A Critical Look at United States v. Chatrie

Judge Lauck of Virginia’s Eastern District recently issued the much-awaited opinion. United States v. ChatrieHow the Fourth Amendment affects geofencing warrants.  This is my opinion, and it’s the first Article III court opinion. The Geofence warrants have raised some interesting Fourth Amendment questions, so we will likely hear more.  Here’s my view.

My response is unfortunately quite negative.   Judge Lauck took great care in this case and created an excellent record.  However, I think that the reasoning behind the decision is flawed.  Particularly, I doubt that execution of geofence warrants involves a Fourth Amendment Search.  If they do, I believe the Fourth Amendment standard to be a lot more strict than Judge Lauck has concluded it to be.

My concerns are explained in this post. First, I will give you a background about geofence warrants. Then I will go into the specific facts.   Next, I will discuss the reasoning of the court and why certain parts aren’t persuasive.  The Fourth Amendment’s application to geofence warrants is a complex issue. However, I do not believe this opinion is the best way to find out the answer.

I. Geofence Warrants: Background

Some context.  The majority of cell phones these days are connected to Google.  Google users are often using their phones to set up Google’s ability to find their location via a number of ways. This is a great tool to assist law enforcement.  Google might have information about the phones that were used to record a crime in particular places and times.

It is vital to be able to access Google data regarding location in order to generate leads when they are not available.  Google can track back the identity of criminals who had their phones on at the time they committed crime if the phone is set to allow Google to generate local information.

However, it’s impossible to be certain that this is the case.  The criminal’s cell phone is unlikely to be the only one in the area.  Google might also have information about other people in the vicinity.  Google location records could be very useful in generating leads.

Some specific details regarding how Google’s local service works are pertinent.  According to what I have read, ChatrieGoogle customers must sign up to enable Google services to store their location information.   Users who have opted in to location services may pause records from being created or remove records already existing, but they will need to be clear about this.  However, it’s unclear how simple this can be done at any time or how well this information is known by users.

If they don’t want location tracking to be tracked, users can turn off their phone or set it up in airplane mode.  Also, Google location information can be very precise and dynamic, showing where a phone was and where and how quickly it moved,  But the records can also be uncertain. Google may not know exactly where the phone is located. Instead of providing precise location information, it provides confidence intervals and only estimates.

Although it is not clear whether the search by Google for location data was a Fourth Amendment search, which requires warrants,  Google requires warrants in order to get this information. It has also specified three steps that investigators must follow to ensure the privacy and security of Google users.  The process could be challenged in court by an investigator, who would have to comply with Google’s warrant process and requirement.  There are practical reasons investigators have not done so, however. Google’s method has, for the moment at least, become the standard way that geofence warrants can be executed.

Google needs a warrant to access these location records. This has resulted in judicial decisions that only apply to warrants.  A few federal magistrate judges wrote opinions explaining their reasons for signing a geofencing warrant.  Now? ChatrieThe first instance in which legal questions are actually being litigated before an Article III Judge is this case. The suspect sought to suppress the evidence of the geofence warrant.

II.  II.

In this particular instance, the bank was robbed in Virginia in 2019.  He entered the bank and handed the teller an explanation of the crime. Then he showed his gun to the teller.  The victim was taken $195,000.  The police had no leads.  The suspect was carrying a cellphone with him and the government got a geofence warrant issued by a judge of the state magistrate to help identify him.  This warrant was issued to track down each Google-logged phone within 150 meters of the bank, from 30 minutes prior to the robbery through to 30 minutes afterwards.

The warrant was signed by a state magistrate, and Google advised law enforcement that 19 phones had responded to it.  Google provided location information to the government that showed where the phones were located over an hour. This included the time and date of their movements.  Google provided additional location data on 19 of its phones to the government. The phone’s whereabouts were revealed by Google for an hour prior and one hour following the incident.  The government now had precise tracking data on 19 of the devices, but not information about the owners.

After requesting the names of three phone owners, according to Google records, the government asked them for their identities. This was based upon the pattern of locations over two hours and the suspicion that the phone owner could have been the bank robber or one of his co-conspirators.  Google revealed this information. It showed that Okello chatrie registered the phone that was believed to be the victim of the robbery.  Chatrie was finally convicted for the robbery. Now, he is trying to hide the results of his geofence warrant.


