State v. Andrews

LEAHY, J. “[Mjodern cell phones ... are now such a pervasive and insistent part of daily life that the proverbial visitor from Mars might conclude they were an important feature of human anatomy.” Riley v. California, — U.S.-, 134 S.Ct. 2473, 2484 , 189 L.Ed.2d 430 (2014). This case presents a Fourth Amendment issue of first impression in this State: whether a cell phone — a piece of technology so ubiquitous as to be on the person of practically every citizen — may be transformed into a real-time tracking device by the government without a warrant. On the evening of May 5, 2014, the Baltimore City Police Department (BPD) used an active cell site simulator, without a warrant, to locate Appellee Kerron Andrews who was wanted on charges of attempted murder. The cell site simulator, known under the brand name “Hailstorm,” forced Andrews’s cell phone into transmitting signals that allowed the police to track it to a precise location inside a residence located at 5032 Clifton Avenue in Baltimore City.

The officers found Andrews sitting on the couch in the living room and arrested him pursuant to a valid arrest warrant. The cell phone was in his pants pocket. After obtaining a warrant to search the residence, the police found a gun in the cushions of the couch. In the Circuit Court for Baltimore City, Andrews successfully argued that the warrantless use of the Hailstorm device was an unreasonable search under the Fourth Amendment of the United States Constitution.

The court suppressed all evidence obtained by the police from the residence as fruit of the poisonous tree. The State, pursuant to Maryland Code (1973, 2013 RepLVol., 2015 Supp.), Courts and Judicial Pro ³⁵⁵ ceedings Article (“CJP”), § 12 — 302(c)(4), now appeals the court’s decision to suppress that evidence. The specific questions before us, as framed by the State, are: 1) Did the motions court err in finding that the use of a cellular tracking device to locate Andrews’s phone violated the Fourth Amendment? 2) Did the motions court err in finding that Andrews did not have to show standing before challenging the search of the home where he was arrested? 3) Did the motions court err in finding that the search warrant for the home where Andrews was located was invalid? 4) Did the motions court err in excluding the items recovered in this case? We conclude that people have a reasonable expectation that their cell phones will not be used as real-time tracking devices by law enforcement, and — recognizing that the Fourth Amendment protects people and not simply areas — that people have an objectively reasonable expectation of privacy in real-time cell phone location information.

Thus, we hold that the use of a cell site simulator requires a valid search warrant, or an order satisfying the constitutional requisites of a warrant, unless an established exception to the warrant requirement applies. We hold that BPD’s use of Hailstorm was not supported by a warrant or an order requiring a showing of probable cause and reasonable limitations on the scope and manner of the search. Once the constitutionally tainted information, obtained through the use of Hailstorm, was excised from the subsequently issued search warrant for 5032 Clifton Avenue, what remained was insufficient to establish probable cause for a search of that residence. Because the antecedent Fourth Amendment violation by police provided the only information relied upon to establish probable cause in their warrant application, those same officers cannot find shelter in the good faith ³⁵⁶ exception, and the evidence seized in that search withers as fruit of the poisoned tree.

We affirm. BACKGROUND Andrews was positively identified via photographic array as the person who shot three people on April 27, 2014, as they were attempting to purchase drugs on the 4900 block of Stafford Street in Baltimore City. 1 He was charged with attempted first-degree murder and attendant offenses in connection with the shooting, and a warrant for his arrest was issued on May 2, 2014. Pen Register and Trap & Trace Order Unable to locate Andrews, Detective Michael Spinnato of the BPD confirmed Andrews’s cell phone number through a confidential informant, and then submitted an application in the Circuit Court for Baltimore City for a pen register/trap & trace order for Andrews’s cell phone. 2 Specifically, Det. Spinnato requested authorization for the “installation and use of device known as a “Pen Register\Trap & Trace and Cellular Tracking Device to include cell site information, call detail, ³⁵⁷ without geographical limits, which registers telephone numbers dialed or pulsed from or to the telephone(s) having the number(s).... ” The application stated that Andrews was aware of the arrest warrant, and that to hide from police suspects will contact family, girlfriends, and other acquaintances to assist in their day to day covert affairs.

Detective Spinnato would like to track/monitor Mr. Andrews’[s] cell phone activity to further the investigation an [sic] assist in Mr. Andrews’[s] apprehension. Your Applicant hereby certifies that the information likely to be obtained concerning the aforesaid individual’s location will be obtained by learning the numbers, locations and subscribers of the telephone number(s) being dialed or pulsed from or to the aforesaid telephone and that such information is relevant to the ongoing criminal investigation being conducted by the Agency. On May 5, 2014, Det. Spinnato’s application was approved in a signed order stating, in part: [T]he Court finds that probable cause exists and that the applicant has certified that the information likely to be obtained by the use of the above listed device(s) is relevant to an ongoing criminal investigation, To wit: Attempted Murder.

(Emphasis in original). And, as requested in the application, the court, ORDERED, pursuant to Section 10-4B-04 of the Courts and Judicial Proceedings Article ... [Applicants] are authorized to use for a period of sixty (60) days from the date of installation, a Pen Register \ Trap & Trace and Cellular Tracking Device to include cell site information, call detail, without geographical limits ... ORDERED, ... [t]he Agencies are authorized to employ surreptitious or duplication of facilities, technical devices ³⁵⁸ or equipment to accomplish the installation and use of a Pen Register \ Trap & Trace and Cellular Tracking Device, unobtrusively and with a minimum of interference to the service of subscriber(s) of the aforesaid telephone, and shall initiate a signal to determine the location of the subject’s mobile device____ (Emphasis added). Cell Phone in a Hailstorm As soon as Det.

Spinnato obtained the pen register\trap & trace order on May 5, he sent a copy to the BPD’s Advanced Technical Team (the “ATT”). The ATT then issued a form request to the service provider (Sprint) for the following: subscriber information; historical cell site location information (“CSLI”) for the period from April 5 to May 5, 2014; pen register data for 60 days; and precision GPS data from Andrews’s phone. 3 An additional request followed for “GPS Precise Locations and email.” ³⁵⁹ Later on the same day — May 5 — Det. Spinnato began receiving emails from ATT with GPS coordinates for Andrews’s cell phone (within a range of a 200 to 1600 meter radius). Det.

Spinnato and officers from the Warrant Apprehension Task Force (“WATF”) proceeded to the general area and waited until they received information from ATT that the cell phone was in the area of 5000 Clifton Avenue, Baltimore City. They proceeded to an area where there were approximately 30 to 35 apartments around a U-shaped sidewalk. Detective John Haley from ATT arrived and, using a cell site simulator known by the brand name “Hailstorm,” was able to pinpoint the location of the cell phone as being inside the residence at 5032 Clifton Avenue. 4 Det. Spinnato knocked on the door and, after obtaining the consent of the woman who answered, entered the residence along with several other officers.

They found Andrews seated on the couch in the living room with the cell phone in his pants pocket. Det. Spinnato arrested Andrews and secured the location until a search warrant could be obtained. Once they had the warrant, the BPD searched the home and found a gun in the couch cushions.

Initial Hearings Andrews was indicted by a grand jury on May 29, 2014, on numerous charges related to the April 27, 2014 shooting. On July 1, 2014, the Assistant Public Defender representing Andrews filed an “omnibus” motion including requests for discovery and the production of documents. The State responded ³⁶⁰ with an initial disclosure and supplemental disclosure on July 9 and 11, respectively. Those disclosures, however, failed to reveal the method used to locate Andrews on the date of his arrest.

