- [Kim] Hey this is Kim from Khan Academy,
and today I'm talking with some experts
about the Fourth Amendment.
This is the Fourth Amendment of the Bill of Rights,
and the Fourth Amendment deals with
unreasonable search and seizure.
So here's the official text of the amendment.
It says, "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 probably cause, supported by Oath or affirmation,
and particularly describing the place to be searched,
and the persons or things to be seized."
To learn more about the Fourth Amendment,
I talked to two law professors
who specialize in criminal law,
Professor Tracey Meares of Yale University
and Professor Orin Kerr of George Washington University,
and he's a particular expert
in criminal procedure and computer crime.
Professor Kerr, can you tell us a little bit about
what the Fourth Amendment is and why the Framers
were interested in protecting these rights in particular?
- [Orin] The Fourth Amendment is a ban
on unreasonable searches and seizures by the government.
It's something the Framers were interested in because
they wanted to limit the government's power.
At the time of the framing,
the English king had engaged in some pretty bad things
that the Framers wanted to stop,
and one of those was raiding people's homes
with what was called a general warrant.
A general warrant was basically a warrant
that said the police could go anywhere
and look for anything without any limit.
- [Kim] I asked Professor Meares to explain
a little bit more about general warrants.
She's a professor at Yale Law School
who specializes in criminal procedure
and criminal law policy.
- [Tracey] They were a general warrant allowing
these officials to search people's homes, places, papers,
the kinds of things that the Fourth Amendment lists
in ways that people thought was not okay.
The Fourth Amendment was primarily concerned
with a couple of things.
One, a case involving seditious libel investigation,
it's a case called Entick,
and a warrant was issued authorizing Entick,
that's the subject of the warrant,
his arrest and the seizure of all of his books and papers
so that he could be prosecuted for seditious libel.
That case isn't as well known as the second case,
which is called the Writs of Assistance case,
and basically the Writs of Assistance involved
customs inspectors who were trying to crack down
on smuggling that was affecting Boston's economy.
So to aid in that task, inspectors used writs of assistance
that were issued by the king
and authorized the inspectors both to draft assistance,
hence the name, writs of assistance,
and to search any place where
smuggled goods might be concealed.
- [Orin] The Framers wanted to put an end to that,
and so they said no general warrants are allowed
and searches and seizures have to be reasonable.
That really means is the government can't just stop anyone,
arrest anyone, break into someone's house.
There are limits as to what the government can do.
- [Kim] But what are those limits?
What determines probable cause for a search,
and what renders a search and seizure unreasonable?
- [Orin] Yeah, what counts as unreasonable
is a really big question.
There are different answers different courts have suggested,
but the basic idea is that first,
if the government has a valid warrant,
a search or seizure is reasonable,
if the warrant, if a judge has signed off and said,
"Yeah the government has probable cause
to search this place for particular evidence."
Then the government can do that.
And then the Supreme Court has laid out a bunch
of what they call exceptions to the warrant requirement,
which are also reasonable searches.
So for example, if a person consents to a search,
that's reasonable.
Or in the case of a car, a car can be searched
without a warrant based on probable cause.
That's called the automobile exception.
There are rules that govern when the police
can stop somebody temporarily.
When the government needs an arrest,
they need probable cause.
There are basically all sorts of rules that
the Supreme Court has laid out on a bunch of different cases
that say what counts as an unreasonable search or seizure.
The Supreme Court has said that probable cause
means a fair probability that evidence will be found
in a particular place or
that a particular person committed a crime.
So fair probability is the language.
Now that's not something the Supreme Court has said,
that's not 50%, that doesn't mean
it's more probable than not.
It just means there's pretty good reason to think
that there's evidence in a particular place
or a particular person committed a crime.
So it doesn't mean a hunch.
It doesn't mean the officer just
had the idea pop into his head.
But it also doesn't mean that the officer is certain.
There's just gotta be a pretty good reason,
but not certainty to think that
that person committed the crime but there's evidence there.
- [Kim] But when I asked Professor Meares the same question,
she wasn't convinced it was so easy to tell
what counts as probable cause.
So what counts as a true probable cause
to issue a warrant upon?
- [Tracey] (sighs)
- [Kim] Sorry, we could just skip this instead.
- [Tracey] Let's take a second.
I taught this today.
These aren't questions that you can just simply answer.
No one can, actually.
There is, literally I taught today
the fact that there is no real law
on what probable cause is.
It's inherently a factual determination.
- [Kim] So how does this work in practice?
I asked Professor Kerr if it's the case that
a police officer has to convince a judge
that there's probable cause to issue a warrant.
- [Orin] Yeah, so it can come up in two ways.
In some cases, the Supreme Court says
that the police have to go to a judge first
and get a warrant and then they have to convince the judge
that what they're about to do is based on probable cause.
In another case, it's come up when the government
has searched first or arrested first,
and then they come back with the evidence
or come back with the person who was arrested
and then there's a hearing as to whether
there was probable cause
for the arrest that already occurred.
So either way, the standards are the same.
It's that fair probability idea.
Ultimately, up to a judge
whether the police were right or wrong
in doing what they did.
- [Kim] Interesting, so there is a little bit of
prior legwork involved in some cases.
What happens in cases when it might be really important
to get evidence, say if there's a bomb threat?
- [Orin] So there are some rules
that allow searches or seizures without a warrant,
under what they call exigent circumstances.
