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During a routine traffic stop, a drug-detection dog alerted police to marijuana in Roy Caballes' car trunk. An Illinois court convicted Caballes of cannabis trafficking. Caballes appealed and argued the search violated his Fourth Amendment right to be free from unreasonable searches and seizures. The state appellate court affirmed the conviction. The Illinois Supreme Court reversed and ruled police performed the canine sniff without specific and articulable facts to support its use, "unjustifiably enlarging the scope of a routine traffic stop into a drug investigation."
Does the Fourth Amendment's search and seizure clause require a reasonable articulable suspicion to conduct a canine sniff during a routine traffic stop?
Justice John Paul Stevens delivered the Court's 7-2 opinion that Caballes' Fourth Amendment rights were not violated. The Constitution did not require police to have reasonable suspicion to use a drug-detection dog on a car during a legal traffic stop. No legitimate privacy was at risk, the Court argued, because the dog only alerted to an illegal drug.
Argument of Lisa Madigan
Justice Stevens: We will now hear argument in Illinois against Caballes.
General Madigan.
Ms Madigan: Thank you, Justice Stevens, and may it please the Court:
This Court has made clear on several occasions, including 21 years ago in Place and 4 years ago in Edmond, that a sniff by a drug-detection dog is not a Fourth Amendment search, and if something is neither a search nor a seizure, then it requires no Fourth Amendment justification.
Justice Souter: Well, we've held that it's certainly not a... a full-blown search.
It's not a search in the classic sense, but a Terry stop isn't an arrest in... in the classic sense either.
We... we have said that that is a kind of seizure.
Why do... I think your... your argument assumes that this for... for purposes of search analogies that something is either a... a full-dress search or it's not a search at all.
Why isn't there a... a possibility of... of a kind of middle ground searches just as there is on seizures?
Ms Madigan: Well, this Court made clear in Arizona v. Hicks that it did not want to go down the road of creating something known as a quasi-search so that courts and police officers would be in the position of trying to determine whether or not something was a search or not.
Justice Souter: Oh, I... I can... I can just imagine the problems, but I mean, what... I think what's... what the... what's bothering me about the case is that if we persist in... in saying that... that it's... that it's an either and or question with no question with no possible gradation, then I assume nothing prevents the police from taking the dogs through every municipal garage in the United States and I suppose there's nothing that prevents the police from taking the dogs up to any homeowner's door, ringing the bell, and seeing if the dog gets a sniff of something when the door is opened.
We're... we're opening rather a... a large vista for... for dog intrusions, and... and that's what's... that's what's bothering me.
Why... why should we... why should we open that vista if there is a possibility of a... of a middle ground that would prevent it?
Ms Madigan: Well, I would start with the reality that dog sniffs by their very nature, as this Court recognized in both Place and Edmond, are very unique both in terms of the manner in which the sniff is conducted, as well as the content of... of the information that the sniff reveals, so that a dog sniff is only going to be able to reveal the presence or absence of contraband.
And this Court has recognized that individuals have no privacy interest in the possession of contraband.
Justice Ginsburg: Does that imply that your answer is yes to the question?
If we say, as you urge, a dog sniff is not a search, then the police are free to parade up and down every street in the country with dogs sniffing car trunks.
Ms Madigan: Yes.
Because a sniff is not a search, a police officer would be able to take a narcotics-detection dog down the street with him or her.
I can tell you that because of the limited resources... and this is a point brought up in the Illinois Association of Chiefs of Police amicus brief... that that is not likely to occur.
In addition, I can also tell you that in the State of Illinois, the Illinois State police do not train their dogs nor do they use their dogs on people.
They only use them on objects.
But yes, in answer to both of your questions, because a dog sniff does not constitute a search, dogs could be used to walk down streets.
They could, hypothetically, be used in parking lots, and at times they are used in parking lots.
Justice Scalia: But they are used.
I mean, we don't have to make it up.
From cases we've had here, we know that they're used in places like bus depots to... to sniff luggage that... that passengers have carried through on... on buses.
Ms Madigan: Yes, they are.
Justice Scalia: And the republic seems to have survived.
Ms Madigan: I agree.
Justice Ginsburg: One could characterize those episodes under the, quote, special needs doctrine.
I mean, we are exposed to searches at airports that we would not put up with walking up and down an ordinary street.
So the dogs at the terminals one expects nowadays.
Justice Scalia: No.
These aren't sniffs for... for explosives.
These are sniffs for drugs and... and these... these are not buses that are coming in from France.
They're coming in from one American city to another.
And... and there's no more need in... in that case than there was in this case.
It was just a good... a good place to find criminals who were carrying unlawful drugs.
Ms Madigan: In the present case, Mr. Caballes was traveling from Las Vegas, Nevada apparently on his way to Chicago, Illinois.
He was pulled over for speeding.
Another officer overheard when Master Sergeant Gillette called in to dispatch that he effected--
Justice Stevens: May I interrupt, General Madigan?
Ms Madigan: --You may.
Justice Stevens: He was pulled over for speeding at 71 miles an hour in a 65 mile an hour zone on I-80.
Right?
Ms Madigan: Yes, that is correct, Justice Stevens.
Justice Stevens: Did they know in advance that he was someone to look for?
Because I don't imagine you arrest everybody on I-80 that goes 70 miles an hour.
I've done it many times myself.
[Laughter]
Justice Scalia: Inadvertently.
[Laughter]
Ms Madigan: We always like to have you in Illinois.
Obviously, the Illinois State Police have the ability to pull somebody over whether they're going 1 mile over the speed limit or 26 miles over the speed limit, but there is nothing in the record to indicate that they were looking for Mr. Caballes as he was traveling eastbound on I-80 towards Chicago.
Justice Stevens: Does the record tell us what time of day it was?
Ms Madigan: Yes.
It was approximately 5:10 p.m.--
Justice Stevens: Thank you.
Justice Kennedy: You... you answered one of the earlier questions about the possible intrusiveness of dogs everywhere by saying, well, you don't have a privacy interest in contraband, but that's never true.
You don't have a privacy interest in the murder victim's body, but you still have to have a warrant to go in and get it.
So that... that just doesn't work unless I missed something.
Ms Madigan: --You do not have a privacy interest in contraband, as this Court has recognized in the Jacobsen case.
Justice Kennedy: Yes, but you have a privacy interest in your person and in your place, and that's what we're talking about.
So that seems to me that that just doesn't help us.