On November 3, 2014, defense counsel filed a supplemental discovery request seeking, inter alia, “[a]ll evidence indicating how Andrews was located at 5032 Clifton Avenue.” The State’s response to that request, dated January 8, 2015, stated, “[a]t this time the State does not possess information related to the method used to locate [Andrews] at 5032 Clifton Avenue.” However, five months later defense counsel received an email from the Assistant State’s Attorney (“ASA”) assigned to the case indicating that it was her understanding that “the ATT used a stingray to locate[ ] your client via his cell phone,” but she was waiting for “the paperwork.” The next day, May 7, the ASA also notified defense counsel of exculpatory evidence in the form of a negative photo array that was conducted the previous January. On May 12, 2015, defense counsel requested that the court dismiss the case based on discovery violations and moved for suppression of evidence, including the gun, phone records, and identification testimony. A few days later, on May 15, the State filed a supplemental disclosure, which provided: WATF did not have the Clifton Ave address as a possible location until ATT provided that information. Det.

Spinnato recalls that he was in touch with Det. Haley from ATT. ATT was provided that information from Sprint in the form of GPS coordinates, Det. Spinnato received the same information either from Sprint directly, or forwarded from ATT.

Det. Spinnato provided ATT with the phone number associated to Defendant from the shooting investigation and, [redacted in original]-Det. Spinnato recalls that ATT gave Det. Spinnato the Clifton Ave address in the afternoon/early evening on May 5, 2014____ The State’s supplemental disclosure also identified a second negative photo array conducted on May 4, 2014. ³⁶¹ Andrews’s initial motions were heard in the circuit court on May 12, 21, and June 4, 2015.

At the conclusion of the hearing on June 4, the circuit court found that one of the lead investigators intentionally withheld exculpatory evidence — including both negative photo arrays. As a result, the circuit court partially granted the pending defense motion for sanctions and excluded that detective’s testimony from trial. The court declined to dismiss the case and denied the motion to exclude the gun and cell phone on the basis of the State’s withholding of discoverable materials. However, as a consequence of the State’s failure to timely disclose information concerning Hailstorm surveillance technology that was used by the BPD, the Court granted the defense additional time to file a motion to suppress.

Motion to Suppress Andrews filed a Motion to Suppress — over 50 pages including exhibits — on June 30, 2015, in which he challenged the BPD’s surreptitious use of the Hailstorm cell site simulator to search Andrews’s phone, without a warrant, under the Fourth Amendment to the United States Constitution. Andrews moved to suppress all evidence obtained from 5032 Clifton Avenue. During the ensuing hearing on the motion to suppress, held August 20, 2015, the State suggested, and the defense agreed, that the circuit court rely on the transcripts and exhibits from the earlier motions hearings for an understanding of the function of the Hailstorm device and its use by the BPD: [STATE’S ATTORNEY]: ... The exact testimony that we’re going to hear about with regard to the Fourth Amendment issue Counsel heard as it related to the discovery issue because the discovery issue bled into the Fourth Amendment issue.

So there is nothing new. There is nothing — Counsel’s aware that the equipment is called Hailstorm not Stingray because of the testimony that Counsel heard and extracted from the detective as it relates to this very case. So there simply is, there is nothing new. We’re at the exact same issue that we were two months ago. ³⁶² THE COURT: So do we even need, do you need to call the witness or can I just rely on the transcript? [STATE’S ATTORNEY]: It would seem to me to rely on the transcript.

THE COURT: ... So the State is indicating that the testimony that the State would present today is the same testimony that was presented— [DEFENSE COUNSEL]: Right. THE COURT: —there. [DEFENSE COUNSEL]: Right. THE COURT: And that’s in the transcript, and the Court can just rely on the transcript to rule on your motion. [DEFENSE COUNSEL]: Right.

THE COURT: You’re fine with that? [DEFENSE COUNSEL]: Yep. The court took a recess for several hours to review the motions and transcripts. The following excerpts from the June 4th hearing, entered as Defendant’s Exhibit 1C, pertain to the function of the cell site simulator: [DETECTIVE HALEY]: What happened in this case was, Detective Sp[innato] from our WATF, which is the Warrant Apprehension Unit, apparently interviewed somebody — got a phone number. He then responds down here to the Circuit Court ... and gets a Court Order signed.

He then sends the Court order down to our office, depending on what the carrier is, Verizon, Sprint, T-Mobile, AT & T. We then send it to them. I ask for subscriber information, call-detail records. They provide us with GPS locations, in this case. And once we get all the information, then we have equipment that we can go out and locate cell phones. [DEFENSE COUNSEL]: Okay.

When you say, we have equipment that we can locate cell phones, you’re talking about the Stingray equipment, is that what was used in this case? ³⁶³ [DETECTIVE HALEY]: Yeah, it’s called the Hailstorm. It used to be — Stingray is kind of first generation. * * * [DEFENSE COUNSEL]: Tell me what the Hailstorm does. [DETECTIVE HALEY]: What we get from the phone company is the subscriber information. So, when we get the subscriber information, it has a [sic] identifier on there, if you will, a serial number. We put that into the Hailstorm equipment.

And the Hailstorm equipment acts like a cell tower. So, we go into a certain area, and basically, the equipment is looking for that particular identifier, that serial number. [DEFENSE COUNSEL]: Okay. And so, if a person is inside of a home, that equipment peers over the wall of the home, to see if that cell phone is behind the wall of that house, right? [DETECTIVE HALEY]: Yes. [DEFENSE COUNSEL]: And it sends an electronic transmission through the wall of that house, correct? [DETECTIVE HALEY]: Yes. [DEFENSE COUNSEL]: Did you get a separate search warrant for that search into the home? [DETECTIVE HALEY]: You’d have to talk to Detective Spinnato about that. Because he’s the one that got the Court Order signed. [DEFENSE COUNSEL]: Did you do the search?

You conducted the equipment in this — you operated— [DETECTIVE HALEY]: Yes. [DEFENSE COUNSEL]: —the equipment? [DETECTIVE HALEY]: Yes. [DEFENSE COUNSEL]: Tell me all of the information the Hailstorm can retrieve from a phone. ³⁶⁴ [DETECTIVE HALEY]: It’s going to retrieve, like I said before, the serial number of the phone, depending on what kind of phone it is. It’s going to — there’s [sic] different identifiers. Like for Sprint, in this case, it’s called the MSID. And that’s like a ten-digit — like a ten-digit number.

So, it’s retrieving that. And there’s also the electronic serial number. It’s retrieving that. And that’s really it. [DEFENSE COUNSEL]: Can you capture the telephone calls as they’re being made? [DETECTIVE HALEY]: No. [DEFENSE COUNSEL]: And how do you know where the phone — and it doesn’t capture any data on the phone? [DETECTIVE HALEY]: No. [DEFENSE COUNSEL]: Are you sure? [DETECTIVE HALEY]: Yes. [DEFENSE COUNSEL]: So, how do you get information about where the phone is on the machine? [DETECTIVE HALEY]: Because when it captures that identifier that you put into the machine or the equipment, it then tells you — it looks like a clock on the equipment.

And it tells you where the signal’s coming from, like 12, 1, 2, 3 o’clock (indicating). And it will give you like a reading. Like if it says 1:00 at like an 80, well, then you know that you’re kind of close to it. But if it says 1:00 at like a 40, then you know that you’re probably within, I don’t know, probably, you know, 20 yards of it. [DEFENSE COUNSEL]: The person doesn’t have to be using their phone for you to get that information, do they? [DETECTIVE HALEY]: Actually, if they’re on their phone, then they’re already connected to — in this case, the Sprint network.

And we’re not going to be able to pull them off of that until they’re — until they hang — until they hang the call up. [DEFENSE COUNSEL]: So, they hang the call up. And the phone can be in their pocket, right? [DETECTIVE HALEY]: Correct. ³⁶⁵ [DEFENSE COUNSEL]: And then you’re reaching in to grab an electronic signal about where that phone is? It’s not pinging, in other words, right? MR.