First, the legal question is whether geofence information obtained is actually a search.  This issue will be litigated under a motion for suppression. The legal question is whether or not the defendant is entitled to standing. Were his records searched in accordance with Fourth Amendment law.  A motion to suppress must be supported by the defendant’s showing that his interest were searched.  See Rakas v. Illinois?, 439 US 128, 130 N.1 (1978).

It is not an easy issue.  The third-party doctrine states that voluntary disclosure of information is a waiver of a reasonable expectation for privacy.  Although this principle was not limited by the Supreme Court, it is still valid. Carpenter v. United StatesCell-site records could not be made because they were created by a person who was not willing to do so. To participate in modern living, you must use a cellphone. You can’t avoid creating location records for cell sites, as these are created automatically.

This raises the question of how this applies to Google’s location records. Users must affirmatively opt-in to Google to start, and they have the option to stop at any time, which they may not be able to do.  This is the context of CarpenterIs it possible to live modern life and not opt into Google’s location services?  Is it better to treat the creation of such records as voluntary since users can choose how they want them created or involuntary simply because some users don’t know that these records exist?

The ChatrieThis is not answered by the court unfortunately.  This is because the court decides for the government on the good-faith exception. It does not need to or will take a position about whether there was a search.  Instead Judge Lauck speculates on what the judge considers to be problems in current doctrine. He suggests that maybe legislatures should prohibit geofence warrants.

[T]It is troubling to the Court that other individuals than criminal defendants might be caught in expansive geofences and may not have any functional means of asserting their privacy rights. Imagine a geofence that includes a bank and church as well as a local residence and hotel. A criminal defendant would have no reasonable expectation of privacy regarding his or her activities inside or outside the public bank. United States, Knotts, 466 U.S. 276 – 281, 103 S.Ct. 1081. 75 L.Ed.2d55 (1983) “A person who travels in an automobile along public thoroughfares does not have a reasonable expectation that he will be protected in the movement from one place to another .”). He/she may therefore not be able establish Fourth Amendment standing in order to contest a bank’s time-limited acquisition his location data.

The individual living in the residence will likely not be there. We wouldExpect a greater level of privacy. Silverman v. United States, 365 U.S. 505, 511, 81 S.Ct. Silverman v. United States, 365 U.S. 505, 511, 81 S.Ct. [of the Fourth Amendment]You have the right to an [person]To retreat to his [or her].”).Unreasonable government intrusion in your home. This individual wouldn’t have known that law enforcement had gained private information about him or her, so the criminal defendant couldn’t assert his or her privacy rights. United States, Rumley, 588 F.3d 228, 206 n.2 (4th Cir. The warrant would have made it impossible for the innocent person to exercise any of his privacy rights. Geofence warrants can thus be used to infringe on “right without remedy”. Hawkins v. Barney’s Lessee 30 U.S. 457-463. 5 Pet. 457, 8 L.Ed. 1831 (“There is no remedy without right.”).

According to this Court, geofence analysis does not fall within the Supreme Court’s current “reasonable expect of privacy” doctrine when it comes to technology. This case is primarily about Tief, but perhaps not WidePrivacy intrusions. See, e.g., Kyllo v. United States, 533 U.S. 27, 34, 121 S.Ct. 2038, 150 L.Ed.2d.94 (2001), (considering whether thermal imaging can be used on one’s own home); United States, Jones, 565 U.S. 400. 402-03, 132 S.Ct. 945. 181 L.Ed.2d 94 (2001) (considering whether thermal imaging can be used on one’s home); United States v. Jones, 565 U.S. 400, 402-03, 132 S.Ct. [GPS]Tracking device to individual’s car” for twenty-eight day); Carpenter, 138 S. Ct. 2217 n.3; (considering whether or not “accessing seven days of [an individual’s cell site location information]It is a Fourth Amendment search.”

These issues should, at the core, be left to legislators. See Zach Whittaker, A Bill to Ban Geofence and Keyword Search Warrants in New York Gains Traction, TechCrunch (Jan. 13, 2022), (discussing a recently introduced New York bill that would ban the use of geofence warrants statewide). Because there is no law that prevents Google and its rivals from collecting this large amount of data, the case was brought to light. Google continues to make improvements, but it seems that it does so even though few people are able to disallow consent. Google’s consent flows are not understood by most users. Google logs user locations up to 240 times daily. Although it is beyond the Court’s jurisdiction to resolve such matters, it encourages legislative action. A thoughtful bill could protect privacy for citizens and relieve companies from the need to respond to law enforcement inquiries by police regarding the data that they have.

If this is taken to mean that you are answering the question, I find it difficult to understand how helpful it can be.