Ms Madigan: Well, there is a distinction that's made in terms of Fourth Amendment protections that are given to homes and people versus cars.
Ever since the Carroll case, it has been recognized that a warrantless search of a car can be done if they found probable cause.
Justice Kennedy: But that's because of the nature of the place being searched not because of the nature of what you're searching for.
Ms Madigan: Correct.
Justice Scalia: Not necessarily.
Justice Kennedy: So it just can't be that... so the fact that you don't have a privacy interest in contraband, it doesn't seem to me... I... I don't think you need that argument.
Justice Scalia: I think you should use it.
[Laughter]
Ms Madigan: I... I plan on continuing to use it.
Justice Scalia: Why... why do you... are you sure that Kyllo, you know, the... the imaging case, would have come out the same way if the only thing... the only thing... that the imaging could pick out is not any of the other private activities in the home, but the only thing it could possibly discern is a dead body with a knife through the heart?
Are you sure the case would have come out the same way?
I'm not at all sure.
Ms Madigan: I would hope the case would come out differently than--
Justice O'Connor: Well, what--
Justice Kennedy: Do you have any authority for that other than Justice Scalia's speculation about how this--
[Laughter]
--how his Kyllo case might have been written?
Justice O'Connor: --What about a house and... and the use of a dog to sniff around a door access or a house just because the police think, you know, it's possible this is somebody growing marijuana in the basement or something?
Is that all right?
Ms Madigan: --I would argue that, yes, it is all right to walk a dog around a house, but then as Justice--
Justice O'Connor: How do you... how do you reconcile that with the heat sensor case then?
Ms Madigan: --The thermal imager that was used in the Kyllo case was able to reveal intimate details of the house.
A dog sniff is only going to reveal the presence or absence of contraband, and because of that, that's where we suddenly get into the tension between Kyllo and Place and--
Justice Stevens: What if the dogs get a little more sophisticated in the future and can also smell a certain kind of perfume, something like that?
Would then the whole analysis change?
Ms Madigan: --Well, then you would end up in a situation as to whether or not an officer had probable cause when a dog, in fact, alerted.
If he was alerting to the presence of perfume as opposed to narcotics, there--
Justice Stevens: And how would you know whether the... the dog... I don't think the dog alerts, as I'm alerting, for one reason or another.
He just alerts.
Ms Madigan: --Well, they're very well trained dogs.
In fact, in the State of Illinois, the dogs and their handlers go through 320 hours of training, and they're specifically trained to only alert to narcotics.
Justice Stevens: I just learned this morning that some very well trained dogs that are trained to alert for explosives will also alert for certain kinds of rubber in a tire.
They didn't realize that.
And I think it's entirely possible that dogs would... there will be false alerts by... by dogs because it's triggered by something that... that is not really anticipated.
Ms Madigan: One of the things that does take place during the training of these narcotics-detection dogs is to make sure that they are not alerting to things that are not narcotics or... I don't know exactly how the explosive training is conducted because we don't train our dogs in Illinois for explosives, but they purposely train them on narcotics not to alert to plastic wrap that is frequently the container used for narcotics, not--
Justice Stevens: So you would agree the analysis would be different if there could be an innocent cause of the alert as well as the contraband being the cause of the alert.
Ms Madigan: --It depends.
The analysis would be different if the dog was known to or had been trained to actually alert to the non-contraband.
Justice Scalia: Or if that happened a large percentage of the time.
I mean, surely you'd concede that the search is unreasonable if, for every... every one time, you... you make somebody open his bag because the dog actually smells narcotics, 99 times you make somebody open his bag because he has apples in it.
I mean, wouldn't that go to the reasonableness of--
Ms Madigan: Well, it would actually go to whether or not that dog provided... that dog's alert provided probable cause to conduct a search.
Justice Kennedy: Well, do we... we don't have the probable cause question before us, do we?
Ms Madigan: You do not have the probable cause question before you.
This dog was determined to be reliable by the trial court and the Illinois Appellate Court, and it was not part of the Illinois Supreme Court's decision.
Justice Breyer: What again in your view is the best distinction from Kyllo?
Ms Madigan: Two things.
One, the thermal imager used in Kyllo was able to reveal intimate details that individuals--
Justice O'Connor: Like what?
I thought it was just heat?
Justice Scalia: --Yes.
Ms Madigan: --There was some disagreement on the Court about exactly what it revealed, but in terms of intimate details, it then allowed somebody--
Justice O'Connor: Excuse me.
What details?
It is a device that measures heat.
Ms Madigan: --Because it could measure heat, it could also potentially determine when somebody was taking a bath, taking a sauna, and doing other intimate things in the house.
Justice Ginsburg: I think there was a reference to my lady's bath in the opinion.
Justice Scalia: A nice turn of phrase, as I recall.
[Laughter]
Justice Breyer: What was... and what was the second?
Ms Madigan: The second one would be the distinction between houses and cars and the protections that houses are given under the Fourth Amendment, which are far greater than the protections that people have in their cars.
Justice Kennedy: Well, so you think if this were a house, that the Kyllo case would apply?
Ms Madigan: If this were a house in the situation, it would certainly bring out the tension between Kyllo and Place--
Justice Scalia: Wasn't there... didn't Kyllo... wasn't what... what the Court was worried about in Kyllo not just the relatively crude heat imaging that existed in the case before it, but the prospect of more and more sophisticated heat imaging which... which we had evidence was already in development that would enable you to see people moving around a room?
I thought the case referred to that.
Now, are we going to have more and more... what's going to happen with dogs?
I... I can't imagine that... that this thing is going anywhere other than smelling narcotics and smelling bombs.
Justice Stevens: Well, but you would argue that the same rationale should apply if, instead of using dogs, you had some sophisticated device that would buzz or ring a bell or something whenever the odor of... of narcotics was present, wouldn't you?
Ms Madigan: --I would argue that.
So if there was an ability to create a... a mechanical dog, for instance, we would again say that the use of a mechanical dog sniff would not be a search and therefore would not--
Justice Stevens: There's nothing magical about the fact that it's an animal rather than a sophisticated device.
It has better detection capacity than a human being does.
That's the only difference.
Ms Madigan: --You are correct.
Justice Souter: In... in discussing the... the answer to the... the Kyllo issue, you... you place an emphasis on the protection given to a house.
Would you go back to Justice O'Connor's question and my earlier example?