HALEY: Like I said, our equipment acts like a cell tower. So, it draws the phone to our equipment. [DEFENSE COUNSEL]: But you just said, if the person’s on the phone, your equipment won’t work, right? [DETECTIVE HALEY]: Correct. [DEFENSE COUNSEL]: So, it doesn’t act like a cell tower, because you can find the phone only when they are not on the phone, correct? [DETECTIVE HALEY]: Well, I would say it does act like a cell tower, because the only time that you’re going to connect — the only time that you’re going to connect to the network, or to a tower is when you go to try to use it. [DEFENSE COUNSEL]: But you’re connecting to where the phone is, when they’re not on the phone, didn’t you just say that [DETECTIVE HALEY]: Maybe I’m getting confused, or I’m not understanding what you’re asking me. [DEFENSE COUNSEL]: My question to you was, for example, I have my phone in my pocket. And I’m sitting in my house, right? [DETECTIVE HALEY]: Okay. [DEFENSE COUNSEL]: And you want to know where I am, correct? [DETECTIVE HALEY]: Okay. [DEFENSE COUNSEL]: When I am not on my phone, you will drive by my house, and you will get a signal from my phone indicating where I am, right? [DETECTIVE HALEY]: Correct. [DEFENSE COUNSEL]: If I am using the phone, you won’t get that signal, right? ³⁶⁶ [DETECTIVE HALEY]: Correct. [DEFENSE COUNSEL]: So, the phone cannot be in use. You are searching for my phone as you’re driving through my neighborhood, right? [DETECTIVE HALEY]: Yes. [DEFENSE COUNSEL]: And in order to get to my phone, you are sending an electronic signal into my house, right? [DETECTIVE HALEY]: Yes.

When the hearing resumed, the court made several preliminary findings, and invited counsel to respond. In regard to the pen register/trap & trace order, the court observed: I don’t find that Judge Williams’ order is invalid as a pen register or trap and trace, but I do find that the order does not authorize the use of Hailstorm and I ... invite the State to tell me otherwise. So this is very different from an order authorizing, for example, GPS or cell site information, because that is information that’s generated by the phone. And my understanding of this equipment is essentially that it’s forcing the .phone to emit information, or its taking information from the phone that the phone is not sort of on its own generating at the time which is very different.

On the issue of whether Andrews’s arrest was lawful, the parties acknowledged that a valid warrant was outstanding for his arrest. However, the court questioned whether, as argued by defense counsel, Andrews’s presence at 5032 Clifton Avenue “or the warrant they got as a result of him being there is fruit of the poisonous tree because there was a violation of his Fourth Amendment rights by [Det. Haley] using the Hailstorm on this phone to locate him at that residence in the first place.” Looking then to the application for the warrant to search 5032 Clifton Avenue, the court noted that there was no independent corroboration for the warrant because, “all it says he was located at this address and so we want to search this address. I mean that’s really all it says.” ³⁶⁷ After hearing argument, the circuit court found that “the use of the Hailstorm violates the Defendant’s Fourth Amendment rights,” and “any information generated from the use of the Hailstorm [must] be suppressed.” The court continued on the record: And so just so that I’m clear, it means that the jury cannot hear any testimony or evidence about information obtained from the Hailstorm, obtained through the Hailstorm device.

And just so that I’m clear, it’s my understanding that the Hailstorm device is what told the police that the Defendant was at that location. And so that includes any testimony or evidence then that the Defendant was at that location, if that’s what — because that’s what the Hailstorm told the police. And so the jury would be prohibited from hearing evidence or testimony of that. It does not invalidate the arrest or the search [incident to] the arrest with the phone that’s in his pocket.[ 5 ] Now anything that came off the phone, again if it came through the Hailstorm device it is suppressed.

There can be no evidence or testimony about it. And then again, any police knowledge that the Defendant was at that location again also suppressed, so the jury would not be able to hear any evidence or testimony of that. So then that leaves us with the fruit of the poisonous tree argument for the search and seizure warrant. I reviewed the warrant and it literally says the Defendant was in there so now we need a warrant.

And information generated from the use of the Hailstorm be suppressed, that’s all that it is. And so I analyze this different, a little bit different from a normal sort of motion to suppress a search and seizure warrant or even Franks in terms of standing. ³⁶⁸ I don’t — I understand the State’s argument in terms of standing and this not being his residence, and the Defense’s argument that he was at a minimum an overnight guest and has some reasonable expectation of privacy. I don’t think I need to reach those issues because the warrant is really just fruit of the poisonous tree of the illegally obtained information about the Defendant’s location. That’s what it is.

And so I am granting the suppression of that for that very reason. And so that the record is clear — and I know that the State is asking to take an appeal, the record is clear. The ruling of the Court is that the government violated the Defendant’s Fourth Amendment rights by essentially using the Hailstorm to locate him at that residence. The State noticed its appeal on September 3, 2015.

DISCUSSION Motion to Dismiss Before turning to the merits, we must address Andrews’s motion to dismiss this appeal on the ground that the notice of appeal was defective, and therefore, not filed within the time prescribed by Rule 8-202. The State filed its notice of appeal on September 3, 2015; however, the signed certificate of service — indicating that a copy of the notice was “mailed first — class, postage prepaid” on that same day — failed to list the party that was served. Andrews acknowledges that a copy of the notice was delivered to the Office of the Public Defender on September 4, 2015. Nevertheless, Andrews argues that the State’s notice did not comply with the certificate of service requirements of Maryland Rule 1-323, and that the clerk should not have accepted the filing.

Consequently, according to Andrews, no valid notice of appeal was filed in this case. The State concedes that the failure to name the party to be served was a defect in the certificate of service, but maintains the clerk was required to accept the filing because the certificate complied with the literal requirements of Rule 1-323. The State urges that it ³⁶⁹ would be improper to dismiss the appeal because there is no dispute that the opposing party was served in a timely fashion. Maryland Rule 1-323 directs that the court clerk may not accept for filing a pleading or other paper requiring service, unless it is accompanied by “an admission or waiver of service or a signed certificate showing the date and manner of making service.” In Director of Finance of Baltimore City v. Harris, this Court addressed whether a certificate of service that failed to identify all the persons upon whom service was required should have been rejected for filing by the court clerk. 90 Md.App. 506, 513-14 , 602 A.2d 191 (1992).

Looking to the 1984 revision of the Maryland Rules that produced the current Rule 1-323, this Court observed: Under the old Rule, the clerk may have had some obligation to determine whether the certificate actually showed service on the “opposite party.” But, as noted, that obligation, if ever did exist, has been eliminated____The obligation of the clerk under the current Rule is simply to assure that there is, in fact, an admission, a waiver, or a certificate showing the date and manner of service. If such a certificate attached to the paper, the clerk must file the paper, leaving it then to the parties or the court to deal with any deficiency.[ 6 ] ³⁷⁰ More recently, in Lovero v. Da Silva, this Court clarified that, by mandating that proof of service (or a waiver of service) appear on each pleading or paper, “Rule 1-323 assures the court ... that each party has been duly notified before action is taken by the court in response to or as a result of the subject pleading or paper.” 200 Md.App. 433, 446 , 28 A.3d 43 (2011). We determined that Lovero’s notice of appeal should have been rejected by the clerk, explaining that [wjhere, as in the instant case, the notice of appeal contains no proof of service whatsoever, we have no basis upon which to conclude that the notice of appeal was served on the opposing party or parties. Indeed, it is undisputed here that the Notice of Appeal was never served on Da Silva.

