The Fourth Amendment: From General Warrants To Probable Cause

We trace the Fourth Amendment from colonial protests against general warrants to modern rules for warrants, cars, phones, and digital surveillance. We explain probable cause, reasonableness, and how courts adapt old principles to new technology without watering them down.

• roots in English common law and colonial resistance to general warrants
• James Otis’s protest and John Adams’s influence on state constitutions
• probable cause, sworn affidavits, and particularity in warrants
• the automobile exception and Carroll’s articulation requirement
• defining reasonableness versus arbitrary searches
• Kyllo and technology that reveals home details
• Katz’s reasonable expectation of privacy alongside trespass
• Jones and GPS tracking as both trespass and privacy intrusion
• metadata, mass surveillance, and the limits of older precedents
• why recent Fourth Amendment cases often show cross‑ideological agreement

Check Out the Civic Literacy Curriculum!

School of Civic and Economic Thought and Leadership

Center for American Civics

Transcript

Copy Transcript Copied

Setting The Stage: Fourth Amendment

SPEAKER_01 0:46

Welcome back to the Civics in a year podcast. Today we are talking to Dr. Beinberg about the Fourth Amendment. Dr. Beyenberg, what is the background of the Fourth Amendment?

SPEAKER_00 0:57

It's basically at its sort of earliest inspirations. It comes from English, the idea of English common law, protections about against warrants and arbitrary searches. But in the United States context, specifically, it's a reaction to a phenomenon that happened at the beginning of the sort of buildup to the American Revolution, which is an idea called general warrants. Effectively, that the British government would authorize law enforcement in the colonists to just have sort of a freestanding warrant. Whereas historically in England you needed a more kind of specific, a more specific articulation of what you're looking for. And this became particularly problematic in New England and particularly Boston. And so, for example, my memory is he was the attorney general. I'm

Colonial Roots And General Warrants

SPEAKER_00 1:43

trying to remember what the legal position was, but it was what it was titled, but functionally the attorney general of Massachusetts under the colonial government was a guy named James Otis, related to Merci Otis Warren and Warren. So Otis basically resigns in protest. He effectively says, like, I'm being asked to do things that are inconsistent with British traditions of civil liberties, that if we were in England, you wouldn't be able to just sort of take this waving warrant to go wherever you want to search whatever you wanted. And so he resigned in protest, even though he'd been one and gave up a very plum position. And a very young John Adams was very impressed by this. And this is part of why Otis became kind of a hero of his. Later on, Otis very quickly falls into poor health. So he sort of doesn't end up as one of the leaders of the revolution. But this causes a lot of the drafters of the various state constitutions to put in language that looks in most cases quite similar to the modern Fourth Amendment. Adams writes the Massachusetts Constitution, and his language is, I think, pretty close to the text of the current Fourth Amendment. But the Phil the Pennsylvania Constitution a few years earlier, which we've talked about and kind of knocked about, is one that the founders think is silly, but that's one that looks pretty similar to the modern Fourth Amendment. And so you can read through the text itself, but it basically tries to regularize the process of searches, right? Obviously, searches are legitimate, but they have to be, you know, they have to have probable cause. You have to have, if you're securing a warrant,

State Constitutions And Early Text

SPEAKER_00 3:27

basically somebody attesting to it. You don't necessarily need a warrant for every search. This is something that people mistake. There is a strong presumption of a warrant, but it says unreasonable searches, right? So for example, the courts have held that you don't necessarily need a warrant to search an automobile if you have probable cause, right? So if you see these people basically, if you see people hanging out at a drug deal and then driving away, you don't need

Probable Cause And The Warrant Process

SPEAKER_00 3:58

to go get you know go get a warrant because it's unreasonable. But you still need to be able to articulate. You know, I saw these people talking to somebody who's a known drug dealer, handing a packet, handing money, right? So you need to be able to sort of articulate why you want to search this thing. That was a case from Prohibition, actually, uh run running, whether you needed uh to do that. An opinion called Carroll versus United States States that I think is one of Taft's best cases. But they're very adamant that they have to have sort of the probable cause parts. Uh you can't just so again, unreasonability is basically the metric. And you might say that's arbitrary, but there's tons and tons and tons of case law to build it out. So the core of the Fourth Amendment really is sort of a combination of honoring, again, traditional British civil liberties and then being frustrated that those didn't seem to be extended in the colonial context. And so the various state constitutions had those had those in there to ensure that that civil liberty was protected.

