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DISTRICT OF COLUMBIA COURT OF APPEALS

No. 15-CF-322

PRINCE JONES, APPELLANT, 

V.

UNITED STATES, APPELLEE. 

Appeal from the Superior Court

of the District of Columbia

(CF1-18140-13)

(Hon. Jennifer M. Anderson, Trial Judge)

(Argued April 18, 2017 Decided September 21, 2017) 

Stefanie Schneider, Public Defender Service, with whom Samia Fam and 

Jaclyn Frankfurt, Public Defender Service, were on the brief, for appellant.

Lauren R. Bates, Assistant United States Attorney, with whom Channing D. 

Phillips, United States Attorney, and Elizabeth Trosman, John P. Mannarino, and 

Jodi S. Lazarus, Assistant United States Attorneys, were on the brief, for appellee. 

Nathan Freed Wessler, American Civil Liberties Union, with whom Arthur 

B. Spitzer and Scott Michelman, American Civil Liberties Union, and Jennifer 

Lynch, Electronic Frontier Foundation, were on the brief, for American Civil 

Liberties Union of the Nation‘s Capital and Electronic Frontier Foundation, amicus 

curiae, in support of appellant. 

Before THOMPSON and BECKWITH, Associate Judges, and FARRELL, Senior 

Judge.

09/21/2017
2

Opinion by Associate Judge BECKWITH for the court, except as to Part II.E.3.

Opinion by Senior Judge FARRELL, concurring in part and concurring in the 

judgment, at page 47.

Dissenting opinion by Associate Judge THOMPSON, at page 54.

BECKWITH, Associate Judge: A jury found appellant Prince Jones guilty of 

various offenses arising out of two alleged incidents of sexual assault and robbery 

at knifepoint.1 Mr. Jones appeals his convictions on the ground that much of the 

evidence offered against him at trial was the direct or indirect product of a 

warrantless—and thus, Mr. Jones argues, unlawful—search involving a cell-site 

simulator or ―stingray.‖

2 Mr. Jones presented this Fourth Amendment claim to the 

trial court in a pretrial motion to suppress, but the trial court denied it under the 

 

1

 Mr. Jones was convicted of two counts of first-degree sexual abuse while 

armed, D.C. Code §§ 22-3002 (a)(1)–(2), -3020 (a)(5), -3020 (a)(6), -4502 (2012 

Repl.); two counts of kidnapping while armed, id. §§ 22-2001, -4502; four counts 

of robbery while armed, id. §§ 22-2801, -4502; and one count of threats, id. § 22-

1810. 

2

 The ―StingRay‖ is a popular cell-site simulator produced by the Harris 

Corporation. See Stephanie K. Pell & Christopher Soghoian, Your Secret 

Stingray’s No Secret Anymore: The Vanishing Government Monopoly over Cell 

Phone Surveillance and Its Impact on National Security and Consumer Privacy, 28 

Harv. J.L. & Tech. 1, 14 (2014). The name has become a generic term for a cellsite simulator. Kim Zetter, Hacker Lexicon: Stingrays, the Spy Tool the 

Government Tried, and Failed, to Hide, Wired (May 6, 2016), 

https://www.wired.com/2016/05/hacker-lexicon-stingrays-spy-tool-governmenttried-failed-hide/. The record in this case does not reveal the name of the device 

used against Mr. Jones; in the suppression hearing, the trial court sustained the 

government‘s objection to a question about the name of the device. 
3

inevitable-discovery doctrine3and did not reach the question whether the 

government violated Mr. Jones‘s rights. We agree with Mr. Jones that the 

government violated the Fourth Amendment when it deployed the cell-site 

simulator against him without first obtaining a warrant based on probable cause. 

Further, we reverse the trial court‘s inevitable-discovery ruling and reject the 

government‘s argument (not resolved by the trial court) that the good-faith 

doctrine4precludes applying the exclusionary rule in this case. Because the 

admission at trial of the evidence obtained as a result of the unlawful search was 

not harmless beyond a reasonable doubt, we reverse Mr. Jones‘s convictions.

I. Background

A. Investigation and Arrest of Mr. Jones

At the suppression hearing in this case, Detective Rachel Pulliam, a member 

of the Sexual Assault Unit of the Metropolitan Police Department (MPD), testified 

that she investigated a sexual assault that occurred around 12:30 a.m. on October 9, 

2013, and another that occurred around 1:30 a.m. on October 11. The two sexual-

 

3

 See Nix v. Williams, 467 U.S. 431 (1984).

4

 See United States v. Leon, 468 U.S. 897 (1984).
4

assault complainants were women who had advertised escort services on the 

classified-advertising website Backpage. Detective Pulliam testified that on each 

occasion, the perpetrator5contacted the complainant by telephone in response to an

advertisement and arranged to pay the complainant for sexual services. According 

to Detective Pulliam, when each complainant arrived at the arranged meeting 

place, the perpetrator ―forced [her] to perform oral sex on [him] at knifepoint‖ and 

robbed her of her cellphone and other property. Detective Pulliam testified that on 

one of the two occasions, the perpetrator also robbed the complainant‘s cousin, 

who had been waiting in a car outside the meeting location. 

Detective Pulliam testified that in the morning following the second 

incident, she and her colleagues obtained telephone records for the sexual-assault 

complainants. The telephone records revealed a possible suspect: Both 

complainants had received calls from the same number during the relevant time 

periods. Detective Pulliam sought the assistance of the MPD‘s Technical Services 

Unit (TSU) to track the suspect‘s and the complainants‘ phones. 

