The Border Search Exception to the Fourth Amendment
Issues pertaining to the U.S.-Mexico border have increasingly pervaded the American public consciousness, particularly in this century. From the establishment of the Department of Homeland Security (DHS) in 2002, the U.S. Customs and Border Protection (CBP) in 2003, and the Immigration and Customs Enforcement (ICE) in 2003, to recent political promises of a physical wall and deportations of undocumented people, America’s laws, policies, and political rhetoric have turned their attention to immigration, and more particularly, unlawful immigration at the U.S.-Mexico border. While much attention has been focused on emotionally charged issues, such as the separation of families, the influx of illicit drugs, and crime—and deservedly so—another issue, with possibly monumental implications, has largely escaped popular discourse: the conflict between individuals’ constitutional rights and the government’s interests to preserve public safety.
The Fourth Amendment to the United States Constitution provides,
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
However, as is the case with many other constitutionally conferred rights, our nation’s courts have articulated certain limitations to individuals’ Fourth Amendment rights to not be subjected to unreasonable search and seizures. Of particular scrutiny in this article is the border search exception to the Fourth Amendment.
While issues surrounding the U.S.-Mexico border have recently intensified, border-related constitutional tensions have long been relevant in American history. In one of the earliest articulations of the limited scope of Fourth Amendment applicability, the Supreme Court in Carroll v. United States, 267 U.S. 132 (1925) acknowledged the distinctive nature of a national border, and thus, how searches and seizures within a border context are unlike searches and seizures in other non-border scenarios.
Carroll involved two men who were indicted and convicted for transporting liquor in their automobile, which was a violation of the National Prohibition Act at the time. The men challenged their conviction because they contended it was based on evidence acquired by a search and seizure of their vehicle in violation of their Fourth Amendment rights. However, Chief Justice William Howard Taft, writing the majority opinion, resoundingly rejected this argument. First, Chief Justice Taft examined the legislative history of the National Prohibition Act, in which Congress rejected efforts to prohibit all searches on property or premises absent a search warrant because such a blanket ban would render a law enforcement officer useless.
Particularly of note was the recognition that, on a practical level, requiring a warrant to search an automobile would be an impossible task because the automobile would be “beyond the reach of the officer” before any warrant could be secured. Thus, the Court began to craft its scope of what constitutes an unreasonable search and seizure under a Fourth Amendment analysis through a practical lens.
Chief Justice Taft continued his analysis of what constitutes a “reasonable” search and seizure through an originalist framework, noting that the Fourth Amendment must be “construed in the light of what was deemed [unreasonable] when it was adopted.” Importantly, the Congress which proposed the Fourth Amendment recognized that searches conducted at a border were “reasonable,” evidenced by its enactment of a customs statute that granted customs authorities the power to enter and search vessels they suspected to contain concealed merchandise subject to duties.
Chief Justice Taft also recognized what would be a fundamental feature of the Supreme Court’s Fourth Amendment analyses, asserting that such analyses must “conserve public interests as well as the interests and rights of individual citizens”—in other words, a balancing test. Aligning with Congress’ recognition of a delineation of searches and seizures conducted in different settings through its legislative language, the Court here held that Fourth Amendment protections must be construed with consideration of the practicability of securing a warrant in a given setting and provided a carve-out for international boundaries.
[Travelers] may be so stopped in crossing an international boundary because of national self protection reasonably requiring one entering the country to identify himself as entitled to come in, and his belongings as effects which may be lawfully brought in.
The Supreme Court continued to refine its carve-out in cases like Carroll, with perhaps its strongest language coming in United States v. Ramsey, 431 U.S. 606 (1977). Ramsey involved two men who were convicted of possession of narcotics based on evidence obtained via a customs officer’s warrantless search on their international mail. Justice Rehnquist, writing the majority opinion of the Court, asserted an unequivocal stance on the constitutionality of border searches.