Id. at 449 , 28 A.3d 43 . In the present case, there is no dispute that the notice was served on defense counsel. Indeed, the State made it clear at the August 20 hearing that it would be filing an appeal as reflected in the court’s ruling; “and so that the record is clear — and I know that the State is asking to take an appeal, the record is clear.” It is also clear now that, although the omission in the certificate of service is a defect, the certificate met the literal requirements of Rule 1-323 — it provided the date and manner of service. Where there is no evidence that Andrews was prejudiced or that the course of the appeal was delayed by a defect, “it is the practice of this Court to decide appeals on the merits rather than on technicalities.” Bond v. Slavin, 157 Md.App. 340, 352-53 , 851 A.2d 598 (2004).

Cf. Williams v. Hofmann Balancing Techniques, Ltd., 139 Md. App. 339, 356-57 , 776 A.2d 4 (2001) (holding that the appellant’s failure to identify one of the appellees on his notice of appeal did not deprive this Court of jurisdiction). To be sure, the Court of Appeals has observed that “[o]ur cases, and those of the Court of Special Appeals, have generally been quite liberal in construing timely orders for appeal.” Newman v. Reilly, 314 Md. 364, 386 , 550 A.2d 959 (1988); see also Lovero, 200 Md.App. at 450 -51 n. 8, 28 A.3d 43 (and the cases cited therein) (recognizing that where a challenged notice of appeal was timely filed the courts of Maryland construe the notice in ³⁷¹ favor of deciding the appeal on the merits). We deny Andrews’s motion to dismiss the appeal.

Standard of Review We review the grant of a motion to suppress based on the record of the suppression hearing, and we view the facts in the light most favorable to the prevailing party. State v. Donaldson, 221 Md.App. 134, 138 , 108 A.3d 500 (citing Holt v. State, 435 Md. 443, 457 , 78 A.3d 415 (2013)), cert. denied, 442 Md. 745 , 114 A.3d 711 (2015). Further, “we extend ‘great deference’ to the factual findings and credibility determinations of the circuit court, and review those findings only for clear error.” Id. (citing Brown v. State, 397 Md. 89, 98 , 916 A.2d 245 (2007)).

But we make an independent, de novo, appraisal of whether a constitutional right has been violated by applying the law to facts presented in a particular case. Williams v. State, 372 Md. 386, 401 , 813 A.2d 231 (2002) (citations omitted); see also Brown, 397 Md. at 98 , 916 A.2d 245 (“[W]e review the court’s legal conclusions de novo and exercise our independent judgment as to whether an officer’s encounter with a criminal defendant was lawful.” (Citation omitted)). I. Fourth Amendment Search In 1966, in the wake of prominent Congressional hearings on government invasions of privacy, Justice Douglas, dissenting in Osborn v. United States and Lewis v. United States, and concurring in Hoffa v. United States, observed: We are rapidly entering the age of no privacy, where everyone is open to surveillance at all times; where there are no secrets from government. The aggressive breaches of privacy by the Government increase by geometric proportions.

Wiretapping and ‘bugging’ run rampant, without effective judicial or legislative control. Taken individually, each step may be of little consequence. But when viewed as a whole, there begins to emerge a ³⁷² society quite unlike any we have seen — a society in which government may intrude into the secret regions of man’s life at will. Osborn v. United States, 385 U.S. 323, 340-43 , 87 S.Ct. 429 , 17 L.Ed.2d 394 (1966) (Douglas, J., dissenting). 7 Fifty years later we face the same concern — to what extent have advances in technology created an “age of no privacy.” 8 The Fourth Amendment to the United States Constitution, made applicable to the States by the Fourteenth Amendment, Mapp v. Ohio, 367 U.S. 643, 655 , 81 S.Ct. 1684 , 6 L.Ed.2d 1081 (1961), provides: 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 probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

U.S. Const, amend.

IV

The first clause protects individuals against unreasonable searches and seizures, 9 see Katz v. Unit ³⁷³ ed States, 389 U.S. 347, 359 , 88 S.Ct. 507 , 19 L.Ed.2d 576 (1967) (“Wherever a man may be, he is entitled to know that he will remain free from unreasonable searches and seizures[ ]”), and the second clause requires that warrants must be particular and supported by probable cause, see Payton v. New York, 445 U.S. 573, 584 , 100 S.Ct. 1371 , 63 L.Ed.2d 639 (1980). A “search” within the meaning of the Fourth Amendment occurs where the government invades a matter in which a person has an expectation of privacy that society is willing to recognize as reasonable. Kyllo v. United States, 533 U.S. 27, 33 , 121 S.Ct. 2038 , 150 L.Ed.2d 94 (2001) (citing Katz, 389 U.S. at 361 , 88 S.Ct. 507 (Harlan, J., concurring)). As we made clear in Raynor v. State, “[t]he burden of demonstrating a ‘legitimate’ or ‘reasonable’ expectation of privacy includes both a subjective and an objective component.” 201 Md.App. 209, 218 , 29 A.3d 617 (2011), aff'd, 440 Md. 71 , 99 A.3d 753 (2014) (citation and footnote omitted). “[I]n order to claim the protection of the Fourth Amendment, a defendant must demonstrate that he personally has an expectation of privacy in the place searched, and that his expectation is reasonable; i.e., one that has ‘a source outside of the Fourth Amendment, either by reference to concepts of real or personal property law or to understandings that are recognized and permitted by society.’” Minnesota v. Carter, 525 U.S. 83, 88 , 119 S.Ct. 469 , 142 L.Ed.2d 373 (1998) (quoting Rakas v. Illinois, 439 U.S. 128 , 143-44 n. 12, 99 S.Ct. 421 , 58 L.Ed.2d 387 (1978)).

The Fourth Amendment protects not against all intrusions as such, “but against intrusions which are not justified in the circumstances, or which are made in an improper manner.” Maryland v. King, — U.S.-, 133 S.Ct. 1958, 1969 , 186 L.Ed.2d 1 (2013) (emphasis added) (quoting Schmerber v. California, 384 U.S. 757, 768 , 86 S.Ct. 1826 , 16 L.Ed.2d 908 (1966)). “Although the underlying com ³⁷⁴ mand of the Fourth Amendment is always that searches and seizures be reasonable, what is reasonable depends on the context within which a search takes place.” State v. Alexander, 124 Md.App. 258, 265 , 721 A.2d 275 (1998) (emphasis added in Alexander) (quoting New Jersey v. T.L.O., 469 U.S. 825 , 337, 105 S.Ct. 733 , 83 L.Ed.2d 720 (1985)). Subject to a few well-delineated exceptions, “warrantless searches ‘are per se unreasonable under the Fourth Amendment.’ ” Quon, 560 U.S. at 760, 130 S.Ct. 2619 (2010) (quoting Katz, 389 U.S. at 357 , 88 S.Ct. 507 ); see also United States v. Karo, 468 U.S. 705, 717 , 104 S.Ct. 3296 , 82 L.Ed.2d 530 (1984) (citations omitted). a. Effects of the Nondisclosure Agreement Before we examine the reasonableness of the State’s intrusion in context, we address the nondisclosure agreement entered into between the State’s Attorney for Baltimore City and the Federal Bureau of Investigation in early August 2011 as a condition of BPD’s purchase of certain “wireless collection equipment/technology manufactured by Harris [Corporation].” The nondisclosure agreement provided, in part: [T]o ensure that [ ] wireless collection equipment/technology continues to be available for use by the law enforcement community, the equipment/technology and any information related to its functions, operation, and use shall be protected from potential compromise by precluding disclosure of this information to the public in any manner including b[ut] not limited to: in press release, in court documents, during judicial hearings, or during other public forums or proceedings. Accordingly, the Baltimore City Police Department agrees to the following conditions in connection with its purchase and use of the Harris Corporation equipment/technology: 5.