 

5

 Detective Pulliam referred to the perpetrator as ―the defendant,‖ but Mr. 

Jones was not known to the police at the time the complainants reported the crimes 

and only became known after the police tracked him down using the cell-site 

simulator.
5

Sergeant Todd Perkins, a supervisor in the TSU, testified about his office‘s 

efforts to track the phones that morning. He testified that he and his team sought 

―subscriber information‖ for the suspect‘s number from the provider associated 

with that number but were unsuccessful—the cellphone ―was just a generic 

prepaid‖ with ―no subscriber information whatsoever.‖ The TSU also sought and 

obtained information about the locations of the suspect‘s and complainants‘ 

cellphones from the relevant telecommunication providers.6 According to Sergeant 

Perkins, the TSU received updated location information from the providers every 

fifteen minutes. The information came in the form of geographic coordinates—

latitude and longitude—with a ―degree of uncertainty‖ specified in meters. 

Sergeant Perkins testified that the real-time location information they 

received that morning had a high degree of uncertainty—―several hundred 

meter[s]‖—indicating that the phones‘ GPS capabilities were inactive. He 

explained that ―if it [had been] true GPS,‖ his team would have been ―getting two 

meter, three meter, five meter hits.‖ Despite the lack of precision in the location 

information, Sergeant Perkins and his team were able to ―tell that . . . one of the 

 

6

 Officer Perkins testified that the TSU ―declared an exigent situation‖ and 

was therefore ―able to obtain the [real-time location] information without getting a 

warrant.‖ Officer Perkins admitted at the suppression hearing that his team had 

been operating under an erroneous belief that there had been a string of three 

sexual assaults by the same perpetrator within the preceding twenty-four hours. 
6

[complainants‘] phones and the [suspect‘s] phone were traveling in the same 

general direction . . . as if they were together.‖ The location information suggested

that the two phones stopped in the general vicinity of the Minnesota Avenue Metro 

Station. 

Based on this information, Sergeant Perkins and other TSU officers took a 

truck equipped with a cell-site simulator to the area of the Minnesota Avenue 

Metro station and used the device to track the suspect. Sergeant Perkins could not 

remember whether he and his team used the cell-site simulator to track the 

suspect‘s phone or the complainant‘s phone that they believed was traveling with 

it,7but whichever signal they were tracking led them, at around 11:30 a.m., to a 

parked Saturn. Inside the Saturn were Mr. Jones and Mr. Jones‘s girlfriend, Nora 

Williams. The police arrested Mr. Jones and recovered evidence from Mr. Jones‘s 

person and his car and from Ms. Williams, including a folding knife and the 

 

7

 As explained in the testimony summarized below, a cell-site simulator 

interferes with the target phone‘s ability to communicate with the cellular network. 

Records for the complainant‘s phone show that there was a single communication 

error around the time the TSU officers were operating the cell-site simulator, and 

Sergeant Perkins inferred from this—and from other circumstantial information—

that his team had probably been tracking the complainant‘s phone. Other 

evidence, however, suggested that the TSU may have been tracking the suspect‘s 

phone. In particular, records for the suspect‘s phone—which turned out to be Mr. 

Jones‘s phone—show seven failed calls during the relevant time period, and a data 

dump of the phone revealed that during that time period Mr. Jones sent a text 

message which said, ―Our call dropped.‖ 
7

complainants‘ and the suspect‘s cellphones. Mr. Jones also made an incriminating 

statement to the police. Ms. Williams later testified against Mr. Jones at trial.

B. Cell-Site Simulator

Sergeant Perkins testified at the suppression hearing about ―how [the cellsite simulator they used] works,‖ ―based on the information that‘s publicly 

available.‖ He explained that his team engages the cell-site simulator by 

programming into it a unique identifier—an MIN or IMSI number8—associated 

with the target phone.9 The simulator then begins ―listening for [the target] 

phone,‖ which, as part of its normal operation, is ―constantly transmitting to and 

receiving from a tower.‖ The officers operating the cell-site simulator drive 

around and ―as soon as [the simulator] comes across [the target phone‘s signal], it 

 

8

 These identifying numbers are distinct from the seven- or ten-digit number 

that a person dials when he or she places a call. Sergeant Perkins testified that the 

TSU receives these numbers by requesting ―subscriber information‖ for a phone 

number. He explained that ―MIN‖ stands for ―mobile identification number‖ and 

is the identifying number used by ―Verizon, Cricket and Sprint‖ and that ―IMSI‖ 

stands for ―international mobile subscriber identification‖ and is used by ―TMobile and AT&T.‖ 

9

 Sergeant Perkins testified that it is also possible to enter multiple 

identifying numbers into the cell-site simulator. In this operating mode, he 

explained, ―the equipment will just let us know one of those phones is present in 

the area‖ but will not provide location information. 
8

grabs it and it holds on to it.‖ Once the cell-site simulator ―grabs‖ the target 

phone, the simulator begins reporting ―general location information and signal 

strength‖ that can be used to locate the target phone‘s exact location.10 Sergeant 

Perkins testified that once the cell-site simulator ―grabs‖ the target phone, the 

target phone is prevented from communicating ―with an actual . . . tower.‖ 

Further information about the cell-site simulator was provided by Ben 

Levitan, an expert on ―cellular telephone networks and systems‖ called by the 

defense.11 According to Mr. Levitan, cell phones are ―dumb devices‖ that 

―generally connect themselves to the strongest cell tower signal that they detect.‖ 

Mr. Levitan explained that a cell-site simulator ―act[s] as a portable cell tower,‖ 

which, ―when turned on or brought into an area, may appear to be a stronger signal 

and cause [a] phone[] to break its connection with the cell phone network and 

 

10

 Sergeant Perkins explained the search process thus:

[T]here is a directional antenna, . . . so we‘re driving this 

way, the directional antenna knows the signal is coming 

from over here, so we know the phone‘s coming over 

there. And then it also measures the signal strength from 

the phone, so if the signal strength is real, real low, it‘s 

probably somewhere behind you. 

