally stop drivers in Texas?
Yes, but it depends on where and why. Border Patrol agents can’t just pull someone over based on a feeling or appearance.
Their authority to stop vehicles on what’s called “reasonable suspicion” comes from a series of U.S. Supreme Court rulings interpreting the Fourth Amendment, which protects people from unlawful searches and seizures.
In a 1975 case called United States v. Brignoni-Ponce, the Court ruled that agents must have specific facts to believe someone might be in the country illegally before stopping a car.
In other words, it has to be more than a hunch.
Later cases, including United States v. Cortez (1981) and United States v. Arvizu (2002), said officers should look at the “whole picture,” meaning several small details together can amount to reasonable suspicion if they suggest illegal activity.
Federal law follows the same rule.
Under Title 8 of the U.S. Code, immigration officers can briefly question or detain someone only if they have reasonable suspicion, based on specific details, that the person has broken a law or is in the country unlawfully.
At permanent checkpoints near the border, agents can stop cars and ask about citizenship without needing an individual reason.
But if they’re patrolling on highways or other areas away from those checkpoints, they have to meet that higher legal standard before stopping anyone.
What is the 100-mile border zone?
This refers to an area up to 100 miles from any U.S. border, where Border Patrol has broader authority to operate.
In Texas, that includes parts of major cities like San Antonio, Houston, and El Paso.
Within this zone, agents can conduct vehicle stops and set up checkpoints, but their power is still limited to immigration-related issues.
Civil rights groups often warn that this wide enforcement zone blurs the line between border and interior policing.
What authority does Border Patrol have?
Border Patrol operates under federal law, not state law.
Their primary mission is to enforce immigration laws, prevent unlawful entry into the country and investigate smuggling or trafficking.
Agents can question people about their immigration status and search vehicles in certain situations, but their authority has limits.
For example, Border Patrol can detain someone on suspicion of violating immigration or federal laws, but they can’t arrest people for state-level crimes such as theft or assault.
If a case involves a state crime, agents must hand the person over to local or state police. Texas police and highway patrol officers have broader powers within the state.
What’s the difference between Border Patrol and Texas Highway Patrol?
Texas police and highway patrol officers can enforce all state laws, including traffic and criminal offenses, and can make arrests anywhere in Texas.
That includes stopping drivers for routine violations like speeding, running a red light or having a broken taillight.
Border Patrol agents, however, don’t have those same state-level powers. Their authority is tied to federal jurisdiction, which focuses on immigration and customs issues.
What are my rights if I’m stopped by Border Patrol?
You have the right to remain silent if questioned by Border Patrol agents.
You can tell an agent that you prefer to answer questions only in the presence of an attorney.
You don’t have to answer questions about your citizenship or immigration status, and your silence alone isn’t enough to justify arrest or detention.
However, if you’re a non-citizen in the country on a visa or other temporary status, you may be legally required to show immigration documents if asked.
Agents are also allowed to search your vehicle or belongings at official border crossings or checkpoints, even without probable cause, but more invasive searches require stronger justification.
This story was originally published December 11, 2025 at 9:00 AM.