The Baltimore City Police Department and Office of the State’s Attorney for Baltimore City shall not, in any civil or criminal proceeding, use or provide any information ³⁷⁵ concerning the Harris Corporation wireless collection equipment/technology, its associated software, operating manuals, and any related documentation (including its technical/engineering description(s) and capabilities) beyond the evidentiary results obtained through the use the equipment/technology including, but not limited to, during pre-trial matters, in search warrants and related affidavits, in discovery, in response to court ordered disclosure, in other affidavits, in grand jury hearings, in the State’s case-in-chief, rebuttal, or on appeal, or in testimony in any phase of civil or criminal trial, without the prior written approval of the FBI.... (Emphasis added). The agreement directs that in the event of a Freedom of Information Act request, or a court order directing disclosure of information regarding Harris Corporation equipment or technology, the FBI must be notified immediately to allow them time to intervene “and potentially] compromise.” If necessary “the Office of the State’s Attorney for Baltimore will, at the request of the FBI, seek dismissal of the case in lieu of using or providing, or allowing others to provide, any information concerning the Harris Corporation wireless collection equipment/technology[.]” We observe that such an extensive prohibition on disclosure of information to the court — from special order and/or warrant application through appellate review — prevents the court from exercising its fundamental duties under the Constitution. To undertake the Fourth Amendment analysis and ascertain “the reasonableness in all the circumstances of the particular governmental invasion of a citizen’s personal security,” Terry v. Ohio, 392 U.S. 1, 19 , 88 S.Ct. 1868 , 20 L.Ed.2d 889 (1968), it is self-evident that the court must understand why and how the search is to be conducted.

The reasonableness of a search or seizure depends “ ‘on a balance between the public interest and the individual’s right to personal security free from arbitrary interference by law officers.’” Pennsylvania v. Mimms, 434 U.S. 106, 109 , 98 S.Ct. 330 , 54 L.Ed.2d 331 (1977) (emphasis added) (quoting United States v. Brignoni-Ponce, 422 U.S. 873, 878 , 95 S.Ct. 2574 , 45 ³⁷⁶ L.Ed.2d 607 (1975)). The analytical framework requires analysis of the functionality of the surveillance device and the range of information potentially revealed by its use. A nondisclosure agreement that prevents law enforcement from providing details sufficient to assure the court that a novel method of conducting a search is a reasonable intrusion made in a proper manner and “justified by the circumstances,” obstructs the court’s ability to make the necessary constitutional appraisal. Cf.

King, 133 S.Ct. at 1970 (“Even if a warrant is not required, a search is not beyond Fourth Amendment scrutiny; for it must be reasonable in its scope and manner of execution. Urgent government interests are not a license for indiscriminate police behavior.”). In West v. State, this Court stated that “to assure that the purpose of the Fourth Amendment is upheld, police officers must provide details within affidavits when attempting to acquire search warrants, even if such information would seem to the police officer of trivial consequence at the time.” 137 Md.App. 314, 331 , 768 A.2d 150 (2001). As discussed further in Section III infra, it appears that as a consequence of the nondisclosure agreement, rather than apply for a warrant, prosecutors and police obtained an order under the Maryland pen register statute that failed to provide the necessary information upon which the court could make the constitutional assessments mandated in this case.

The BPD certified to the court that pursuant to the order “the information likely to be obtained concerning the aforesaid individual’s location will be obtained by learning the numbers, locations and subscribers of the telephone number(s) being dialed or pulsed from or to the aforesaid telephone----” However, the suppression court, having the benefit of Det. Haley’s testimony (reproduced above), learned that the BPD actually employed the Hailstorm device, which is capable of obtaining active real-time location information — far different from a pen register (a device or process that records and decodes dialing, routing, addressing, or signaling information transmitted by an instrument) or track and trace device (a device or process that captures the incoming electronic or ³⁷⁷ other impulses that identify the originating number). See fn.2 swpra. 10 We perceive the State’s actions in this case to protect the Hailstorm technology, driven by a nondisclosure agreement to which it bound itself, as detrimental to its position and inimical to the constitutional principles we revere. b. What Constitutes a “Search” — Level of Intrusion and Expectation of Privacy The State argues that the use of a cell site simulator does not constitute a “search” under the Fourth Amendment.

The State maintains that the circuit court’s decision “was based upon both factually unreasonable conclusions about how the cell site simulator worked in this case, and legally incorrect determinations about what constitutes a ‘search.’ ” The State acknowledges that the factual bases for the circuit court’s rulings are found in the June 4, 2015 testimony of Det. Haley. However, the State argues that Det. Haley’s testimony “was necessarily rather summary,” and does not support the factual conclusions of the circuit court.

According to the State, the cell site simulator “acts like a cell tower, and waits to receive a signal bearing the target IMSI” [International Mobil Subscriber Identity]. The State maintains that, properly construed, Det. Haley’s testimony reveals that “the process of a cell phone sending its identifying information to a cell tower was indistinguishable from the process of a cell phone sending its identifying information to a cell site simulator.” The State asserts that the Hailstorm device “merely reads the ID number regularly transmitted by activated cell phones as part of their ordinary use” and “[w]hen the device detects a signal from the target phone, it notifies the operator the direction of the signal and the relative strength, allowing the operator to estimate the probable location of the phone.” Therefore, the State argues that ³⁷⁸ no reasonable expectation of privacy existed in the information obtained by the Hailstorm device and no intrusion or “search” occurred. Andrews countercharges that there was ample, explicit support in the record for the circuit court’s finding that the Hailstorm device operated by emitting a signal “through the wall of a house” and “into the phone” triggering the phone to respond to the device.

Andrews argues that, through the use of an “active cellular surveillance device,” the State violated his reasonable expectation of privacy in the personal information contained and generated by his cell phone, without which the government would not have been able to discover his location inside the home. Presumably because of the nondisclosure agreement discussed above, the State provided limited information regarding the function and use of the Hailstorm device. And presumably, the State would have limited itself in this manner regardless of whether it relied on testimony from the prior hearing or produced live testimony before the suppression court. 11 Notwithstanding this, it is clear from Det. Haley’s testimony that “the Hailstorm equipment acts like a cell tower,” but, unlike a cell tower awaiting incoming signals, the Hailstorm is an active device that can send an electronic signal through the wall of a house and “draw[ ] the phone to [the] equipment.” Based on the direction and strength of the signal the Hailstorm receives from a cell phone in response, law enforcement can pinpoint the real-time location of a cell phone (and likely the person to whom it belongs) within less than 20 yards.

These points from Det. Haley’s testimony regarding the function of the Hailstorm device are consistent with what ³⁷⁹ other courts and legal scholars have been able to discern about the device. Hailstorm, along with the earlier-model cell site simulator known as “StingRay,” to which Det. Haley referred, are far from discrete, limited surveillance tools.

Rather, as described in a recent article in the Harvard Journal of Law and Technology cited by Appellee and the amici: 12 This technology, commonly called the StingRay, the most well-known brand name of a family of surveillance devices known more generically as “IMSI catchers,” is used by law enforcement agencies to obtain, directly and in real time, unique device identifiers and detailed location information of cellular phones — data that it would otherwise be unable to obtain without the assistance of a wireless carrier. By impersonating a cellular network base station, a StingRay — a surveillance device that can be carried by hand, installed in a vehicle, or even mounted on a drone — tricks all nearby phones and other mobile devices into identifying themselves (by revealing their unique serial numbers) just as they would register with genuine base stations in the immediate vicinity. As each phone in the area identifies itself, the StingRay can determine the location from which the signal came. Stephanie K. Pell & Christopher Soghoian, A Lot More Than A Pen Register, and Less Than A Wiretap: What the Stingray Teaches Us About How Congress Should Approach the Reform of Law Enforcement Surveillance Authorities, 16 Yale J.L. & Tech. 134 , 142, 145-46 (2014) (emphasis added; footnotes omitted).