SPEAKER_01 4:58

Can you, for our listeners, tell us what is a

The Automobile Exception And Carroll

SPEAKER_01 5:01

warrant?

SPEAKER_00 5:02

Sure. A great question. So a warrant is effectively a document authorizing the police or whatever the relevant law enforcement is. Generally, it's going to be your local or state police. Could be the FBI or something like that, if it's a you know a more distinct thing, but to search premises, particularly a house, an office, something along those lines, searching for evidence of criminal wrongdoing. And so you might so uh, for example, if a warrant is being issued against probable drug dealers, right, you're going to basically say, this is the facility that we want to search. Here's this address. We are looking for specific things. Again, you can't just say we'd like to kick the doors in and look for whatever we want in a phishing execution, right? You have to be able to articulate we're looking for evidence of drug paraphernalia, or we're looking for this, this, or that. And you have to basically have a police officer attesting to that and some level of, or again, a law enforcement officer attesting, offering like why it is that they think this and articulating the probable cause, right? We were told by confidential informant number five that, blah, blah, blah, blah, blah, or something along those lines. So a warrant is effectively a way to guarantee that basically, or not a guarantee overstates it, but a way to attempt to protect basically the authority of folks to maintain basically free liberty without a police state, but also still recognizing like we want law enforcement. And so a warrant is a way to basically regularize that process and the particular features of, like I said, you can look at the text of the Fourth Amendment, but it really is effectively, is this an arbitrary search? Or is there reason to believe that there's legitimate reason to do this? Again, it doesn't probable cause doesn't necessarily mean 100% certainty, but it means we're we're reasonably confident about it based on based on evidence. It's not it's not as high as the conviction standard, right? Beyond a reasonable doubt, but it's more than just like mere suspicion. Hey, here's the A piece of evidence about it, right? It's it's like are we pretty sure that this is the case?

SPEAKER_01 7:09

So now we kind of live in this world of technology that's moving very, very quickly. What does this look like in, you know, with advances of all of this technology?

SPEAKER_00 7:22

Right. So there's a couple of places. So the courts have wrestled with this uh in various ways. The the core thing that I think is important to say is the court does not take the idea to simply say, like a piece of technology that existed, that didn't exist then, therefore doesn't have Fourth Amendment implications. Right. You see similar logic, the way that they treat the Second Amendment, right? They don't just say that only applies to muskets. No, it applies to sort of weapons that are analogous. So similarly, you know, the courts have held in a few

What A Warrant Must Specify

SPEAKER_00 7:52

cases. I think probably the most explicit articulation of this is a case about whether you needed a warrant to use thermal scanners inside a house. It's a 2001 case that Scalia wrote. And effectively the question is, is this uh conceptually closer to a search of your house? And the majority of the Supreme Court said just because these thermal scanners didn't exist in the 1780s, you know, doesn't mean that we want to authorize this additional technology that functionally means now we're able to search your house. So in that case, and the court basically articulated and said, you know, the same principles, the same logic, the same ideas behind this apply, even if it's being used to technological developments. And so they use, again, the same kind of methodology they use on the Second Amendment or on the First Amendment, right? It's not like, ah, there wasn't an internet in 1780, so therefore there's no First Amendment. They said, no, like these principles still basically hold, the logic of them still holds. So again, there are a couple of places where this doctrine has gotten kind of a little complicated over the years. So one case is wiretapping in general. So in the 1920s, the Supreme Court basically said that wiretapping did not require, was not a search in the for this purpose, and so did not require a warrant. There were a couple of dissents in that case, including some that effectively said, like, no, sort of the original logic of this is this is intruding in your house, particularly if it's a if it's a call that's in your house. It might be a little more different if you're like in a pay phone or something, like a public pay phone. It gets a little more complicated in that case. The court overturned that about 40 years later in a case called Cats versus the United States. And they articulated so that there's almost two basic tests for the way that the court thinks about the Fourth Amendment. So one, something closer to the old standard. Is your property being trespassed on, right? Like, you know, you didn't authorize a police officer to walk into your house, right? You need a warrant for them to be able to basically trespass functionally onto your property. So that old test still stands. But they added to it a concurrence from uh Justice Harlan, which are created a sort of a test called a reasonable suspicion