Is it still your answer that the police can walk dogs around the foundation of the house or take a dog to the front door and ring the bell and see what it... what it sniffs when the door is opened--
Ms Madigan: I would--
Justice Souter: --without there being a search and hence no Fourth Amendment concern?
Ms Madigan: --Yes, Justice Souter, I would say that that is possible because the sniff itself is not a search and it only reveals the presence or absence of contraband, which is something that the individual does not have privacy expectations--
Justice Souter: Okay.
But then... then the... then there is no significance in the house.
Ms Madigan: --There is potentially significance in the house because the--
Justice Souter: Well, when does... when does it occur?
I mean, if... if... first you say the... the house is... is a matter of significance for Kyllo analysis.
We're trying to draw a distinction, if there is one, between Kyllo and this, and you say they can go to the house.
They can sniff the foundations.
They can go to the front door, et cetera.
I don't see that the house, in fact, is functioning as a distinction at all.
Ms Madigan: --This Court's precedents have shown us that in fact Fourth Amendment protections are higher in the home than they are in the car.
Justice Souter: Oh, I realize that, but it seems to me your basic argument, if I understand it, is there is simply no search here, and because there is no search here, it doesn't matter whether you're dealing with a house or a parking lot or a car on the road.
No search is no search.
So for purposes of... if I... I want to understand your case, and as I understand it, for purposes of your case, there is no significance in the house because there doesn't have to be.
The question doesn't arise because there's no search.
Is that--
Ms Madigan: Justice Souter, that is absolutely correct.
A search, as far as we are concerned... and I believe it's based on the precedents of this Court... is a sniff is not a search, and therefore it requires no Fourth Amendment justification.
Justice Ginsburg: You said there's no disturbance of one's privacy and so that distinguishes the dog sniff from some other governmental intrusions.
But dogs can be frightening, humiliating.
It seems to me that there is some association with the idea that I have a right to be let alone by my government and having a large dog circle my car.
Ms Madigan: There are in this country millions of dogs, many of the types of dogs that are used by narcotics detection teams, such as Labrador retrievers and shepherds, are identical to the pets that people own.
We encounter them in the parks, on the streets, and I would contend that an officer cannot be in the position of making a determination as to whether or not the individual that he encounters is going to be frightened by the dog.
Mr. Justice Stevens, if I may, I'd like to reserve the remainder of my time.
Justice Stevens: Yes, you may save your time.
Ms Madigan: Thank you.
Justice Stevens: Mr. Wray.
Argument of Christopher A. Wray
Mr. Wray: Justice Stevens, and may it please the Court:
There's no dispute that respondent here was lawfully stopped based on probable cause.
There's also no dispute that the entire stop took less than 9 minutes.
The question is whether a second officer's use of a drug dog to sniff outside of that car during those 9 minutes required some separate Fourth Amendment justification.
Justice Scalia: Do you agree with... with General Madigan that it doesn't make any difference whether the... the dog is a... is a mechanical instrument or not?
Do you agree it makes no difference?
I thought that one of the... one of the points in... in the imaging case was that this was a new technology which didn't exist and that although the ordinary rules in 1791 was that there was no search unless... you know, unless you enter the house or unless you... you physically intrude upon the person's... at least the person's clothes, we made an exception to that rule because of this new technology that enabled you to find out things without having to intrude into the home or into the person.
Now, but... but this is not a new technology.
This is a dog and... and they had that ability in 1791 just as they had it today.
And the rule that when there's no intrusion, there's no search... there's no reason to depart from that rule with respect to a dog although there would be with respect to some sophisticated new technology that would enable you to find out all sorts of things.
Mr. Wray: That's correct.
Justice Scalia: It seems to me you shouldn't... you shouldn't assume that... that the fact that this is a canine makes no difference.
Justice Stevens: Are you going to rely on the fact that dogs were trained to do this sort of thing back in the 18th century?
Mr. Wray: I'm going to rely on... on three distinctions between this case and Kyllo, Justice Stevens.
The first is that the three points that the Court looked at in Kyllo were: one, as has already been referenced, the fact that it's a home, the most sacred place under the Fourth Amendment; second, that it revealed certain intimate details; and third, that that was a technology--
Justice Stevens: It was potentially revealed.
It did not actually reveal any details.
Mr. Wray: --As... as General Madigan referenced, there is obviously some disagreement within the Court on that issue, but the... the fact was that the technology in Kyllo revealed information about heat in the house which could be thought to reveal intimate details about the house.
The third point in Kyllo, which I think Justice Scalia is referring to, is that that was technology that was not in general public use.
Dogs have been used by law enforcement across the country since Place and before to sniff everything from--
Justice Stevens: But not in 1790.
Mr. Wray: --Not--
Justice Kennedy: Did you come here--
Justice Scalia: You don't know that, do you?
Justice Kennedy: --Did you come here having researched all about dogs in 1790?
[Laughter]
Mr. Wray: --Justice Kennedy, I cannot, I regret to say, tell you what dogs were doing in 1790.
I can tell you... and this is maybe a factual thing that might be of interest to the Court... that the dogs who train... who are trained to alert to detect things... it's not that they are sniffing things that all dogs can't already smell.
It's rather that they are trained to let the handler know that they've smelt whatever it is they've been trained to smell.
So the smells that are coming out of Respondent Caballes' car are exposed to every dog.
Justice Stevens: But do you really think this would be a different case if the officer had a device that did exactly what the dog... dog did?
Mr. Wray: We... our position would still be, Justice Stevens, that as long as the device only revealed, as this does--
Justice Stevens: I would think you'd take--
Mr. Wray: --the absence or presence of contraband, it would still be constitutional.
Justice Souter: Why do you rely on the... in... in distinguishing Kyllo, why do you rely on the house if there's no search?
Why do you have to rely on the fact that there was a house involved there?
You... you listed that as one of your three distinctions.
Mr. Wray: We don't believe we have to rely on it, Justice Souter.
We do believe that there were three things that were important in Kyllo.
The fact that it was a home was one of those things.
Again, the... the fact of a home, the fact that it was technology not in general public use, and--
Justice Scalia: But that didn't go to whether it was a search or seizure.
I think it goes to whether it was an unreasonable search or seizure.
Don't you think so?
That what... what might be unreasonable with respect to a home would not be unreasonable with respect to a suitcase?
Mr. Wray: --Yes, Justice Scalia, that's correct.
Justice Souter: But... but your... is... is it... I understand it to be your position that there simply is no search here.
Period.
Mr. Wray: That is correct, Justice Souter.