11

 The defense also submitted an affidavit by Mr. Levitan, which Mr. 

Levitan ―adopt[ed] . . . as part of [his] testimony,‖ without objection by the 

government. 
9

reattach itself to the newly found . . . simulator.‖12 Mr. Levitan testified that when 

the cellphone ―attach[es]‖ itself to the cell-site simulator, it ―identifies itself by 

phone number and various codes,‖ including its IMSI number.13 Although Mr. 

Levitan had never used the type of cell-site simulator utilized by law enforcement, 

he testified that he had used similar devices working within the 

telecommunications industry and that the devices allow the user to determine the 

target phone‘s direction and distance relative to the simulator device.14 Moreover, 

because the cell-site simulator is not a true cell tower connected with the cellular 

network, any cellphone connected to the cell-site simulator will not be able to 

communicate with the network: ―[Y]our call doesn‘t go through[,] period. 

 

12

 Mr. Levitan testified that a cell-site simulator causes not only the target 

phone, but ―[a]ll cell phones that are in the vicinity,‖ to ―attach . . . to the newly 

found . . . simulator.‖ 

13

 Cell-site simulators are sometimes referred to as ―IMSI catchers.‖ Pell & 

Soghoian, supra note 2, at 11. 

14

 Mr. Levitan testified that when a cellphone is communicating with a 

legitimate cellular tower, it communicates with a particular sector antenna of the

tower, and that the provider can thus determine ―what side of the cell tower‖ the 

cellphone is on. Mr. Levitan indicated that cell-site simulators measure direction 

through a similar method. But see supra note 10 (Sergeant Perkins describing a 

somewhat different method of determining direction). And Mr. Levitan testified 

that a cell-site simulator can determine distance through a ―trick‖ in which it 

―send[s] . . . a signal [to the phone] and ask[s] it to send . . . the signal back.‖ By 

―measur[ing] th[e] round trip time,‖ the distance between the cell-site simulator 

and the phone can be determined. 
10

Nothing happens.‖15 

C. Trial Court’s Ruling on the Motion To Suppress

In ruling on Mr. Jones‘s motion to suppress, the trial court did not decide 

whether the use of a cell-site simulator was a search within the meaning of the 

Fourth Amendment or whether the government was required to obtain a warrant to 

use the cell-site simulator. Instead, the trial court focused on the issues of 

standing, exigent circumstances, and inevitable discovery.

 

15

 We note that both witnesses‘ testimony about the cell-site simulator is 

consistent with information in a Department of Justice memorandum on such 

devices. See Dep‘t of Justice Policy Guidance: Use of Cell-Site Simulator 

Technology (Sept. 3, 2015), https://www.justice.gov/opa/file/767321/download. 

The memorandum explains:

Cell-site simulators . . . function by transmitting as a cell 

tower. In response to the signals emitted by the 

simulator, cellular devices in the proximity of the device 

identify the simulator as the most attractive cell tower in 

the area and thus transmit signals to the simulator that 

identify the device in the same way that they would with 

a networked tower. 

Id. at 2. Once the target cellphone is identified, the cell-site simulator ―provide[s] 

. . . the relative signal strength and general direction‖ of the phone. Id. The 

memorandum notes that the cell-site simulator can cause ―cellular devices in the 

area [to] experience a temporary disruption of service from the service provider.‖ 

Id. at 5.
11

On the issue of standing, the trial court stated that the suppression-hearing 

record did not reveal ―with any great degree of certainty‖ which phone—Mr. 

Jones‘s or the complainant‘s—the police had tracked using the cell-site simulator. 

The court believed that the burden was on the government to show that the police 

did not track Mr. Jones‘s phone and found that the government had failed to meet 

this burden. The government did not take issue with this allocation of the burden 

of proof and agreed with the court‘s determination.

16

 

The trial court rejected the government‘s argument that there were exigent 

circumstances justifying noncompliance with any otherwise applicable warrant 

requirement—though, again, the trial court did not determine whether there was a 

warrant requirement. The court noted that significant time (around ten hours) had 

passed between the sexual assault and the arrest of Mr. Jones on October 11, 

during which time ―the detectives could have been getting a warrant.‖

 The trial court agreed with the government‘s argument that regardless of 

whether there had been a Fourth Amendment violation, the inevitable-discovery 

 

16

 The government has reversed course in this appeal and is now arguing 

that Mr. Jones bore the burden of proving that the government searched his phone 

and failed to meet this burden. But because the government affirmatively—and 

repeatedly—conceded the standing issue in the trial court, the government has 

waived this argument. 
12

doctrine rendered the exclusionary rule inapplicable. The court found that ―even if 