Border searches, then, from before the adoption of the Fourth Amendment, have been considered to be "reasonable" by the single fact that the person or item in question had entered into our country from outside. There has never been any additional requirement that the reasonableness of a border search depended on the existence of probable cause. This longstanding recognition that searches at our borders without probable cause and without a warrant are nonetheless "reasonable" has a history as old as the Fourth Amendment itself.
In justifying this assertion—that a border search is “reasonable” based on the fact that it is conducted at the border—Justice Rehnquist cited Almeida-Sanchez v. United States, 413 U.S. 266 (1973), in which the Supreme Court held that the federal government has the power to exclude aliens from the country, and that this power can be “effectuated by routine inspections and searches of individuals or conveyances seeking to cross [America’s] borders.”
However, Justice Rehnquist seemed to have completely ignored the remainder of the Almeida-Sanchez opinion. Almeida-Sanchez involved a Mexican citizen who was convicted on drug charges based on evidence acquired via a warrantless search conducted by the United States Border Patrol on his automobile twenty-five miles north of the border. Importantly, at this point, federal statutory law provided that warrantless searches of automobiles may only be conducted within a “reasonable distance from any external boundary of the United States,” and under the Department of Homeland Security’s regulations, a “reasonable distance” was defined as “within 100 air miles from any external boundary of the United States.” Had the Court adopted what would be Justice Rehquist’s expansive reading of its past articulations on the border search exception, it likely would have affirmed the Ninth Circuit’s decision to affirm the drug conviction. Yet, despite the search taking place within the federally defined “reasonable distance,” the Almeida-Sanchez Court rejected the idea that Justice Rehnquist posited.
It is not enough to argue, as does the Government, that the problem of deterring unlawful entry by aliens across long expanses of national boundaries is a serious one. The needs of law enforcement stand in constant tension with the Constitution's protections of the individual against certain exercises of official power. It is precisely the predictability of these pressures that counsels a resolute loyalty to constitutional safeguards.
Unfortunately, in the wake of the Ramsey precedent, courts have continued to uphold the constitutionality of warrantless border searches. For example, in United States v. Vergara, 884 F.3d 1309 (2018), a recent case before the Eleventh Circuit Court, the Court emphasized that “border searches never require a warrant or probable cause.” Here, a man who traveled from Mexico to Florida had his cell phones forensically examined without a warrant, which led to the collection of incriminating evidence against him. The Court, however, affirmed his conviction and sentence, depending heavily on the Ramsey decision that border searches are not subject to the Fourth Amendment’s probable cause and warrant requirements.
This article does not dispute that the federal government has genuine security interests within border contexts—they certainly do. However, the reality is that federal agents are frequently interrogating and searching American citizens, disrupting people’s livelihoods, and operating with intimidation and impunity. Many of these interactions are well-documented. With continuous technological improvements, it is critical to note that individuals’ privacy interests are not the same as they were during the time of the Ramsey or Carroll decisions. Courts must reevaluate the border search exception with consideration to evolving practical realities and heed Justice Robert Jackson’s remarks in his Brinegar dissent:
[Fourth Amendment rights] are not mere second-class rights but belong in the catalog of indispensable freedoms. Among deprivations of rights, none is so effective in cowing a population, crushing the spirit of the individual and putting terror in every heart. Uncontrolled search and seizure is one of the first and most effective weapons in the arsenal of every arbitrary government. [1]
338 U.S. 160, 180 (1949), Jackson dissenting.
[1] Fittingly, the Almeida-Sanchez Court quoted Justice Jackson’s resounding advocacy for the protection of Fourth Amendment rights, another indication of how Justice Rehnquist fundamentally misread the Court’s majority opinion.
Kevin Kim (‘24) is a senior at Brown University, concentrating in International and Public Affairs with a certificate in Engaged Scholarship. He is a staff writer for the Brown Undergraduate Law Review and can be contacted at kevin_s_kim@brown.edu.
Maia Eng (‘26) is a sophomore at Brown University concentrating in International and Public Affairs. She is an editor for the Brown Undergraduate Law Review and can be contacted at maia_lourdes_eng@brown.edu.