Justice Souter: Because it's a dog sniff.
Mr. Wray: We would... we would submit this is not a search because, as this Court recognized in both Place and Edmond... and the Jacobsen case is also significant because the Court said that the reason this is not a search, there using the dog sniff by analogy, is because it compromises no legitimate privacy interest.
The language of the Court in Place is significant because it says that we are aware of no other investigative procedure that is so limited in both the manner in which the information is obtained and in the content of the information revealed.
That language goes not only to why it's not a Fourth Amendment search but why the use of the dog sniff during a probable cause traffic stop here, where it doesn't prolong the duration, does not transform an otherwise lawful seizure into an unlawful one.
Justice Souter: All right.
Do you... do you think it's... it's reasonable to say that if the police take dogs simply onto private property to sniff the foundations of houses, if they take dogs to the front door and ring the bell so that they hope the door will open, that there is... there is no compromise of a privacy interest?
Mr. Wray: Well, there would be a question as to whether the officer, the human officer, that is, could be on private property... I take it from your hypothetical, Justice Souter... in the first place.
But--
Justice Souter: Well, I mean, the Fourth Amendment analysis after Katz doesn't... doesn't depend on trespass, and... and you have said up to this point that there is no search.
And then you have quite rightly said that we have had as a consideration in our minds analytically whether it's fair to say that what the police were doing involved any compromise of a privacy interest.
So I'm assuming... I'm assuming that the police can at least get to the foundation with a dog and they can certainly walk up to the front door and ring the bell.
And if they do that with a dog, for the purpose of letting the dog sniff and alert, if there's anything to alert to, is it fair to say that there is no compromise of the privacy interests of the people who own the house?
Mr. Wray: --Our position would be... the answer to that question is yes.
The Court does not have to resolve that issue to decide this case.
Justice Scalia: Of course, we could separate the home from the... from what happened here and still validate the search here if we held that it was a search, but was a reasonable one since all you find is that the person was carrying contraband.
It's the only thing that's disclosed.
Whereas, if you... if you did the same thing with... with regard to a house, which is a more sacrosanct part of one's privacy, it might be an unreasonable search.
We... we could reach that result if we wanted to, couldn't we?
Mr. Wray: I think you could, Justice Scalia.
It's important to distinguish--
Justice O'Connor: On the other hand, if it were a drug-selling neighborhood or around a park where drugs are frequently sold, would it be legitimate in your view for the police to take drug-sniffing dogs and walk around the public street where cars are parked around that known drug-selling area and see if they could sniff out some contraband in the cars?
Is that okay?
Mr. Wray: --We believe it would be okay, Justice O'Connor.
It would be important not to use the dogs in a way to constitute a new seizure because in that case, you're not talking--
Justice O'Connor: I'm... I'm assuming parked cars.
You haven't interrupted anybody.
Nobody is in the car, parked on a public street.
Mr. Wray: --In that instance, we believe that would be acceptable under the Fourth Amendment.
Justice Kennedy: So you... you give no significance to the fact that this dog sniff was in the course of a lawful stop where the citizen's rights had already been curtailed to a significant extent?
Mr. Wray: We believe, Justice Kennedy, that the... that that context here makes this an even easier case under the Fourth Amendment, that is, the dog sniff not being a search compromising no legitimate privacy interests during the course of a lawful probable cause stop, which we know from Atwater... the officer could have simply placed the woman under full custodial arrest and taken her down to jail... was not an activity that transformed the seizure into an unlawful one.
The Illinois Supreme Court's concern and where we think they got off track was that they were concerned that the use of the dog sniff during this 9-minute traffic stop was that it transformed it... it used the language that it transformed the sniff into a drug investigation.
We would submit that the Fourth Amendment is about the reasonableness of searches and seizures and not about what the scope of the government's investigation is.
And in that sense, the court got off track.
These... this is a... this is a means that law enforcement has been using properly in reliance on this Court's decision in Place, reinforced just 4 years ago in Edmond, for more than 21 years to detect everything from drugs to bombs to smuggled... we have beagles in the airports that smuggle produce that's being smuggled in.
Dogs are used all over the country with great effectiveness in law enforcement, and the... we... that is a... a technique that we want to encourage law enforcement to pursue.
Justice Ginsburg: Are there... are there any manuals for law enforcement officers with respect to the time and place of using dogs, or it's just open season?
Mr. Wray: Justice Ginsburg, there is extensive training of law enforcement to use dogs.
It's a multi-week program that requires--
Justice Ginsburg: I don't mean the training to make the dog alert properly.
How the police will use them, when, under what circumstances.
Mr. Wray: --Justice Ginsburg, each agency has different policies about when they use dogs and what purpose they're trained for.
In this case, as you heard, they're being used in the context of highway interdiction, and so they're trained to sniff around vehicles specifically.
Justice Stevens: --Thank you, Mr. Wray.
Mr. Wray: Thank you.
Justice Stevens: Mr. Meczyk.
Argument of Ralph E. Meczyk
Mr. Meczyk: Justice Stevens, and may it please the Court:
The State does not offer any Fourth Amendment justification whatsoever in regards to... in this case.
It argues instead that there... there was no need for any justification, and that is incorrect for two reasons.
The dog sniff in this case invaded a Fourth Amendment interest of Mr. Caballes in the context of a routine traffic search.
The sniff in this case was, in fact, a search.
Albeit it was a limited intrusion, it was still a search nonetheless.
Justice Scalia: Why... why do you say that?
I mean, is... is anything that I observe a search?
I mean, suppose I... I'm a policeman and... and I'm looking out for, I don't know, people with a nervous tic because I think that that might be somebody who's about to commit a crime or has committed a crime.
Have I searched that person because I... I observe something external?
Mr. Meczyk: Any observation I think--
Justice Scalia: Is there no difference between an investigation and a search?
Mr. Meczyk: --There is in this case... see if I understand you correctly.
Justice Scalia: No.
It seems to me your brief and... and your statement here both seem to assume that there's a search whenever the police investigate.
Mr. Meczyk: Well--
Justice Scalia: But that's not so.
They... one can investigate without searching.
Mr. Meczyk: --Well, to... see if I understand your question correctly.
If you're looking with someone with that nervous tic, that would be something in open view or plain view.
That's not the type of investigation I'm talking about.
There is in fact, most respectfully, an investigation technique here.
There's an investigation measure.