Reasonableness And Probable Cause Standards

SPEAKER_00 10:06

of privacy, right? Basically, are you in a place where you have a reasonable suspicion of privacy? So in this case, you're on the telephone. You have a reason to like not assume that the whole world is listening into a conversation that like you and I might be having, even if I were in a payphone. I don't know for our younger listeners, a payphone, what's that, but my students laugh about that when we talk about this case. And uh so this creates sort of a parallel test. It doesn't replace the original test. And this came up again a few years later in an opinion called Jones versus United States, which is whether you needed a warrant to basically install a tracking device on a car. Obviously, if you're interfering with somebody's car, that would normally be kind of a trespass. And Justice Sodomayor, in what I think is probably her sort of strongest or best known opinion, or at least of her early years in the court, said, look, let's just make sure we have both of these tests. If it fails, either the trespass test or the reasonable expectation of privacy will invalidate the search. So the Fourth Amendment interpretation has been fairly robust, I would say, in terms of dealing with modern technology. There's one example that I would be negligent if I didn't talk about, which is sort of mass electronic surveillance. So not a telephone, but basically the internet. And this is where the original case from the 70s says effectively, do you have an expectation of privacy in who you talk to? Right. So to who in who you talk to. And originally, again, this is even before my time, you would get a record. I guess I saw a little bit of this early in my years, but you would get a record of who you called from the telephone company

Technology, Analogy, And Home Scans

SPEAKER_00 11:55

because you had to pay extra depending on if you were calling long distance. Right. And so and so the court said, no one really assumes this is private in a way that like a private conversation is. You know that the phone company has this, and this is not a sort of a secret. And so that created a a case that said effectively who you call is not necessarily a secret. And that has been used in some cases to defend some of the mass surveillance stuff. That was initially there's a the the lower courts and other people were sort of squabbling with this. A really terrific opinion by Judge Leon, so not a Supreme Court case, but a district court case, arguing, he said, effectively, like I don't think this case holds. The internet is so qualitatively different that we should treat this more like the regular wiretapping cases than the metadata who you're calling case. It ended up being sort of a moot discussion because Congress sort of stepped in and sort of tweaked the way that it was being dealt with. But that's the one case where I would say that the case law hasn't sort of stayed caught up in some ways. But otherwise, I always like reading these cases where the Supreme Court justices are saying, how do we best protect rights? Is it this test? Is it this test? You do see that on the Fourth Amendment in a way that you don't in a lot of other places where the there's more sort of ideological overstates it, but methodological division. The Fourth Amendment cases more recently tend to be unanimous or pretty close to it, or two different opinions basically saying, let's use this test or let's use this test, but we're both going to side with the same, usually the individual often. So the Fourth Amendment is one where they they have tried pretty hard to make sure that without changing the original meaning, without changing the original principles, but making sure that it applies, that it continues to be robustly applied.

SPEAKER_01 13:50

Dr. Weinberg,

Wiretaps, Katz, And Privacy Tests

SPEAKER_01 13:51

thank you so much. I mean, I feel like when you read the Fourth Amendment, and there's a lot in there, but you did a really good job at kind of distilling it down for our listeners. We appreciate it.