I believe that standing below is the most important question. CarpenterIs it voluntary to opt in to Google’s location services? If so, then the decision to allow Google to generate and store such records would be a third-party disclosure according to the third-party doctrine. CarpenterThey did not disturb.

It sounds quite voluntary to me if I have understood the explanation.  I find it hard to understand why Google’s location services would be necessary to engage in modern living. Carpenter standard.  If that’s right–a big if, perhaps, but run with it for now–then I would think that access to Google location services records shouldn’t be a search under the third party doctrine for any users. See my chapter for more details. Implementing Carpenter.)

Perhaps the record is in Chatrieeither the court is incorrect on this point or the court views the facts in a different way.  As a matter policy, I love the notion of mandating a warrant.  However, if I am correct in my interpretation of the facts, it is possible that the case will be closed on the basis that no search was conducted and therefore no warrant was needed.  How the  Fourth Amendment would apply if this were a case of secret tracking–which is what the court focuses on, looking to the idea that a perpetrator doesn’t have a reasonable expectation of privacy around a bank, but a person would in their home–doesn’t seem particularly irrelevant unless and until you deal with that issue.

However, this is an issue that I have no strong opinions about. I will admit it. CarpenterThis allows for some flexibility in meeting the voluntariness standard.  It wasn’t my idea. ChatrieThis issue was well addressed.

IV.  IV.

Now, let’s consider how probable cause applies.  What kind of probable cause is required to secure a geofence warrant?

Critically Judge Lauck states that the standard was probable cause Refer to the specific phones that were found within the geofence.   This means that the Fourth Amendment must be interpreted as requiring probable cause that any phone with records that are made public was, in fact, an individual evidence of the crime.

At base, probable cause demands that law enforcement possess “a reasonable ground for belief of guilt … particularized with respect to the person to be searched or seized.” Maryland v. Pringle 540 U.S. 336, 124 S. Ct. 755, 800, 157 L.Ed.2d 76 (2003) (emphasis in original); see Ybarra v. Illinois 444 U.S. 85.91, 100 S.Ct. 338, 62% L.Ed.2d 238, (1979). “Where probable cause is the standard, any search of or seizure must be supported with probable cause specificized with regard to that individual. The mere fact that a person is related to someone else suspected of criminal activity doesn’t give rise to probable cause for the search. Ybarra 444 U.S.A., at 91. 100 S.Ct. 338. . . .

Even though it is cloaked with the complexities of modern technology, this Geofence Warrant fails to provide sufficient probable cause. United States Supreme Court explains that warrants must prove probable cause “particularized in respect to the person being searched or seized.” Pringle, supra note 800 at 124 S. Ct. It did not do so. The warrant first requested location information from all Google account holders who entered the geofence within an hour. For those Google accounts, the warrant further sought “contextual data points with points of travel outside of the” Geofence for yet another hour—and those data points retained no geographical restriction. (ECF No. 54-1, at 4.) Surprisingly, however, the Government claimed that law enforcement had probable cause for all the information (Steps 1, 2, 3) to be obtained from any user in the geofence. This is despite not having taken any further measures. The warrant did not contain any evidence to prove probable cause for each individual to obtain such intrusive and broad data.

That is not the Fourth Amendment standard I see.

An ordinary rule for searching warrants is to have probable cause of evidence being found in the location searched.  It is not necessary that probable cause must exist. Every individual has their own evidenceBeing evidence is itself.  Consider, for example, that the government wants to search a residence where four persons live.  To obtain a home warrant, investigators do not need to prove that four of those people were involved in the crime.  The government does not need any evidence. AnyEach of the four suspects are implicated in the crime.  The only thing that really matters is the probable suspicion that evidence or contraband may be found within the residence.  It doesn’t matter who the evidence is or how many of the residents live there. That being said, it’s difficult to see how a warrant for geofence can require probable cause that each phone will be disclosed in the geofence.

Judge Lauck misses this because he misunderstands an exception as a rule. Search warrants that search the body of an undercover person are allowed to be executed in accordance with the normal rule. However, there is an exception. Ybarra v. Illinois.  YbarraThe search included a bartender named “Greg” being suspected of selling drug.  The agents obtained warrants to search Greg and search the tavern. They searched the tavern for customers and discovered drugs on Ybarra.  According to the Supreme Court, physically searching customers who are not suspects in the crime was sufficient.