Justice Breyer: Yes, but that isn't the--
Justice Kennedy: What about a policeman who smells marijuana coming out of a car or a residence.
He's walking down the street, public street, and he smells marijuana.
Mr. Meczyk: The only way I can analogize that, Justice Kennedy, is that it... that is akin to a plain smell or plain view.
Justice Breyer: --All right.
So once you say that, you realize that there are billions and billions of searches that go on every day that the police don't have to justify at all.
They just look around.
Mr. Meczyk: I don't--
Justice Breyer: Okay?
There are billions of them.
So the real question is do they have to give a justification for this.
And the argument that they don't is simply that it's not in the person's house.
When you go out in a public place, even in your car, you might run into people or animals with sharp noses.
And a lot of them can detect marijuana.
And you know, maybe it's a Limburger cheese.
I don't know.
[Laughter]
But people are sniffing things that they don't sniff through windows into your house, but they do get odors in your car on the street.
So this is the kind of search.
Yes, it's a search, but one that the police don't have to justify.
Mr. Meczyk: --But this is with a specific investigative tool.
Justice Breyer: Well, it's a specific investigative tool when I put on my glasses to look through a window.
Mr. Meczyk: Well, this is--
Justice Breyer: I don't see why it has to... why that matters if in fact all... if you go into a car, a police car, and you have... drive through the neighborhood and look around, you are using a specific investigative tool, the police car, to look around and find out what's going on.
Mr. Meczyk: --This is a far more... most respectfully, this is a far more sophisticated investigative tool.
Justice Breyer: What I'm trying to get to is in my own mind it's not a question of the tools.
It's a question of the expectation of privacy.
Mr. Meczyk: Then maybe I can see if I could answer your question.
Mr. Caballes in this case indeed had an expectation of privacy.
When he was asked by the police officer in this case if he can consent to the search, he said no.
He did not want that law enforcement officer looking in--
Justice Kennedy: But that never--
Justice O'Connor: Yes, but both Place and Edmond, opinions from this Court, said sniffs are not searches.
Mr. Meczyk: --Well, I--
Justice O'Connor: Do you want us to reverse that?
Mr. Meczyk: --Justice O'Connor, I do not... I do not want you to reverse Place.
Place, no pun intended--
Justice O'Connor: Well, and Edmond also said it's not a search.
Mr. Meczyk: --Well, there were--
Justice O'Connor: It was the stop of the cars in that case that caused the result.
Mr. Meczyk: --The way I understand Place it was contextually limited.
In Place, the whole purpose of the seizure, the taking of the luggage, was to submit it to a drug-detection sniff.
That is the opinion authored by Your Honor, that specifically stated... I'm not going to say took for granted, but it specifically stated that the... the context... and that's what we have to look at Place... the--
Justice O'Connor: Well, fine.
We had a context there where we supported it, but in the process said the sniff, the dog sniff, was not a search.
Mr. Meczyk: --Well, I... I--
Justice O'Connor: So you want us to say something else here.
Mr. Meczyk: --Well, I think that first in... in that case, in Place, the... the Court--
Justice O'Connor: The context here was a legitimate traffic stop.
Mr. Meczyk: --But it was... unlike Place, the legitimate traffic stop here was completely unrelated to the purpose of the dog sniff.
There was an absolute--
Justice O'Connor: The dog sniff is not a search.
What difference does it make?
Mr. Meczyk: --Well, again, I would again respectfully assert that the dog sniff is a search and the way Place was decided, first, the decision had to be made, in the context of... of that case, what was worse.
What were they going to do with the luggage?
Were they going to open the luggage first?
So, of course, the Court had to decide in that case that it wasn't that kind of a... a search.
It wasn't as egregious a search as actually opening the luggage.
Then you--
Justice O'Connor: This... the trunk of the car didn't have to be opened here.
Mr. Meczyk: --I'm sorry, Your Honor.
Justice O'Connor: The trunk of the vehicle did not have to be opened here.
You're talking about a dog sniffing on the exterior of the vehicle that was legitimately stopped for a traffic violation.
Mr. Meczyk: Again, in this context, unlike in Place, there was absolutely no relationship between the... the dog sniff and the dog sniff of Caballes' trunk and the sniff of the luggage that was placed at LaGuardia Airport in Place.
There's a great distinction.
Moreover--
Justice Scalia: Suppose a policeman follows me around.
He just... just follows me around, observing with his... with plain eyes.
Now, is that a search?
Does he need probable cause to do that?
Now, he's wasting his time and he's wasting public money and maybe he should get fired for doing it, if he has no reason to follow me.
Mr. Meczyk: --It's not a search.
Justice Scalia: And maybe... maybe I'd have a harassment action against him if he does it, you know, blatantly.
But is that a search?
Mr. Meczyk: It is not a search.
If he follows you--
Justice Scalia: Okay.
So... so the mere fact that one is in investigating something doesn't make it a search.
What does make it a search?
Mr. Meczyk: --Well--
Justice Scalia: The fact that you find out something?
Mr. Meczyk: --I think here the most distinctive point here is that Caballes had already been stopped unlike the hypothetical that you just presented to me.
Caballes was already stopped for one... for probable cause.
There's no question about that.
But then now the police launch into a wholly unrelated investigation that's--
Justice Scalia: You think it would be better if he hadn't been stopped?
If... if they just... just randomly walked up to somebody who was going through a toll booth and had the dog sniff the car, you think that would be a better case--
Mr. Meczyk: --I think--
Justice Scalia: --for allowing it than... than yours?
Mr. Meczyk: --Even in that case, even in a hypothetical where they used the dog for a toll booth, I have a problem with that.
That to me is a search.
It's different than... I would assert it's different than if they walked... one of the hypotheticals that the Justices asked my adversary in this case, when they asked, well, what if they walked the dog instead around a... parked cars or parked cars at a stadium?
It depends for what purpose they want to walk those parked... that dog around those parked cars.
My assertion is--
Justice Ginsburg: Well, they said it's to find out if there's any contraband.
Mr. Meczyk: --I'm sorry, Your Honor.
Justice Ginsburg: The answer was they are at liberty... the police are at liberty to use dogs to find contraband.
And your... Illinois I think was very candid with the Court in saying we have taken from your decisions that a dog sniff is not a search.
So anything else is a matter of police policy.
It had nothing to do with the Fourth Amendment.
Mr. Meczyk: Well, I... I strongly differ.
I have to look at the purpose that they are going to use the dog for.