[the police] were using [Mr. Jones‘s] phone on the cell site simulator, . . . had they 

switched over . . . to use the [complainant‘s] number instead, . . . they would have 

eventually gotten to the exact same place because the phones were together[ a]nd 

it‘s the same technology.‖ The court thus agreed with the government‘s assertion

that ―there[ was] a separate lawful means‖ by which the government ―would have 

gotten to the exact same place.‖ 

II. Discussion

Mr. Jones claims that the government‘s use of a cell-site simulator violated 

his Fourth Amendment rights and that the trial court erred in failing to grant his 

motion to suppress. In deciding this Fourth Amendment claim, we defer to the 

trial court‘s factual findings and review them only for clear error, but we review 

the trial court‘s legal conclusions de novo. (Albert) Jones v. United States, 154 

A.3d 591, 594 (D.C. 2017). The Fourth Amendment protects the ―right of the 

people to be secure in their persons, houses, papers, and effects, against 

unreasonable searches and seizures,‖ and thus we turn first to the threshold 

question whether the government‘s use of the cell-site simulator to locate Mr. 
13

Jones‘s cellphone17 constituted a search or seizure.

A. Fourth Amendment Search

Government conduct is a ―search‖ within the meaning of the Fourth 

Amendment if it invades ―an actual (subjective) expectation of privacy . . . that 

society is prepared to recognize as reasonable.‖ Katz v. United States, 389 U.S. 

347, 361 (1967) (Harlan, J., concurring) (internal quotation marks omitted); see 

also Kyllo v. United States, 533 U.S. 27, 33 (2001); Napper v. United States, 22 

A.3d 758, 767 (D.C. 2011). In deciding whether a particular expectation of 

privacy is ―reasonable,‖ this court aims to ―assure[] preservation of that degree of 

privacy against government that existed when the Fourth Amendment was 

adopted.‖ Kyllo, 533 U.S. at 34. ―To withdraw protection of this minimum 

expectation would be to permit police technology to erode the privacy guaranteed 

by the Fourth Amendment.‖ Id.

Our analysis begins with the obvious fact that most people have a cellphone 

 

17

 We consider it conceded that the government deployed the cell-site 

simulator on Mr. Jones‘s phone rather than on one of the complainants‘ phones. 

See supra notes 7 & 16, as well as the accompanying text. 
14

and carry it with them practically everywhere they go.

18

 One consequence of this 

is that locating and tracking a cellphone using a cell-site simulator has the 

substantial potential to expose the owner‘s intimate personal information. First, 

―cell phone tracking can easily invade the right to privacy in one‘s home or other 

private areas.‖ Tracey v. State, 152 So. 3d 504, 524 (Fla. 2014); see also State v. 

Earls, 70 A.3d 630, 642 (N.J. 2013) (―[C]ell phones . . . blur the historical 

distinction between public and private areas because [they] emit signals from both 

places.‖). When this occurs, there is a ―clear[] . . . Fourth Amendment violation.‖ 

Tracey, 152 So. 3d at 524; see also United States v. Karo, 468 U.S. 705, 714 

(1984) (―[P]rivate residences are places in which the individual normally expects 

privacy free of governmental intrusion not authorized by a warrant, and that 

expectation is plainly one that society is prepared to recognize as justifiable.‖). 

And second, even a person‘s public movements, as observed by a cell-site 

simulator or other means of cellphone tracking, can reveal sensitive information 

about the person‘s ―familial, political, professional, religious, and sexual 

associations.‖ United States v. (Antoine) Jones, 565 U.S. 400, 415 (2012) 

(Sotomayor, J., concurring).

 

18

 See Riley v. California, 134 S. Ct. 2473, 2490 (2014) (―[I]t is the person 

who is not carrying a cell phone . . . who is the exception. According to one poll, 

nearly three-quarters of smart phone users report being within five feet of their 

phones most of the time . . . .‖). 
15

Another consequence of cellphones‘ ―pervasiveness‖19 is that a cell-site 

simulator can be used by the government not merely to track a person but to locate

him or her. See State v. Andrews, 134 A.3d 324, 348 (Md. Ct. Spec. App. 2016). 

Police have always had the capacity to visually track a suspect from some starting 

location, and electronic tracking devices like those used in United States v. Knotts, 

460 U.S. 276 (1983), and Karo, 468 U.S. 705, have augmented this preexisting 

capacity. But although the kind of device used in Knotts and Karo is probably 

more reliable than a human tracker—less prone to discovery than a human and 

harder to elude—at their core these devices merely enable police officers to 

accomplish the same task that they could have accomplished through ―[v]isual 

surveillance from public places.‖ Knotts, 460 U.S. at 282; see also Karo, 468 U.S. 

at 713. This is because the tracking device must be physically installed on some 

object that the target will later acquire or use. See, e.g., (Antoine) Jones, 565 U.S. 

at 402–03 (GPS tracker placed on the defendant‘s wife‘s car); Karo, 468 U.S. at 

708 (tracker placed in container of chemicals the defendant had purchased); 

Knotts, 460 U.S. at 276 (same). These devices do not enable police to locate a 

person whose whereabouts were previously completely unknown.

With a cell-site simulator, however, police no longer need to track a person 

 

19

 Riley, supra note 18, 134 S. Ct. at 2490.
16

visually from some starting location or physically install a tracking device on an 

object that is in, or will come into, his or her possession. Instead, they can 

remotely activate the latent tracking function of a device that the person is almost 

certainly carrying in his or her pocket or purse: a cellphone. As the present case 

demonstrates, police officers first obtain subscriber information and real-time 

location information from the target‘s telecommunications provider to narrow 

down the search area.

