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

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Episode Transcript

SPEAKER_01 (00:00):
Welcome back to the Civics in a year podcast.
Today we are talking to Dr.
Beinberg about the FourthAmendment.
Dr.
Beyenberg, what is thebackground of the Fourth
Amendment?

SPEAKER_00 (00:10):
It's basically at its sort of earliest
inspirations.
It comes from English, the ideaof English common law,
protections about againstwarrants and arbitrary searches.
But in the United Statescontext, specifically, it's a
reaction to a phenomenon thathappened at the beginning of the
sort of buildup to the AmericanRevolution, which is an idea
called general warrants.

(00:31):
Effectively, that the Britishgovernment would authorize law
enforcement in the colonists tojust have sort of a freestanding
warrant.
Whereas historically in Englandyou needed a more kind of
specific, a more specificarticulation of what you're
looking for.
And this became particularlyproblematic in New England and
particularly Boston.

(00:52):
And so, for example, my memoryis he was the attorney general.
I'm trying to remember what thelegal position was, but it was
what it was titled, butfunctionally the attorney
general of Massachusetts underthe colonial government was a
guy named James Otis, related toMerci Otis Warren and Warren.

(01:17):
So Otis basically resigns inprotest.
He effectively says, like, I'mbeing asked to do things that
are inconsistent with Britishtraditions of civil liberties,
that if we were in England, youwouldn't be able to just sort of
take this waving warrant to gowherever you want to search
whatever you wanted.
And so he resigned in protest,even though he'd been one and

(01:38):
gave up a very plum position.
And a very young John Adams wasvery impressed by this.
And this is part of why Otisbecame kind of a hero of his.
Later on, Otis very quicklyfalls into poor health.
So he sort of doesn't end up asone of the leaders of the
revolution.
But this causes a lot of thedrafters of the various state
constitutions to put in languagethat looks in most cases quite

(02:02):
similar to the modern FourthAmendment.
Adams writes the MassachusettsConstitution, and his language
is, I think, pretty close to thetext of the current Fourth
Amendment.
But the Phil the PennsylvaniaConstitution a few years
earlier, which we've talkedabout and kind of knocked about,
is one that the founders thinkis silly, but that's one that
looks pretty similar to themodern Fourth Amendment.

(02:25):
And so you can read through thetext itself, but it basically
tries to regularize the processof searches, right?
Obviously, searches arelegitimate, but they have to be,
you know, they have to haveprobable cause.
You have to have, if you'resecuring a warrant, basically
somebody attesting to it.
You don't necessarily need awarrant for every search.

(02:48):
This is something that peoplemistake.
There is a strong presumption ofa warrant, but it says
unreasonable searches, right?
So for example, the courts haveheld that you don't necessarily
need a warrant to search anautomobile if you have probable
cause, right?
So if you see these peoplebasically, if you see people

(03:08):
hanging out at a drug deal andthen driving away, you don't
need to go get you know go get awarrant because it's
unreasonable.
But you still need to be able toarticulate.
You know, I saw these peopletalking to somebody who's a
known drug dealer, handing apacket, handing money, right?
So you need to be able to sortof articulate why you want to
search this thing.
That was a case fromProhibition, actually, uh run

(03:29):
running, whether you needed uhto do that.
An opinion called Carroll versusUnited States States that I
think is one of Taft's bestcases.
But they're very adamant thatthey 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'sarbitrary, but there's tons and
tons and tons of case law tobuild it out.

(03:51):
So the core of the FourthAmendment really is sort of a
combination of honoring, again,traditional British civil
liberties and then beingfrustrated that those didn't
seem to be extended in thecolonial context.
And so the various stateconstitutions had those had
those in there to ensure thatthat civil liberty was
protected.

SPEAKER_01 (04:12):
Can you, for our listeners, tell us what is a
warrant?