This Court--
Justice O'Connor: Well, does it matter if, for instance, in today's world on Capitol Hill we're concerned about terrorist attacks.
What if the dog is trained to alert to explosives?
Now, can the police just decide they're going to sniff any car that's parked on Capitol Hill?
Mr. Meczyk: --Justice O'Connor, it depends on the purpose.
Justice O'Connor: Yes or no, in your view.
The purpose is to disclose potential explosives in a parked vehicle.
Mr. Meczyk: The answer is yes.
I have no problem whatsoever.
Justice O'Connor: Wherever it is.
Mr. Meczyk: Wherever it is because I look at it as a public safety exception.
And this Court in the Edmond case specifically condemned a general search... a general crime... let me use the exact words.
General interest in crime control, to quote the Edmond case.
And that's--
Justice Breyer: I still want to go back to my question because I think you may have an answer to it and I want to focus you--
Mr. Meczyk: --I'm struggling, yes.
Justice Breyer: --I want to focus you on the question.
I think what you're doing, which is a reasonable thing to do, but it isn't my approach, look to the English definition of search.
I say forget that.
Let's look to the Fourth Amendment because there are a whole range of searches that don't even fall within the Fourth Amendment in the sense that we don't need a justification.
And I take Place as saying that dog sniffs is one of those, whether it does or doesn't use the word English search.
So I want to know why it is that this dog search is one of the ones that's a Fourth Amendment search, i.e., one of the ones that requires a justification in terms of what the Fourth Amendment is about, privacy.
Mr. Meczyk: It invades a public... I'm sorry.
It invades a private space that in this particular case the respondent Caballes had a privacy interest in, that he wanted to exclude the whole world from going inside his trunk.
That's the difference.
Justice Stevens: Yes, but you don't respond to one point in Place, if I remember correctly.
It must be a legitimate expectation of privacy, and if the only thing the dog can detect is something illegitimate, how can you say there's an invasion of a legitimate expectation in privacy?
Mr. Meczyk: Well, it is... it's true that one does not have an expectation of privacy in contraband, but by the same token, I have an expectation or Mr. Caballes had an expectation of... of privacy of what's inside that closed trunk, his car.
The Carroll doctrine is still good law.
We still apply the Fourth Amendment in cars.
It's true that the home is sacrosanct, but just because it's a home, it's not a talisman where... where the Fourth Amendment no longer applies.
Justice Ginsburg: There was something you said in... in your brief that I thought was unclear.
So may I ask you--
Mr. Meczyk: Of course.
Justice Ginsburg: --if Officer Gillette, the one who did the arrest for speeding, had a dog in the back of his car, instead of having the second officer come with the dog, would it have been permissible?
I thought you had conceded that it would be a different situation if the dog was already there when the car stopped.
Mr. Meczyk: First of all, Justice Ginsburg, my recollection is that Trooper Gillette, who was the officer who stopped Caballes, did not have a... a dog in the car.
Justice Ginsburg: No, he didn't, but I'm asking you to imagine that he did.
Mr. Meczyk: I see.
If he had a dog in the car and the dog just happened to have alerted without his cuing the dog or walking the dog... and I'll answer that in a moment too... that would be pure serendipity.
That might happen.
If... if the dog just happened to have alerted.
But if the troopers deliberately drove the car close by... and in reality, that's not what happens.
Justice Ginsburg: No.
I would like to take this scenario as it is except that when the officer gets out of the car, his dog comes with him.
Mr. Meczyk: Okay.
Justice Ginsburg: This is very... make no other changes except that Gillette has the dog and Gillette with the dog go to Mr. Caballes' car.
Mr. Meczyk: My understanding of the way this works, Justice Ginsburg, is that he just couldn't go up to the car without... and the dog would alert.
My understanding of the way these dogs are trained is that they specifically... that the officer has to walk the dog around the car, the vehicle, first of all.
Justice Scalia: He does that.
He does that.
Mr. Meczyk: He does that.
Justice Scalia: Yes, in this case.
Mr. Meczyk: He does that.
Justice Scalia: Right.
Mr. Meczyk: To cue the dog.
In other words, tell him it's not playtime anymore, that he has to work.
Justice Scalia: Right.
Mr. Meczyk: To trigger something in the... in the canine brain.
Justice Scalia: Right.
Justice Ginsburg: But you... I'm--
Justice Scalia: Would it be bad?
Would it be bad if that's what he did?
Mr. Meczyk: It wouldn't be bad that's what... well, yes.
In this case it's very bad because it's a search.
There's no question.
I'm not coming off of that.
Justice Ginsburg: --But I'm... I'm trying to understand what you meant in your brief when you said if the dog had been in Gillette's car when Gillette stopped Caballes, the situation would have been different.
Mr. Meczyk: I... I think what I meant there... there would have been... it would have been purely happenstance, almost like plain view.
It would have been... without him even cuing the dog or starting to walk the dog around, my answer to that Justice Ginsburg is that that would have been all right.
Except now that... the more I think about it, I'm not so sure that it would be all right.
And my answer to... and the reason for that is I think in that case the officer, if he could do such a thing and the dog would alert, would be exploiting the situation, would just be taking the dog and walking him around the car and seeing that the dog alerted.
So in other words, there... there would be, I think, an exploitation of... of the... of the traffic stop.
Justice Ginsburg: So then it really makes no difference whether it was Gillette who had the dog in his car or whether the dispatcher called another officer who had the dog.
Mr. Meczyk: That is correct, Your Honor.
Justice Ginsburg: It doesn't... so you're retracting that.
You, I think, were asked but I'm... I'm not sure you fully answered.
Suppose the police, as Atwater would allow, arrested, made a full arrest of Caballes, and then they impound his car.
In the place where they put it, couldn't they have a dog go around the car there?
Mr. Meczyk: Yes.
Yes.
I... if we had an Atwater situation... in this case there wasn't an Atwater situation because there was first a warning given.
You're correct.
There was a warning given.
I'm sorry.
The officer Gillette told Caballes he was going to give him a warning.
So unlike the Knowles--
Justice Ginsburg: But he could have.
He could have.
I mean--
Mr. Meczyk: --He could have, but he didn't.
Justice Ginsburg: --is... is--
Mr. Meczyk: He didn't.
Instead, he chose to treat this as more of a Knowles situation.
This case is... is on all fours, no pun intended, like Knowles.
In other words, in the... in Knowles v. Iowa, the Court... a case of this... I'm sorry.