20 They then proceed to that area with a cell-site simulator, 

 

20

 Mr. Jones has not argued in this appeal that the government violated his 

Fourth Amendment rights when it obtained real-time cell-site location information 

(CSLI) for his phone from his telecommunications provider. Also not involved in 

this case is historical CSLI—location information maintained by cellular 

companies in the ordinary course of business. Some courts have held that the 

Fourth Amendment protects real-time CSLI, e.g., Tracey, 152 So. 3d at 523, but 

many have held that the Fourth Amendment does not protect historical CSLI, e.g., 

United States v. Graham, 824 F.3d 421, 427–28 (4th Cir. 2016) (en banc). See 

generally Eric Lode, Annotation, Validity of Use of Cellular Telephone or Tower 

to Track Prospective, Real Time, or Historical Position of Possessor of Phone 

Under Fourth Amendment, 92 A.L.R. Fed. 2d 1 (2015). The Fourth Amendment 

analysis for real-time and historical CSLI disclosed by a telecommunications 

provider is complicated by uncertainty about the applicability and scope of the 

third-party doctrine. Compare Graham, 824 F.3d at 427–28 (―Each time 

Defendants made or received a call, or sent or received a text message—activities 

well within the  ̳ordinary course‘ of cell phone ownership—[their provider] 

generated a record of the cell towers used . . . . Having  ̳exposed‘ the CSLI to 

[their provider], Defendants here, like the defendant in Smith,  ̳assumed the risk‘ 

that the phone company would disclose their [historical CSLI] to the government.‖ 

(quoting Smith v. Maryland, 444 U.S. 735, 744 (1979))), with In re United States 

for an Order Authorizing the Release of Historical Cell-Site Info., 809 F. Supp. 2d 

113, 126 (E.D.N.Y. 2011) (―[T]he court concludes that established normative 

privacy considerations support the conclusion that the reasonable expectation of 

privacy is preserved here, despite the fact that cell-site-location records [are] 

(continued...)
17

which they use to force the person‘s cellphone to identify itself and reveal its exact 

location. It is in this sense that a cell-site simulator is a locating, not merely a 

tracking, device: A cell-site simulator allows police officers who possess a 

person‘s telephone number to discover that person‘s precise location remotely and 

at will. 

A final consideration is that when the police use a cell-site simulator to 

locate a person‘s cellphone, the simulator does not merely passively listen for 

transmissions sent by the phone in the ordinary course of the phone‘s operation. 

Instead, the cell-site simulator exploits a security vulnerability in the phone—the 

fact that cellphones are, in the words of the defense expert, ―dumb devices,‖ unable 

to differentiate between a legitimate cellular tower and a cell-site simulator 

masquerading as one

21—and actively induces the phone to divulge its identifying 

information. Once the phone is identified, it can be located. So far as the present 

record reveals, the only countermeasure that a person can undertake is to turn off 

 

(...continued)

disclosed to cell-phone service providers.‖). The third-party doctrine has no 

application in the present case, however, because the police‘s use of a cell-site 

simulator is ―direct government surveillance.‖ Graham, 824 F.3d at 426 & n.4.

21

 See also Pell & Soghoian, supra note 2, at 12 (explaining that active 

surveillance devices exploit the lack of an authentication mechanism in the 2G 

phone protocol design).
18

his or her cellphone or its radios (put it in ―airplane mode‖), thus forgoing its use 

as a communication device. 

The preceding considerations lead us to conclude that the use of a cell-site 

simulator to locate Mr. Jones‘s phone invaded a reasonable expectation of privacy 

and was thus a search. First, given the potential for location information gathered 

by a cell-site simulator or other device to reveal sensitive personal facts, people 

justifiably seek to keep such information private. This is insufficient, in itself, to 

support our conclusion that the government invaded a legitimate expectation of 

privacy: Supreme Court precedent makes clear that certain forms of tracking do 

not invade a reasonable expectation of privacy. See Knotts, 460 U.S. at 282 

(holding that the use of an electronic device to track a suspect‘s movements in 

public spaces did not invade a reasonable expectation of privacy);22 see also Karo, 

468 U.S. at 719 (holding that the unlawful use of a device to track movements 

inside a residence did not necessarily taint the otherwise lawful use of the same 

device to track the suspects in public).

 

22

 But see (Antoine) Jones, 565 U.S. at 416 (Sotomayor, J., concurring) (―I 

do not regard as dispositive the fact that the Government might obtain the fruits of 

GPS monitoring through lawful conventional surveillance techniques.‖); id. at 430 

(Alito, J., concurring in judgment) (―[T]he use of longer term GPS monitoring in 

investigations of most offenses impinges on expectations of privacy.‖).
19

But in addition to the fact that people reasonably value and hope to protect 

the privacy of their location information, what necessitates our conclusion is the 

method by which the government obtained the location information in this case. 