SPEAKER_00 (04:16):
Sure.
A great question.
So a warrant is effectively adocument authorizing the police
or whatever the relevant lawenforcement is.
Generally, it's going to be yourlocal or state police.
Could be the FBI or somethinglike that, if it's a you know a
more distinct thing, but tosearch premises, particularly a

(04:37):
house, an office, somethingalong those lines, searching for
evidence of criminal wrongdoing.
And so you might so uh, forexample, if a warrant is being
issued against probable drugdealers, right, you're going to
basically say, this is thefacility that we want to search.
Here's this address.
We are looking for specificthings.

(04:58):
Again, you can't just say we'dlike to kick the doors in and
look for whatever we want in aphishing execution, right?
You have to be able toarticulate we're looking for
evidence of drug paraphernalia,or we're looking for this, this,
or that.
And you have to basically have apolice officer attesting to that
and some level of, or again, alaw enforcement officer
attesting, offering like why itis that they think this and
articulating the probable cause,right?

(05:20):
We were told by confidentialinformant number five that,
blah, blah, blah, blah, blah, orsomething along those lines.
So a warrant is effectively away to guarantee that basically,
or not a guarantee overstatesit, but a way to attempt to
protect basically the authorityof folks to maintain basically
free liberty without a policestate, but also still

(05:42):
recognizing like we want lawenforcement.
And so a warrant is a way tobasically regularize that
process and the particularfeatures of, like I said, you
can look at the text of theFourth Amendment, but it really
is effectively, is this anarbitrary search?
Or is there reason to believethat there's legitimate reason
to do this?
Again, it doesn't probable causedoesn't necessarily mean 100%

(06:03):
certainty, but it means we'rewe're reasonably confident about
it based on based on evidence.
It's not it's not as high as theconviction standard, right?
Beyond a reasonable doubt, butit's more than just like mere
suspicion.
Hey, here's the A piece ofevidence about it, right?
It's it's like are we prettysure that this is the case?

SPEAKER_01 (06:22):
So now we kind of live in this world of technology
that's moving very, veryquickly.
What does this look like in, youknow, with advances of all of
this technology?

SPEAKER_00 (06:36):
Right.
So there's a couple of places.
So the courts have wrestled withthis uh in various ways.
The the core thing that I thinkis important to say is the court
does not take the idea to simplysay, like a piece of technology
that existed, that didn't existthen, therefore doesn't have
Fourth Amendment implications.
Right.
You see similar logic, the waythat they treat the Second

(06:56):
Amendment, right?
They don't just say that onlyapplies to muskets.
No, it applies to sort ofweapons that are analogous.
So similarly, you know, thecourts have held in a few cases.
I think probably the mostexplicit articulation of this is
a case about whether you neededa warrant to use thermal
scanners inside a house.

(07:16):
It's a 2001 case that Scaliawrote.
And effectively the question is,is this uh conceptually closer
to a search of your house?
And the majority of the SupremeCourt said just because these
thermal scanners didn't exist inthe 1780s, you know, doesn't
mean that we want to authorizethis additional technology that

(07:37):
functionally means now we'reable to search your house.
So in that case, and the courtbasically articulated and said,
you know, the same principles,the same logic, the same ideas
behind this apply, even if it'sbeing used to technological
developments.
And so they use, again, the samekind of methodology they use on
the Second Amendment or on theFirst Amendment, right?
It's not like, ah, there wasn'tan internet in 1780, so

(07:58):
therefore there's no FirstAmendment.
They said, no, like theseprinciples still basically hold,
the logic of them still holds.
So again, there are a couple ofplaces where this doctrine has
gotten kind of a littlecomplicated over the years.
So one case is wiretapping ingeneral.
So in the 1920s, the SupremeCourt basically said that

(08:19):
wiretapping did not require, wasnot a search in the for this
purpose, and so did not requirea warrant.
There were a couple of dissentsin that case, including some
that effectively said, like, no,sort of the original logic of
this is this is intruding inyour house, particularly if it's
a if it's a call that's in yourhouse.
It might be a little moredifferent if you're like in a

(08:39):
pay phone or something, like apublic pay phone.
It gets a little morecomplicated in that case.
The court overturned that about40 years later in a case called
Cats versus the United States.
And they articulated so thatthere's almost two basic tests
for the way that the courtthinks about the Fourth
Amendment.
So one, something closer to theold standard.
Is your property beingtrespassed on, right?