Every patron that entered the Aurora Tap Tavern in March 1976 was provided with constitutional protection from unreasonable searches and unreasonable seizures. That individualized protection was separate and distinct from  the Fourth and Fourteenth Amendment protection possessed by the proprietor of the tavern or by “Greg.” Even though the warrant of probable cause granted the officers permission to search the premises, and “Greg”, it didn’t give them the right to intrude on the constitutional protections enjoyed by each individual customer.

It’s not clear to me how it works. Ybarraa relevant matter to Fourth Amendment geofence warrants.  In the case, the line is drawn between (1) searching for places or things and (2) searching for the body of people.  It seems quite obvious that Google gathering location data is not a search on a person’s body.  The discovery that Google records exist in California showing that a person was within a certain area of a Virginia bank in 2019, is quite clearly different to searching through someone’s pocket and submitting their physical body for a search.

V. Which Standard is for Particularity?

Let’s not forget the final question. If probable cause exists, then how wide could the search go?  The final question is: If there was probable cause, how broad could the search be? ChatrieIt is tedious because of the extensive (in my eyes erroneous!) probable cause analysis.  If it is necessary for the government to establish probable cause each phone in the geofence was involved in the crime then this would make the particularity requirement more clear: the government should issue a warrant to ensure that the phone does not belong to an innocent individual.  Judge Lauck admits that it is not evident that this is possible.

Here’s the main passage of the opinion about particularity.

In fact, the warrant’s scope is impossible to understate, especially considering the government’s narrow probable cause. The perpetrator was only known to have a cellphone in his right arm and that he appeared to be talking with another person on it. (ECF No. 54-1, at 6.) Police failed to find the suspect by reviewing surveillance video, talking with witnesses and following two leads. Law enforcement simply made a circular with a radius of 150 meters. This circle included the Bank and all the Church lots. The government requested the location data for all devices within this area. Carpenter, 138 S. Ct. 216, 2216 (2018). The Government requested location data for every device within the area.

Furthermore, in one incident, Geofence Warrant recorded location data from a user. This could have prevented the Bank’s participation or witnessing the robbery. Geofence Warrants might have reported location data for a user who was within 387 meters of one of their confidence intervals. This is despite the possibility that the user may simply have been in the same area. The person might have dined at Ruby Tuesday near his home. This person could have been at the Hampton Inn Hotel just north of Bank. He or she may have also been at home, in either the Genito Glen apartments complex or the local senior living facility. The person could have been moving furniture to the self-storage facility nearby. In fact, the individual may just have been driving down Hull Street or Price Club Boulevard. However, the Government got the information about the person’s exact location. The Government claims that footage depicting the perpetrator holding a phone to his ear—and nothing else—justified this sweeping warrant. This is not true.[ ]reasonable.” U.S. Const. amend. IV.

It’s not clear that this analysis is particularly useful. Although it’s true that Google Location Information is an actual search, some interesting questions are raised about the uniqueness of a geofence warrant.  It is like searching for that exact physical place.  Does it depend on probable cause?  It is based solely on the movement of the telephone, and not any identifiable information.  Is it determined by the identity of the subscriber?  These are important and interesting questions that I believe judges need to be asking.

Judge Lauck appears to have shifted his attention away from the possibility of the government learning the identity of someone not implicated in the crime. Judge Lauck suggests that it is not “reasonable” for the government, while trying to identify guilty persons, to gain information about innocent individuals.  This is an important concern, as it is policy. Google should consider this in their business roles. It’s not worth the government having irrelevant information if they don’t want it.

It’s unclear how this prospect can make the warrant inconstitutional.  Executing warrants is not the only time that the government finds evidence of innocent individuals.  Remember the home search: A government search might be done to search for evidence in a residence and possibly search bedrooms of those not implicated.  It’s not ideal.  We all would rather live in a world that the government finds only the bad guys, and does not learn about any other people.  This has been the Fourth Amendment’s requirement.

The possibility that technology may allow warrants being executed more securely than conventional warrants has led Judge Lauck, in essence seeking a Fourth Amendment standard that would make warrants as private and secure as possible.  It’s an interesting concept, but this would require a major shift in the law.  It would be easier to achieve this goal through restrictions on use than by ex ante limitations on probable cause.


Judge Lauck concluded that the warrant was in violation of the Fourth Amendment. However, the good faith exception is applicable because these legal questions are new.  We may eventually see the warrant and all of these legal issues on appeal to the Fourth Circuit.  These legal questions are unique, and I think it would be exciting to see the responses from other courts. Stay tuned, as always.