That basically means there was an emergency.
So the government had to act without a search warrant.
And so, if there's a ticking time bomb
that they think is gonna go off in a package
and they've got good reason to think there is
this ticking time bomb in the package,
they don't have to say, hey we're gonna go find a judge
because by the time they do that,
the bomb might have gone off.
They can search that package
under this exigent circumstances idea.
So that's an exception to the rules,
although beyond that, there's no difference between
a serious case and a less serious case
under the Fourth Amendment.
They're kind of all serious cases.
So the courts have to follow and the police have to follow
the same rules in less serious and more serious cases.
- [Kim] Professor Meares gave me an example
of what seemed like a less serious case,
but it's still a really interesting example
of what counts as an unreasonable search and seizure.
- [Tracey] I'll give you one more case
that I'm sure the high school students would love
and my students love it.
It's a case where a person was sitting in a noodle shop
in front of a window, eating a big bowl of noodles,
clear soup with noodles,
and a police officer walks by the person eating the noodles
and notices something floating in the bowl of noodles.
So he enters into the store
where the person is eating the noodles.
And the person has left temporarily the bowl of noodles
to get a napkin or go to the bathroom or something.
And then the police officer approaches the bowl,
picks up the person's spoon,
and stirs the noodles to see if he can find anything,
and some baggies of crack float to the top.
Did the person have a reasonable expectation of privacy
in their food?
- [Kim] In their soup?
- [Tracey] In their soup.
- [Kim] How did they rule?
- [Tracey] They ruled that the stirring was a search.
So if it is a search, i.e., that you have a subject of
interest in privacy in your soup
that society is prepared to recognize as reasonable,
then the police officer would have to get a warrant
before stirring the soup.
- [Kim] This raises the question,
where do I have Fourth Amendment rights?
Are some locations protected and not others?
- [Orin] The building block of the Fourth Amendment
is really that you have Fourth Amendment rights
in your home, in your pockets, in your packages,
but you don't have Fourth Amendment rights outside.
You don't have Fourth Amendment rights in what
you're doing outside or if the police want to walk
on what they call open fields, at public streets,
you don't have Fourth Amendment rights in that.
So thinking about how the Fourth Amendment applies
just in the physical world,
if the police want to break into your home,
they need a search warrant.
If the police want to watch you walk down the street,
they don't need anything.
It's not a search or a seizure,
so they can do anything they want, just watching you.
If they want to arrest you,
they need probable cause to believe you committed a crime.
So those are really the building blocks
of the Fourth Amendment that going back
to 18th century technology.
And then the question becomes, alright,
well how do you update that to a modern world?
- [Tracey] It's also the case that the Fourth Amendment
applies to seizures,
what police have to show before they arrest a person
or temporarily stop them
or briefly pat their body on the outside,
their body for weapons.
All of those questions are Fourth Amendment questions
as are questions involving how much force
police actually use to effect the arrest.
Once we've decided that an arrest is legitimate.
So we haven't talked about any of those questions,
but the Fourth Amendment governs
all of that and remember the Fourth Amendment governs
all of those topics in a context in which
the Framers' motivations for enacting the Fourth Amendment
have absolutely nothing to do
with most of those things I just mentioned.
- [Kim] But the Fourth Amendment also has implications
that go beyond warrants and seizures.
Professor Meares thinks that one of the biggest
Fourth Amendment issues today is discretion.
- [Teresa] Many people have thought
much more about how the Fourth Amendment protects privacy
than how the Fourth Amendment addresses discretion.
- [Kim] And by discretion in this case,
you mean what they get to decide to do on their own, right?
- [Tracey] Exactly so.
And one way to see the difference between those two things
is to think about a medal detector in an airport.
So long as everyone is required to go through
the metal protector, there is no law enforcement
discretion involved.
- [Kim] So this is kind of where the public safety
aspect comes in, that if we're all subject to
non-invasive procedures at the whim of police.
It's a little different than if individuals
are kind of plucked for that reason.
- Right, it's just pointing out that targeting,
the targeting of people or invasions
is a different problem than the invasion problem itself.
And so, if all we ever do is think about
privacy invasion without thinking about
the discretion problem,
then we're missing something important.
- [Kim] For Professor Kerr, however,
the most important issue at stake today
regarding the Fourth Amendment
is how it will apply to electronic media.
- [Orin] Well, the big question I think is
how the Fourth Amendment is going to apply
to searches and seizures of computers, of emails,
the Internet,
new technologies that we all use every day,
we wake up in the morning and hope on line or go on Twitter
or whatever you use online.
Lots and lots of communication online all around the world
and how does the Fourth Amendment apply to that
is something that the courts are beginning to answer
but they've only started to answer.
Some really, really hard questions of kind of translating
that physical world concept of the Fourth Amendment
to the world of computers that we live today.
So as we've learned, the Fourth Amendment ensures
that government authorities can't raid homes,
pockets or papers without a warrant issued by a judge,
and then only if there's a probable cause
to believe there is reason for a search.
What's tricky is deciding what counts as probable cause
and whether it's discriminatory to select
some people to search but not others.
And how do we translate the Fourth Amendment
to a world where our papers are all digital.
Should the police be permitted to search our cellphones,
our browsing histories, our private social media profiles?
You can learn more about the Fourth Amendment
by checking out the National Constitution Center's
interactive constitution
and Khan Academy's resources on US government and politics.