(09:00):
Like, you know, you didn'tauthorize a police officer to
walk into your house, right?
You need a warrant for them tobe able to basically trespass
functionally onto your property.
So that old test still stands.
But they added to it aconcurrence from uh Justice
Harlan, which are created a sortof a test called a reasonable
suspicion of privacy, right?

(09:21):
Basically, are you in a placewhere you have a reasonable
suspicion of privacy?
So in this case, you're on thetelephone.
You have a reason to like notassume that the whole world is
listening into a conversationthat like you and I might be
having, even if I were in apayphone.
I don't know for our youngerlisteners, a payphone, what's
that, but my students laughabout that when we talk about
this case.

(09:42):
And uh so this creates sort of aparallel test.
It doesn't replace the originaltest.
And this came up again a fewyears later in an opinion called
Jones versus United States,which is whether you needed a
warrant to basically install atracking device on a car.
Obviously, if you're interferingwith somebody's car, that would

(10:03):
normally be kind of a trespass.
And Justice Sodomayor, in what Ithink is probably her sort of
strongest or best known opinion,or at least of her early years
in the court, said, look, let'sjust make sure we have both of
these tests.
If it fails, either the trespasstest or the reasonable
expectation of privacy willinvalidate the search.

(10:24):
So the Fourth Amendmentinterpretation has been fairly
robust, I would say, in terms ofdealing with modern technology.
There's one example that I wouldbe negligent if I didn't talk
about, which is sort of masselectronic surveillance.
So not a telephone, butbasically the internet.
And this is where the originalcase from the 70s says

(10:48):
effectively, do you have anexpectation of privacy in who
you talk to?
Right.
So to who in who you talk to.
And originally, again, this iseven before my time, you would
get a record.
I guess I saw a little bit ofthis early in my years, but you
would get a record of who youcalled from the telephone

(11:08):
company because you had to payextra depending on if you were
calling long distance.
Right.
And so and so the court said, noone really assumes this is
private in a way that like aprivate conversation is.
You know that the phone companyhas this, and this is not a sort
of a secret.
And so that created a a casethat said effectively who you

(11:30):
call is not necessarily asecret.
And that has been used in somecases to defend some of the mass
surveillance stuff.
That was initially there's a thethe lower courts and other
people were sort of squabblingwith this.
A really terrific opinion byJudge Leon, so not a Supreme
Court case, but a district courtcase, arguing, he said,

(11:51):
effectively, like I don't thinkthis case holds.
The internet is so qualitativelydifferent that we should treat
this more like the regularwiretapping cases than the
metadata who you're callingcase.
It ended up being sort of a mootdiscussion because Congress sort
of stepped in and sort oftweaked the way that it was
being dealt with.

(12:12):
But that's the one case where Iwould say that the case law
hasn't sort of stayed caught upin some ways.
But otherwise, I always likereading these cases where the
Supreme Court justices aresaying, how do we best protect
rights?
Is it this test?
Is it this test?
You do see that on the FourthAmendment in a way that you
don't in a lot of other placeswhere the there's more sort of
ideological overstates it, butmethodological division.

(12:34):
The Fourth Amendment cases morerecently tend to be unanimous or
pretty close to it, or twodifferent opinions basically
saying, let's use this test orlet's use this test, but we're
both going to side with thesame, usually the individual
often.
So the Fourth Amendment is onewhere they they have tried
pretty hard to make sure thatwithout changing the original
meaning, without changing theoriginal principles, but making

(12:57):
sure that it applies, that itcontinues to be robustly
applied.

SPEAKER_01 (13:03):
Dr.
Weinberg, thank you so much.
I mean, I feel like when youread the Fourth Amendment, and
there's a lot in there, but youdid a really good job at kind of
distilling it down for ourlisteners.
We appreciate it.