Let me untwist my tongue.
In Knowles v. Iowa, you had a... you had a traffic stop and after the traffic stop, there was a statute that said unrelated to the traffic stop, you can go in and search.
And this is the same thing.
This officer here Gillette treated Caballes as the officer in Knowles in... treated Mr. Knowles in Iowa.
It's the exact same thing.
Justice Souter: No, but the... the difficulty that I have with that argument is take the... take the case of... of the arrestable offense in which it is undoubtedly the case that although the police don't normally arrest, they... they can.
Your... if I understand your argument, you're saying if they, in fact, do arrest, they may then take the dog around the car, and indeed, I presume you would agree, they could make an inventory search because they've got to protect themselves against claims that they lost property and so on.
So there's no question that in that case, as... as you have argued it, they could make a full-blown search and... and certainly can use the dog.
But if they choose not to arrest on the highway, they can't.
My problem is how can you say that there is a reasonable expectation of privacy in case number two if you admit that the police can search in case number one.
How does that affect the reasonable expectation of privacy?
Mr. Meczyk: To me, once a person is told that he is not going to be under arrest, it changes the whole complexion of the case.
I think it's a completely different... a completely different scenario.
We don't have an arrest.
It doesn't matter.
Atwater--
Justice Ginsburg: --Could the officer change his mind?
I mean, he... he did say I'm just going to give you a citation, and then he said, mind if I search your car.
This is before the... the dog showed up.
And suppose the person who had been speeding said, yes, I mind.
Don't search my car.
And then the police said, well, in that case I'm going to arrest you.
Mr. Meczyk: --It's a difficult question, but I have to look at what... I think reasonableness is judged.
Again, I'm going to remember what the... those cases taught.
I think what Knowles taught, that reasonableness is judged by what the police actually do as opposed to what they might have done.
Justice Scalia: Mr. Meczyk, I assume that your answer to whether it's lawful to have a... a dog at a bus depot just to sniff the bags of people who were coming off, without stopping them, but just... just to have the dogs there, that's unlawful.
Mr. Meczyk: It depends--
Justice Scalia: For narcotics, not for bombs, not for... just... just for narcotics.
The police think, you know, a lot of narcotics goes on interstate buses.
We're going to put a dog in the bus depot.
Mr. Meczyk: --It's a little less problematic to me, Justice Scalia, than the type of stop I'm talking about here.
Justice Scalia: Why?
Mr. Meczyk: It's a little less problematic.
One, because it's a public place and I... I think--
Justice Scalia: Well, so is the road, for Pete's sake.
Mr. Meczyk: --I know, but... but here I think there's a lesser expectation of privacy.
Well, I don't even want to go that far.
I... I have to answer your question.
I think that submitting the dogs without any... submitting the luggage without any reasonable articulable suspicion--
Justice Scalia: Right.
Mr. Meczyk: --unlike the case--
Justice Scalia: Right.
Mr. Meczyk: --unlike the case in... in Place, that that to me is still a search.
So--
Justice Scalia: Okay.
That's... that's what I think you should say.
Mr. Meczyk: --And I am saying it.
Justice Breyer: Yes, but that isn't... I take it you don't--
Mr. Meczyk: Sorry it took me so long.
Justice Breyer: --Is there anything wrong with the policeman himself taking a sniff?
Mr. Meczyk: It goes back to--
Justice Breyer: It's the great Limburger cheese robbery.
[Laughter]
He stopped the car and he walks around.
Anything wrong with that?
Mr. Meczyk: --There's nothing wrong if he can detect Limburger cheese.
That to me is like plain smell.
Justice Breyer: All right.
Mr. Meczyk: As awful as that--
Justice Breyer: So plain--
Mr. Meczyk: --As awful as it might be--
Justice Breyer: --All right.
So... so what you're saying is... and this must tie back to reasonable expectation of privacy.
All right?
Because it's okay for the policeman to do it, and it's okay for dogs to do it in the bus station, and it's okay to use a dog not in the bus station with a car if in fact you actually are going to put him under arrest, although here you had probable cause to do so, I take it.
And now you have to draw a pretty fine line.
But it's not okay where it's not the bus station, but it is the car and in fact the dog is doing the sniffing... and there are a lot of dogs around that can sniff... and you did have probable cause but you didn't say it.
And in face of Justice O'Connor's case which said that... you see.
Well, I mean, this is... this is--
Mr. Meczyk: --I guess you--
Justice Breyer: --I mean, I'm not saying you couldn't draw that line, but I'm saying it's pretty tough I think.
Mr. Meczyk: --I guess you're telling me I'm... I'm the underdog in this case.
Justice Breyer: Well, I don't know.
[Laughter]
I'm right?
Am I... I mean, that--
Mr. Meczyk: It is--
Justice Breyer: --And you're going to draw the... well, I don't want you to repeat yourself necessarily.
Mr. Meczyk: --No.
It--
Justice Ginsburg: But you had already drawn the line at a different place than Justice Breyer suggested because in response to Justice Scalia, you said if it... if it were going into the bus terminal just to sniff for narcotics, unlike explosives, it would be an impermissible search.
Mr. Meczyk: --Yes, correct, Justice--
Justice Ginsburg: That would be--
Mr. Meczyk: --That is correct, Justice Ginsburg.
What makes this particular so--
Justice Souter: But... but is... why... why don't you simply say, look... have a very simple line.
If they can arrest, they can sniff.
If they can't arrest, they can't sniff without individualized suspicion going to drugs or whatever.
Mr. Meczyk: --I would agree with that if I use an... if... if you're referring to an Atwater type scenario.
If they have probable... if they decide to arrest, even though it's on a minor traffic case, such as Atwater, which was a seat belt, as long as it's... if... if it's minor and if the officer elects to choose to do a full-blown arrest, then all the consequences that follow from that arrest are... it's going to happen.
Excuse me.
It's going to happen.
Justice Souter: But what... what is the answer to the reasonable expectation to privacy question in that case?
Isn't your expectation of privacy identical, whatever it may be, or isn't the reasonable expectation of privacy identical, whatever that may be, without regard to the discretionary decision of the officer to arrest or not?
Mr. Meczyk: I... I think that when the officer does a full-blown arrest, as was envisioned in Atwater, you know that you... the person knows that he or she does not have a reasonable expectation of privacy.
Justice Souter: But you're saying that the... the reasonable expectation of privacy depends upon the officer's discretionary judgment whether or not to arrest.