The Supreme Court of Wisconsin examined whether law enforcement could obtain location data through cell site information or a StingRay pursuant to a warrant and, before ³⁸⁰ holding that the warrant was sufficiently particularized, based on probable cause, and passed constitutional muster, observed: A stingray is an electronic device that mimics the signal from a cellphone tower, which causes the cell phone to send a responding signal. If the stingray is within the cell phone’s signal range, the stingray measures signals from the phone, and based on the cell phone’s signal strength, the stingray can provide an initial general location of the phone. By collecting the cell phone’s signals from several locations, the stingray can develop the location of the phone quite precisely. State v. Tate, 357 Wis.2d 172 , 849 N.W.2d 798 , 826 n. 8 (2014) (citation omitted), cert. denied, — U.S.-, 135 S.Ct. 1166 , 190 L.Ed.2d 921 (2015); see also, e.g., In re Application for Pen Register and Trap/Trace Device with Cell Site Location Authority, 396 F.Supp.2d 747, 755 (S.D.Tex.2005) (defining an earlier-model device, the “Triggerfish,” as equipment that “enables law enforcement to gather cell site location information directly, without the assistance of the service provider”).

We cannot say that the factual findings of the circuit court, in this case, were erroneous; they are firmly grounded in the testimony before that court, and the State has provided no evidence to the contrary. In determining then whether a Fourth Amendment “search” occurred, we apply the court’s factual findings to the test pronounced in Katz, supra. Rather than limit the constitutional appraisal to a trespass analysis, 13 the Katz test requires a two-fold showing: “first that a person have exhibited an actual (subjective) expectation of privacy and, second, that the expectation be one that society is prepared to recognize as ³⁸¹ ‘reasonable.’” 389 U.S. at 361 , 88 S.Ct. 507 (Harlan, J., concurring). 14 Even under the more flexible Katz test, however, rapid advancements in technology make ascertaining what constitutes a search under the Fourth Amendment ever more challenging. 15 ³⁸² Charles Katz was charged with transmitting wagering information by telephone in violation of federal law. Katz, 389 U.S. at 348 , 88 S.Ct. 507 .

He objected during his trial to the government’s introduction of evidence collected by FBI agents who overheard and recorded his end of telephone conversations from inside a public telephone booth. Id. The agents had placed a recording device on the outside of the phone booth from which Katz placed his calls. Id.

The government contended on appeal that their surveillance did not constitute a search prohibited by the Fourth Amendment because Katz was in a public location that was not constitutionally protected and because the technique they employed involved no physical penetration of the telephone booth. Id. at 352 , 88 S.Ct. 507 . Writing for the majority, Justice Stewart rejected the formulation of the issues by the parties, premised on whether the telephone booth was a “constitutionally protected area,” and instructed that “[t]he Fourth Amendment protects people, not places ... what [Katz] seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.” Id. at 361 , 88 S.Ct. 507 (citations omitted). The Court continued, stating that “once it is recognized that the Fourth Amendment protects people — and not simply ‘areas’ — against unreasonable searches and seizures it becomes clear that the reach of that Amendment cannot turn upon the presence or absence of a physical intrusion into any given enclosure.” Id. at 350, 353 , 88 S.Ct. 507 .

Almost 20 years after establishing in Katz that an examination of intrusiveness under the Fourth Amendment is not simply measured by physical invasion, the Supreme Court addressed the constitutionality of the government’s surreptitious use of a radio transmitter to track the movements of a container to and inside a private residence. United States v. Karo, supra, 468 U.S. at 709-10 , 104 S.Ct. 3296 . The physical installation of the transmitter was not at issue; rather, the ³⁸³ question before the Court was “whether the monitoring of a beeper in a private residence, not open to visual surveillance, violates the Fourth Amendment rights of those who have a justifiable interest in the privacy of the residence.” Id. at 714 , 104 S.Ct. 3296 . Although the Court noted that the monitoring of an electronic device is “less intrusive than a full-scale search,” it, nevertheless, reveals information about the interior of the residence that the government “could not have otherwise obtained without a warrant.” Id. at 715 , 104 S.Ct. 3296 .

The Supreme Court stated: We cannot accept the Government’s contention that it should be completely free from the constraints of the Fourth Amendment to determine by means of an electronic device, without warrant and without probable cause or reasonable suspicion, whether a particular article — or a person, for that matter — is in an individual’s home at a particular time. Indiscriminate monitoring of property that has been withdrawn from public view would present far too serious a threat to privacy interests in the home to escape entirely some sort of Fourth Amendment oversight. Id. at 716 , 104 S.Ct. 3296 (footnote omitted). Notably, the Court also soundly rejected the government’s contention that it should be able to engage in warrantless monitoring of an electronic device inside a private residence “if there is the requisite justification in the facts for believing that a crime is being or will be committed and that monitoring the beeper wherever it goes is likely to produce evidence of criminal activity.” Id. at 717 , 104 S.Ct. 3296 (emphasis added).

The Court recognized limited exceptions to the general rule, such as in the case of exigency, but explained why in its view the government exaggerated the difficulties associated with obtaining a warrant: The Government argues that the traditional justifications for the warrant requirement are inapplicable in beeper cases, but to a large extent that argument is based upon the contention, rejected above, that the beeper constitutes only a minuscule intrusion on protected privacy interests. The primary reason for the warrant requirement is to interpose ³⁸⁴ a ‘neutral and detached magistrate’ between the citizen and ‘officer engaged in the often competitive enterprise of ferreting out crime.’ The Government contends that it would be impossible to describe the ‘place’ to be searched, because the location of the place is precisely what is sought to be discovered through the search. [ ] However true that may be, it will still be possible to describe the object into which the beeper is to be placed, the circumstances that led agents to wish to install the beeper, and the length of time for which beeper surveillance is requested. Id. at 717-18 , 104 S.Ct. 3296 (citing Johnson v. United, States, 333 U.S. 10, 14 , 68 S.Ct. 367 , 92 L.Ed. 436 (1948)). In Kyllo, supra, the Supreme Court considered whether a Fourth Amendment search had occurred when the government used a thermal imaging device to detect infrared radiation inside a home. 533 U.S. at 29-30 , 121 S.Ct. 2038 .

Federal agents, suspecting that Danny Kyllo was growing marijuana inside his home, were able to confirm areas of heat coming from high intensity lamps used to grow marijuana plants indoors. Id. At the threshold of his analysis, Justice Scalia, writing for the majority, observed: It would be foolish to contend that the degree of privacy secured to citizens by the Fourth Amendment has been entirely unaffected by the advance of technology.... The question we confront today is what limits there are upon this power of technology to shrink the realm of guaranteed privacy.

Id. at 33-34 , 121 S.Ct. 2038 . The Court then noted that, although the Katz test — “whether the individual has an expectation of privacy that society is prepared to recognize as reasonable” — may be difficult to apply to some locations, such as telephone booths and automobiles — the expectation of privacy in the home had “roots deep in the common law.” Id. at 34, 121 S.Ct. 2038 . ³⁸⁵ In support of the use of its thermal imaging technology, the government in Kyllo argued that there was no “search” because the device detected “ ‘only heat radiating from the external surface of the house[.]’ ” Id. at 35 , 121 S.Ct. 2038 . The Supreme Court, however, cast aside this contention as the kind of mechanical interpretation rejected in Katz and stated, “so also a powerful directional microphone picks up only sound emanating from a house — and a satellite capable of scanning from many miles away would pick up only visible light emanating from a house.” Id. Rather than abandon Katz and take such a mechanical approach, the Court sought to adopt a rule “tak[ing] account of more sophisticated [surveillance] systems that are already in use or in development.” Id. at 35-36, 121 S.Ct. 2038 (footnote omitted).