See Kyllo, 533 U.S. at 35 n.2 (―The fact that equivalent information could 

sometimes be obtained by other means does not make lawful the use of means that 

violate the Fourth Amendment.‖); United States v. Maynard, 615 F.3d 544, 566 

(D.C. Cir. 2010) (―[W]hen it comes to the Fourth Amendment, means do matter.‖), 

aff’d on other grounds by (Antoine) Jones, 565 U.S. 400. Unlike in a situation in 

which the government determines a person‘s location through visual surveillance 

or by employing the older generation of tracking devices, see Karo, 468 U.S. at 

719; Knotts, 460 U.S. at 282, it cannot be argued that ―the information obtained by 

[the government] in this case was . . . readily available and in the public view,‖ 

Andrews, 134 A.3d at 348. The cell-site simulator employed in this case gave the 

government a powerful person-locating capability that private actors do not have

and that, as explained above, the government itself had previously lacked—a 

capability only superficially analogous to the visual tracking of a suspect.23 And

 

23

 We are accordingly unpersuaded by one court‘s suggestion that using 

cellular technology to track a suspect is analogous to using ―dogs . . . to track a 

fugitive . . . [by] his scent.‖ United States v. Skinner, 690 F.3d 772, 777 (6th Cir. 

2012). And our dissenting colleague‘s suggestion that the search here was 

permitted under the automobile exception to the Fourth Amendment, see post at 

86–88, is similarly unconvincing. The dissent argues that under the automobile 

(continued...)
20

the simulator‘s operation involved exploitation of a security flaw in a device that 

most people now feel obligated to carry with them at all times. Allowing the 

government to deploy such a powerful tool without judicial oversight would surely 

―shrink the realm of guaranteed privacy‖ far below that which ―existed when the 

Fourth Amendment was adopted.‖ Kyllo, 533 U.S. at 34. It would also place an

individual in the difficult position either of accepting the risk that at any moment 

his or her cellphone could be converted into tracking device or of forgoing 

―necessary use of‖ the cellphone. Tracey, 152 So. 3d at 523. We thus conclude 

that under ordinary circumstances, the use of a cell-site simulator to locate a person

through his or her cellphone invades the person‘s actual,24 legitimate, and 

 

(...continued)

exception, police officers could have searched Mr. Jones‘s car without a warrant 

and seized ―any cell phones in it that might have been contraband or evidence of 

the crime.‖ Post at 88. From this, the dissent claims, it follows that the police had 

the right to use the cell-site simulator to search or seize Mr. Jones‘s phone. This 

argument glosses over the fact that what the cell-site simulator obtained was Mr. 

Jones‘s location information. When police search a car under the automobile 

exception, by contrast, they do not obtain location information—they already know

the car‘s location if they are searching it. The dissent also glosses over the fact that 

the police need probable cause to search a car under the automobile exception. 

Tuckson v. United States, 77 A.3d 357, 366 (D.C. 2013). The police here did not 

have probable cause to believe that there was evidence of a crime inside Mr. 

Jones‘s car until they used the cell-site simulator to locate Mr. Jones‘s cellphone.

24

 Ordinarily, a person need not do anything affirmative to exhibit an actual 

subjective expectation that he or she will not be located and tracked by a cell-site 

simulator. In Katz, the defendant was ―entitled to assume‖ that his phone 

conversation was private based purely on the fact that he had ―occupie[d] [the 

(continued...)
21

reasonable expectation of privacy in his or her location information and is a search. 

The government‘s argument to the contrary is unpersuasive. The 

government contends that because a cellphone ―must continuously broadcast a 

signal,‖ a person who carries or uses a cellphone is engaging in ―conduct [that] is 

not calculated to keep [his] location private and . . . thus[] has no reasonable 

expectation of privacy in his location.‖ The government cites for support United 

States v. Wheeler, 169 F. Supp. 3d 896 (E.D. Wis. 2016), in which the court found

that ―today, when many Americans own some sort of cell phone and carry it 

frequently, an individual‘s expectation that the government could not track his 

whereabouts over time is [not] reasonable.‖ Id. at 908; see also id. (―The media is 

rife with information—and sometimes warnings—about the fact that one‘s location 

can be tracked from one‘s cell phone.‖).25 This line of reasoning rests on a 

 

(...continued)

phone booth], shut[] the door behind him, and pa[id] the toll.‖ 389 U.S. at 352. 

Likewise, in Kyllo, the Supreme Court found that the use of a thermal imager on 

the defendant‘s home violated an expectation of privacy, without any discussion 

about whether the defendant had taken measures to thwart the effectiveness of the 

device. 533 U.S. at 40. But in fact in the present case, there was some evidence 

that Mr. Jones affirmatively sought to keep his location information private: His 

phone‘s GPS feature (to the extent it existed) had been disabled.

25

 The government also cites United States v. Caraballo, 831 F.3d 95 (2d 

Cir. 2016), cert. denied, 137 S. Ct. 654 (2017), a case in which the police obtained 

real-time cell-site location information without a warrant. See supra note 20. The 

court approved the officers‘ actions under the exigency exception. Caraballo, 831 

(continued...)
22

misreading of the Katz expectation-of-privacy test that construes the test as 

involving a probabilistic inquiry (an inquiry into whether it is likely—or the public 

thinks it is likely—that the government can access the information in question)

rather than a normative one (an inquiry into whether it is consistent with the 

nation‘s traditions and values that the government should have unfettered access to 

the information).

26

 Contrary to the government‘s argument, Katz makes clear that 

 

(...continued)

F.3d at 106. The court stated that ―any expectation of privacy that [the defendant] 

had in his cell-phone location was dubious at best.‖ Id. at 105. But this remark 

was part of a broader exigency analysis, and the court‘s primary justification for it 

was the lack of decisive authority on the question. See id. at 106 (―[T]he fact that 

the question of the degree of privacy that adheres to these sorts of information, to 

date, divides those Circuit courts that have spoken to the issue reinforces the 

conclusion that the intrusion here was not to an established, core privacy value.‖).