Isn't that what you're saying?
Mr. Meczyk: Essentially yes, because I think that the officer takes a physical action.
It's just more than words.
It's also his deeds.
I think in Atwater, unlike Knowles... in Atwater, in that case, I think the... the officer did make an election, and there was a full-blown or a full-fledged arrest.
And I think there your... your reasonable expectation to privacy does, in fact, go out the window.
But this is so different.
This was just a warning.
Period.
It was nothing worse than a warning.
What makes this stop so pernicious is that it takes place in front of the whole world and is accusatory.
It is profoundly embarrassing, and it is humiliating to everyone on the street.
So if a person is stopped and the officer just decides to stop you for a minor traffic offense, that's the worst part about this case.
Just a minor traffic offense, really a frivolous offense, basically what any law-abiding citizen would happen to... it could happen to anyone.
And as this Court has said, even in Whren, there are so many multiple technical violations of... of... technical violations--
Justice Scalia: I mean, I think it's worse if... if you're subjected to it without having committed any violation at all.
Every time I travel abroad and come back into the country, customs officers have dogs and... and they parade the dogs through... through the baggage terminal.
Do... do I feel offended by that?
Mr. Meczyk: --No, Justice Scalia--
Justice Scalia: This isn't a public safety matter.
They're... they're not smelling for bombs.
They're... they're smelling for contraband.
And according to you, that is bad.
Mr. Meczyk: --That... in that situation, when you enter the country... and this Court has said many times again... it's a border search.
There's nothing that I can argue against the border search.
It's the... or the functional equivalent of the border.
That is a border search.
I bring luggage to the airport, in today's world I have a lesser expectation of privacy.
If I know I'm traveling abroad and coming into the United States, that's different.
That's different in an airport.
Justice Scalia: Okay.
A bus station is different, though.
Mr. Meczyk: A bus station here inside the United States is different I think.
I... I look at your airport hypothetical as being... as dealing with a border.
If it's not at a border and I use your hypothetical, it's at O'Hare Airport or Reagan International Airport and they bring a dog up to sniff for drugs at the carousel, that to me is a search.
It's like... I think you said in one opinion once if it... you used the duck analogy, well, if it walks like a duck or quacks like a duck.
Here it's still a search.
It walks like a... a dog and it acts like a dog, but its specific function is in fact to search out in public and humiliate people.
If there are any further questions.
I respectfully ask this honorable Court to affirm the wise judgment of the Illinois Supreme Court.
Thank you.
Justice Stevens: Thank you, Mr. Meczyk.
General Madigan, you have I think about 3 minutes left.
Rebuttal of Lisa Madigan
Ms Madigan: Thank you, Justice Stevens.
Let me make three brief points.
Number one, Justice Ginsburg asked a question about something that was in the respondent's brief, whether or not it made a difference if a dog was with Master Sergeant Gillette when he initiated the stop or if the dog was later brought, as was the case here, by Trooper Graham.
Really what Mr. Caballes is arguing for here is an inadvertence requirement which this Court very clearly held in Horton, there is no such requirement of inadvertence.
And so a law officer, if they are at a lawful vantage point, do have the ability to detect incriminating facts.
That is not something that has to occur inadvertently.
It can happen intentionally.
Second, Justice Scalia asked a question about plain view, and similar to plain view, a dog sniff does not effect an incremental search or seizure.
And therefore, similar to plain view, a dog sniff does not require Fourth Amendment justification.
And let me finally acknowledge something that Justice Souter brought up, which is whether or not, by walking a dog around a house, you in fact would have a search.
Let me... now, that is certainly a closer case than whether walking a dog around a car constitutes a search, which we say is not.
But ultimately you would reach a similar result because the principle is not going to extend to cars in the same manner in... in Kyllo as the thermal imager did.
Finally, if there are no further questions, we would ask that the judgment of the Illinois Supreme Court be reversed.
Justice Stevens: Thank you, General Madigan.
The... the case is submitted.
Ms Madigan: Thank you.
Argument of Justice O'Connor
Ms Madigan: I also have an opinion to announce in 03-923, Illinois versus Caballes that was authored by Justice Stevens.
This is a case that comes to us from the Supreme Court of Illinois.
In the opinion, authored by Justice Stevens, we answer a narrow question, whether the Fourth Amendment requires reasonable, articulable suspicion to justify using a drug detection dog to sniff a vehicle during a legitimate traffic stop.
An Illinois state trooper stopped petitioner Caballes for speeding on an interstate highway.
When the officer radioed the police dispatcher to report the traffic stop, a member of the State’s Drug Interdiction Team overheard the transmission and drove to the scene along with his narcotics-detection dog.
On arrival and while the first trooper was writing the warning ticket for speeding, the drug interdiction officer walked the dog around Caballes’ car, the dog alerted at the trunk prompting the officers to open the trunk where they discovered marijuana.
Caballes was arrested and charged with a narcotics offense.
The trial judge denied the motion to suppress the seized evidence.
The court found no Fourth Amendment violation because the officers did not unnecessarily prolong the traffic stop in order to conduct the dog sniff and because the particular dog sniff was sufficiently reliable to establishe probable cause to search the trunk.
The Illinois Supreme Court reversed.
In its view the use of a narcotics-detection cog converted the citizen police encounter from a lawful traffic stop into a drug investigation and because the shifting purpose was not supported by any reasonable suspicion of drug activity, it was unlawful.
We granted certiorari to review the Illinois Supreme Court’s holding.
We now vacate and remand.
In our view, conducting a dog sniff would not change the character of a lawful traffic stop unless the dog sniffs itself infringed unconstitutionally protected privacy interest.
Our cases made clear that it did not.
To fall within the purviews of the Fourth Amendment, police conduct must compromise a legitimate, interest in privacy.
Because a canine sniffs by a well-trained drug detection dog does not itself reveal noncontraband items and because any interest in possessing contraband cannot be deemed legitimate, the use of a properly trained drug detection dog during a lawful traffic stop will not generally implicate legitimate privacy interest.
In this case the traffic stop was lawful.
It was not prolonged beyond the time reasonably required to issue a warning ticket.
In these circumstances, a dog sniff that only reveals the presence of the substance no individual has any right to possess does not violate the Fourth Amendment.
Accordingly, the judgment of the Supreme Court of Illinois is vacated.
The case is remanded for proceedings not inconsistent with the Court’s opinion.
Justice Ginsburg and Justice Souter have filed dissenting opinions.