Accordingly, the Court held that “[w]here ... the Government uses a device that is not in general public use, to explore the details of the home that would previously have been unknowable without physical intrusion, the surveillance is a ‘search’ and is presumptively unreasonable without a warrant.” Id. at 40 , 121 S.Ct. 2038 . Furthermore, the Court repeated the caveat of Silverman v. United States, that the “protection of the home has never been tied to the measurement of the quality or quantity of information obtained” for any invasion of the home, “ ‘by even a fraction of an inch’ [is] too much.” Id. at 37 , 121 S.Ct. 2038 (quoting Silverman v. U.S., 365 U.S. 505, 512 , 81 S.Ct. 679 , 5 L.Ed.2d 734 (1961)). From Katz to Kyllo , the Supreme Court has firmly held that use of surveillance technology not in general public use to obtain information about the interior of a home, not otherwise available without trespass, is a “search” under the Fourth Amendment. These decisions resolved to protect an “expectation of privacy that society is prepared to recognize as reasonable.” After Kyllo , however, the question remained whether electronic tracking or surveillance outside the home could constitute a search under the Fourth Amendment.

In United States v. Jones, the Supreme Court reviewed the use of a GPS tracking device affixed to the undercarriage of a vehicle to track the movements of the defendant over a period ³⁸⁶ of 28 days. — U.S.-, 132 S.Ct. 945 , 948, 181 L.Ed.2d 911 (2012). The Court unanimously affirmed the United States Court of Appeals for the District of Columbia Circuit’s holding that the electronic location surveillance over a period of 28 days was a search and that admission of evidence obtained by the warrantless use of the GPS device violated the Fourth Amendment. The Court was unable, however, to reach full agreement as to the basis for its decision. See id. at 953 (majority opinion); 954 (Sotomayor, J., concurring); 967 (Alito, J., concurring in the judgment).

Justice Scalia’s majority opinion found that a search occurred under the traditional, pre-Katz “trespass” rationale, but acknowledged that “[situations involving merely the transmission of electronic signals without trespass would remain subject to Katz analysis.” Id. at 953 (emphasis in original). Agreeing with Justice Brennan’s concurrence in Knotts v. United States, Justice Scalia expounded that “ ‘when the Government does engage in physical intrusion of a constitutionally protected area in order to obtain information, that intrusion may constitute a violation of the Fourth Amendment.’ ” Id. at 951 (quoting Knotts, 460 U.S. 276, 286 , 103 S.Ct. 1081 , 75 L.Ed.2d 55 (1983)). When law enforcement placed the GPS tracking system on Jones’s vehicle, without a warrant, the government physically invaded a constitutionally protected area, id. at 949, 952, and factors beyond trespass need not be considered to find there was a Fourth Amendment violation. Id. at 953-54.

Justice Scalia explained that the common-law trespass test was essentially a minimum test and that the Katz test was “added to, not substituted for, the common-law trespassory test.” Id. at 952. Justice Sotomayor revisited the Katz analysis in her concurring opinion, stating that, “even in the absence of a trespass, ‘a Fourth Amendment search occurs when the government violates a subjective expectation of privacy that society recognizes as reasonable.’ ” Id. at 954-55 (Sotomayor, J., concurring) (citations omitted). Recognizing that “[i]n cases of electronic or other novel modes of surveillance that do not depend upon a physical invasion on property, the majority ³⁸⁷ opinion’s trespassory test may provide little guidance[,]” Justice Sotomayor opined that the unique attributes of GPS location surveillance will require careful application of the Katz analysis. Id.

She urged the Court to update its understanding of peoples’ expectations of privacy in the information age: GPS monitoring generates a precise, comprehensive record of a person’s public movements that reflects a wealth of detail about her familial, political, professional, religious, and sexual associations. See, e.g., People v. Weaver, 12 N.Y.3d 433, 441-442 , 882 N.Y.S.2d 357 , 909 N.E.2d 1195, 1199 (2009) (“Disclosed in [GPS] data ... will be trips the indisputably private nature of which takes little imagination to conjure: trips to the psychiatrist, the plastic surgeon, the abortion clinic, the AIDS treatment center, the strip club, the criminal defense attorney, the by-the-hour motel, the union meeting, the mosque, synagogue or church, the gay bar and on and on”). The Government can store such records and efficiently mine them for information years into the future. [United States v.] Pineda-Moreno, 617 F.3d [1120,] 1124 [ (9th Cir.2010) ] (opinion of Kozinski, C.J.). And because GPS monitoring is cheap in comparison to conventional surveillance techniques and, by design, proceeds surreptitiously, it evades the ordinary checks that constrain abusive law enforcement practices: “limited police resources and community hostility.” Illinois v. Lidster, 540 U.S. 419, 426 , 124 S.Ct. 885 , 157 L.Ed.2d 843 (2004).

Awareness that the Government may be watching chills associational and expressive freedoms. And the Government’s unrestrained power to assemble data that reveal private aspects of identity is susceptible to abuse. The net result is that GPS monitoring — by making available at a relatively low cost such a substantial quantum of intimate information about any person whom the Government, in its unfettered discretion, chooses to track — may “alter the relationship between citizen and government in a way that is inimical to democratic society.” United States v. Cuevas ³⁸⁸ Perez, 640 F.3d 272, 285 (C.A.7 2011) (Flaum, J., concurring). I would take these attributes of GPS monitoring into account when considering the existence of a reasonable societal expectation of privacy in the sum of one’s public movements.

I would ask whether people reasonably expect that their movements will be recorded and aggregated in a manner that enables the Government to ascertain, more or less at will, their political and religious beliefs, sexual habits, and so on. I do not regard as dispositive the fact that the Government might obtain the fruits of GPS monitoring through lawful conventional surveillance techniques. See Kyllo, 533 U.S. at 35, n. 2 , 121 S.Ct. 2038 ; ante, at 954 (leaving open the possibility that duplicating traditional surveillance “through electronic means, -without an accompanying trespass, is an unconstitutional invasion of privacy”). I would also consider the appropriateness of entrusting to the Executive, in the absence of any oversight from a coordinate branch, a tool so amenable to misuse, especially in light of the Fourth Amendment’s goal to curb arbitrary exercises of police power to and prevent “a too permeating police surveillance,” United States v. Di Re, 332 U.S. 581, 595 , 68 S.Ct. 222 , 92 L.Ed. 210 (1948).

Jones, 132 S.Ct. at 955-56 (Sotomayor, J., concurring) (footnote omitted). Justice Alito, concurring only in the judgment, disagreed with the majority’s reliance on a trespassory theory. Jones, 132 S.Ct. at 958. Instead, Justice Alito found the appropriate inquiry to be “whether respondent’s reasonable expectations of privacy were violated by the long-term monitoring of the movements of the vehicle he drove.” Id.

Justice Alito stated that the majority’s reasoning “disregarded] what is really important (the use of a GPS for the purpose of long-term tracking)” and “will present particularly vexing problems in cases involving surveillance that is carried out by making electronic, as opposed to physical, contact with the item to be tracked.” Id. at 962 (emphasis in original). ³⁸⁹ From the above precedent, we glean two broad principles regarding the Fourth Amendment analysis of surveillance technology. First, where surveillance technology is used without a warrant to obtain information about the contents of a home, not otherwise discernable without physical intrusion, there has been an unlawful search. See Kyllo, 533 U.S. at 34-35 , 121 S.Ct. 2038 . Second, where the government has engaged in surveillance using “electronic signals -without trespass[,]” the intrusion will “remain subject to Katz analysis.” Jones, 132 S.Ct. at 953 (emphasis in original).