26 Moreover, the factual premise of the government‘s argument is 

erroneous. The events at issue in this case occurred in 2013, and at that time cellsite simulators were relatively unknown to the public. Law-enforcement agencies 

around the country that acquired the device had been required (and, for all we 

know, still continue to be required) to sign nondisclosure agreements with the 

Federal Bureau of Investigation. See Matt Richtel, A Police Gadget Tracks 

Phones? Shhh! It’s Secret, N.Y. Times, Mar. 15, 2015, https://www.nytimes.com/ 

2015/03/16/business/a-police-gadget-tracks-phones-shhh-its-secret.html; Pell & 

Soghoian, supra note 2, at 38. Indeed, amici curiae have provided us with a 

redacted copy of a nondisclosure agreement that the MPD signed. By signing this 

agreement, the MPD agreed that, among other things, ―the equipment/technology 

and any information related to its functions, operation, and use shall . . . [not be] 

disclos[ed] . . . to the public in any manner including but not limited to: in press 

releases, in court documents, during judicial hearings, or during other public 

forums.‖ See also Andrews, 134 A.3d at 338 (detailing a similar agreement signed 

by the Baltimore City Police Department). There is no evidence in the record that 

Mr. Jones was aware of the government‘s secret use of the cell-site simulator and 

(continued...)
23

a person does not lose a reasonable expectation of privacy merely because he or 

she is made aware of the government‘s capacity to invade his or her privacy. 

When Katz was issued, the public and the courts were well aware of the 

government‘s capacity to wiretap and eavesdrop through technological means, yet 

the Supreme Court did not find this fact determinative of the question whether 

individuals possess a reasonable expectation of privacy in their conversations. See 

Katz, 389 U.S. at 352 (citing Olmstead v. United States, 277 U.S. 438 (1928) 

(wiretapping), and Goldman v. United States, 316 U.S. 129 (1942) (bugging)); see 

also Susan Freiwald, First Principles of Communications Privacy, 2007 Stan. 

Tech. L. Rev. 3, 28 (―In the several years preceding Katz, the public had learned of 

rampant illegal wiretapping from numerous influential books, scholarly articles, 

and newspaper accounts.‖). A person‘s awareness that the government can locate 

and track him or her using his or her cellphone likewise should not be sufficient to 

negate the person‘s otherwise legitimate expectation of privacy. See also Smith v. 

Maryland, 442 U.S. 735, 741 n.5 (1979) (―[W]here an individual‘s subjective 

expectations ha[ve] been  ̳conditioned‘ by influences alien to well-recognized 

Fourth Amendment freedoms, those subjective expectations obviously could play 

no meaningful role in ascertaining what the scope of Fourth Amendment protection 

 

(...continued)

little reason to believe that the public was widely aware of it.
24

[is].‖); 1 Wayne R. LaFave, Search and Seizure: A Treatise on the Fourth 

Amendment § 2.1 (d) (5th ed. 2016) (―[W]hat is involved here is  ̳our societal 

understanding‘ regarding what deserves  ̳protection from government invasion.‘‖ 

(quoting Oliver v. United States, 466 U.S. 170, 178 (1984))).

The government‘s use of the cell-site simulator to locate Mr. Jones was 

therefore a search.27 The government did not obtain a warrant and has not argued 

 

27

 We need not rule on Mr. Jones‘s alternative argument that the 

government‘s conduct here constituted a search under (Antoine) Jones, 565 U.S. 

400, where the court held that a trespass used to obtain information constitutes a 

Fourth Amendment search. Mr. Jones makes a plausible argument that the 

government‘s conduct constituted a trespass to his chattel—that is, that the 

government ―intentionally . . . us[ed] or intermeddl[ed]‖ with his chattel, his 

cellphone. Restatement (Second) of Torts § 217 (Am. Law Inst. 1965). The 

government, through the cell-site simulator, coopted Mr. Jones‘s phone, forcing it 

to do something Mr. Jones surely never intended it to do: reveal its identifying and 

location information to an entity other than a telecommunications provider. 

Moreover, it is a natural consequence of a cell-site simulator‘s use that it will 

disrupt the operation of the target phone, and there is reason to believe that this 

happened here, given the records showing Mr. Jones‘s seven failed calls. See 

supra note 7. And numerous courts have held that computer hacking and 

interference with electronic resources can satisfy the elements of common-law 

trespass to chattels. See generally Marjorie A. Shields, Annotation, Applicability 

of Common-Law Trespass Actions to Electronic Communications, 107 A.L.R.5th 

549 (2003). 

But the question whether the holding of (Antoine) Jones extends beyond 

physical trespasses is still an open one. It is unclear, first of all, whether the 

holding of (Antoine) Jones depends on ―the law of trespass as it existed at the time 

of the adoption of the Fourth Amendment‖ or whether new forms of the tort are 

relevant. 565 U.S. at 426 (Alito, J., concurring in judgment). Assuming that the 

former is the case, it is also not clear whether ―the[] recent decisions [recognizing 

(continued...)
25

that the search ―f[ell] within a specific exception to the warrant requirement,‖ and 

therefore the search was unlawful under the Fourth Amendment. United States v. 

Riley, 134 S. Ct. 2473, 2482 (2014); see also United States v. Lewis, 147 A.3d 236, 

239 (D.C. 2016) (en banc) (―A search conducted without a warrant is per se 

unreasonable under the Fourth Amendment unless it falls within a few specific and 

well-established exceptions.‖ (quoting United States v. Taylor, 49 A.3d 818, 821 

(D.C. 2012))).