The Supreme Court has recognized, however, that cell phones present novel privacy concerns. In Riley, supra, the Supreme Court made clear that a search of the information contained in a cell phone is subject to the warrant requirement regardless of its location. 134 S.Ct. at 2489-91 . The Court held that even during a search incident to arrest, the government must first obtain a warrant before searching the digital contents of a cell phone found on the person being arrested. Id. at 2485-86 .

Chief Justice Roberts described the modern cell phone as much more than a phone: Cell phones differ in both a quantitative and a qualitative sense from other objects that might be kept on an arrestee’s person. The term “cell phone” is itself misleading shorthand; many of these devices are in fact minicomputers that also happen to have the capacity to be used as a telephone. They could just as easily be called cameras, video players, rolodexes, calendars, tape recorders, libraries, diaries, albums, televisions, maps, or newspapers. One of the most notable distinguishing features of modern cell phones is their immense storage capacity.

Before cell phones, a search of a person was limited by physical realities and tended as a general matter to constitute only a narrow intrusion on privacy. Most people cannot lug around every piece of mail they have received for the past several months, every picture they have taken, or every book or article they have read — nor would they have any ³⁹⁰ reason to attempt to do so. And if they did, they would have to drag behind them a trunk of the sort held to require a search warrant in [U.S. v.] Chadwick, supra [ 433 U.S. 1 , 97 S.Ct. 2476 , 53 L.Ed.2d 538 (1977) ], rather than a container the size of the cigarette package in [U.S. v.] Robinson / 414 U.S. 218 , 94 S.Ct. 467 , 38 L.Ed.2d 427 (1973) ]. Id. at 2489.

The State argues that its use of the Hailstorm here should be analogized to Knotts, 460 U.S. 276 , 103 S.Ct. 1081 , wherein the Supreme Court upheld law enforcement officers’ use of a radio transmitter to track the movements of a container, by automobile, to a defendant’s home. In Knotts , the Court noted that “[t]he governmental surveillance conducted by means of the beeper in this case amounted principally to the following of an automobile on public streets and highways.” Id. at 281 , 103 S.Ct. 1081 . The Court concluded that: A person travelling in an automobile on public thoroughfares has no reasonable expectation of privacy in his movements from one place to another. When [the defendant] travelled over the public streets he voluntarily conveyed to anyone who wanted to look the fact that he was travelling over particular roads in a particular direction, the fact of whatever stops he made, and the fact of his final destination when he exited from public roads onto private property.

Id. at 281-82 , 103 S.Ct. 1081 . Here, the State argues that because Andrews’s cell phone was “constantly emitting ‘pings’ giving its location to the nearest cell tower, ... there can be no reasonable expectation of privacy in [that] information” under Knotts . The State’s reliance on Knotts , however, is misplaced. In Karo , the Supreme Court clarified that in Knotts the electronic device “told the authorities nothing about the interior of Knotts’ cabin.” 468 U.S. at 715 , 104 S.Ct. 3296 .

Rather, the information obtained in Knotts was “voluntarily conveyed to anyone who wanted to look[,]” id. (quoting Knotts, 460 U.S. at 281 , 103 S.Ct. 1081 ), and the subsequent search warrant was also supported by “intermittent visual surveillance” of the ³⁹¹ cabin, Knotts, 460 U.S. at 279 , 103 S.Ct. 1081 . As noted in Kyllo , the Supreme Court has long recognized that “[vjisual surveillance [i]s unquestionably lawful because ‘the eye cannot by the laws of England be guilty of a trespass.’ ” 533 U.S. at 31-32 , 121 S.Ct. 2038 (quoting Boyd v. United States, 116 U.S. 616, 628 , 6 S.Ct. 524 , 29 L.Ed. 746 (1886)). Here, there was no visual surveillance.

The mere fact that police could have located Andrews within the residence by following him as he travelled over public thoroughfares does not change the fact that the police did not know where he was, so they could not follow him. Unlike Knotts , the information obtained in this case did reveal at least one critical detail about the residence; i.e., that its contents included Andrews’s cell phone, and therefore, most likely Andrews himself. Further, “pings” from Andrews’s cell phone to the nearest tower were not available “to anyone who wanted to look.” We find the surreptitious conversion of a cell phone into a tracking device and the electronic interception of location data from that cell phone markedly distinct from the combined use of visual surveillance and a “beeper to signal the presence of [the defendant’s] automobile to the police receiver” to track a vehicle over public roads. See Knotts, 460 U.S. at 282 , 103 S.Ct. 1081 .

Put simply, the information obtained by police in this case was not readily available and in the public view as it was in Knotts . Cell site simulators, such as Hailstorm, can locate and track the movements of a cell phone and its user across both public and private spaces. Unchecked, the use of this technology would allow the government to discover the private and personal habits of any user. As Justice Sotomayor predicted in her concurring opinion in Jones, supra, we are compelled to ask “whether people reasonably expect that their movements will be recorded and aggregated in a manner that enables the Government to ascertain, more or less at will, their political and religious beliefs, sexual habits, and so on.” 132 S.Ct. at 956 (Sotomayor, J., concurring).

We conclude that they do not. ³⁹² We agree with the United States Court of Appeals for the Fourth Circuit in United States v. Graham, in declaring, “[w]e cannot accept the proposition that cell phone users volunteer to convey their location information simply by choosing to activate and use their cell phones and to carry the devices on their person.” 796 F.3d 332, 355 (4th Cir.), reh’g en banc granted, 624 Fed.Appx. 75 (4th Cir.2015). 16 Federal courts reviewing pen register\trap & trace applications have similarly recognized a reasonable expectation of privacy in cell site location information. See, e.g., In re the Application of the United States for an Order Authorizing (1) Installation and Use of a Pen Register and Trap and Trace Device or Process, (2) Access to Customer Records, and (3) Cell Phone Tracking, 441 F.Supp.2d 816 , 837 (S.D.Tex.2006) (“[D]etailed location information, such as triangulation and GPS data, ... unquestionably implicate Fourth Amendment privacy rights.”); In re Application of the United States for an Order Authorizing Installation and Use of a Pen Register and a Caller Identification System on Telephone Numbers (Sealed), 402 F.Supp.2d 597 , 604-05 (D.Md.2005) (recognizing that monitoring of cell phone location information is likely to violate a reasonable expectation of privacy). We also accept the circuit court’s finding in this case that “no one expects that their phone information is being sent directly to the police depart ³⁹³ ment on their apparatus.” 17 Recognizing that the Fourth Amendment protects people and not simply areas, Katz, 389 U.S. at 353 , 88 S.Ct. 507 , we conclude that people have a reasonable expectation of privacy in real-time cell phone location information. Moreover, because the use of the cell site simulator in this case revealed the location of the phone and Andrews inside a residence, we are presented with the additional concern that an electronic device not in general public use has been used to obtain information about the contents of a home, not otherwise discernable without physical intrusion.

See Kyllo, 533 U.S. at 34-35 , 121 S.Ct. 2038 . Under the applicable precedent, this is undoubtedly an intrusion that rises to the level of a Fourth Amendment “search.” See id. Indeed, “the Fourth Amendment draws a firm line at the entrance to the house[.]” Id. at 40 , 121 S.Ct. 2038 (citation and internal quotation marks omitted). Although we recognize that the use of a cell site simulator to track a phone will not always result in locating the phone within a residence, we agree with the Fourth Circuit’s observation that “the government cannot know in advance of obtaining this information how revealing it will be or whether it will detail the cell phone user’s movements in