28

 

 

(...continued)

electronic trespass to chattels] represent a change in the law or simply the 

application of the old tort to new situations.‖ Id. at 426–27 (Alito, J., concurring in 

judgment). Mr. Jones‘s counsel pointed out during oral argument that courts 

recognized forms of nonphysical trespass on chattels long before the electronic 

age, suggesting a possible answer to the second of these questions. See, e.g., Cole 

v. Fisher, 11 Mass. 137 (1814) (holding that the plaintiff could sue for trespass to 

chattels where the sound of the defendant‘s gunshot frightened the plaintiff‘s 

horse, resulting in damage to the plaintiff‘s carriage); see also W. Page Keeton et 

al., Prosser and Keeton on Torts § 14 n.8 (5th ed. 1984) (citing other cases). Yet 

we do not have to answer these ―vexing‖ questions today. (Antoine) Jones, 565 

U.S. at 426 (Alito, J., concurring in judgment).

28

 Arguing that ―bystanders[‘] . . . phones [can be] ensnared by the cell site 

simulator,‖ see supra notes 12 and 15, amici curiae ask us to adopt a requirement 

that ―any cell site simulator warrant must include provisions to minimize 

collection, retention, and use of bystanders‘ data.‖ See In re Application of the 

United States for an Order Relating to Telephones Used by Suppressed, No. 15 M 

0021, 2015 WL 6871289, at *3–4 (N.D. Ill. Nov. 9, 2015); In re Search Warrant, 

71 A.3d 1158, 1170 (Vt. 2012) (―Warrants for electronic surveillance routinely set 

out  ̳minimization‘ requirements—procedures for how and under what conditions 

the electronic surveillance may be conducted—in order to  ̳afford similar 

protections to those that are present in the use of conventional warrants authorizing 

(continued...)
26

Our conclusion that the government violated Mr. Jones‘s Fourth 

Amendment rights is not the end of our inquiry. We must decide whether Mr. 

Jones is entitled to a remedy, and if so what the scope of that remedy should be. 

As a general matter, the ―[e]xclusionary rule . . . forbids the use of improperly 

obtained evidence at trial.‖ Herring v. United States, 555 U.S. 135, 139 (2009). 

―[T]his judicially created rule is  ̳designed to safeguard Fourth Amendment rights 

generally through its deterrent effect.‘‖ Id. at 139–40 (quoting United States v. 

Calandra, 414 U.S. 338, 348 (1974)). The government argues that the 

exclusionary rule does not apply in this case, invoking the inevitable-discovery 

doctrine, good-faith exception, and a change in its policies concerning the use of 

cell-site simulators. The government also argues that much of the evidence that 

Mr. Jones wants excluded does not fall within the scope of the exclusionary rule—

that it is not ―fruit of the poisonous tree.‖ Wong Sun v. United States, 371 U.S. 

471, 488 (1963). We first address the inevitable-discovery doctrine.

B. Inevitable-Discovery Doctrine

 

(...continued)

the seizure of tangible evidence.‘‖ (quoting Berger v. New York, 388 U.S. 41, 57 

(1967)) (brackets removed)). The issue of interference with third parties‘ phones is 

not before us in this appeal, however. 
27

The inevitable-discovery doctrine ―shields illegally obtained evidence from 

the exclusionary rule if the government can show, by a preponderance of the 

evidence, that the evidence  ̳ultimately or inevitably would have been discovered 

by lawful means.‘‖ Gore v. United States, 145 A.3d 540, 548 (D.C. 2016) (quoting 

Hicks v. United States, 730 A.2d 657, 659 (D.C. 1999)); see also Nix v. Williams, 

467 U.S. 431 (1984). To avail itself of the inevitable-discovery doctrine, the 

government must prove two distinct elements: (1) that ―the lawful process which 

would have ended in the inevitable discovery . . . ha[d] commenced before the 

constitutionally invalid seizure,‖ and (2) that there is a ― ̳requisite actuality‘ that 

the discovery would have ultimately been made by lawful means.‖ Hicks, 730 

A.2d at 659 (quoting Douglas-Bey v. United States, 490 A.2d 1137, 1139 n.6 (D.C. 

1985), and Hilliard v. United States, 638 A.2d 698, 707 (D.C. 1994)) (brackets and 

ellipsis removed).

The trial court found that ―had [the police] switched [the cell-site simulator] 

over to use the [complainant‘s phone] . . . they would have eventually gotten to the 

exact same place because the phones were together.‖ Assuming for the sake of 

argument that the hearing evidence supports this finding,

29 we agree with the trial 

 

29

 Mr. Jones argues that this finding was clearly erroneous because ―[t]he 

government presented no expert testimony about the functioning of the cell site 

(continued...)
28

court that this finding justifies a conclusion that there was a separate lawful means 

by which the police could have captured Mr. Jones and recovered the evidence 

used against him at trial.30 The finding is insufficient, however, to support a 

conclusion that the police would have captured Mr. Jones—which is what the 

inevitable-discovery doctrine requires.

 The undisputed evidence in the record shows that the MPD possessed only 

a single operating cell-site simulator,31 and that it could only be used to locate a 

single phone at a time. The police used it to search for Mr. Jones‘s cellphone.

Thus, the police‘s search for the complainant‘s cellphone—the lawful process—

never occurred. If the lawful search never occurred, it did not ―commence[] before

 

(...continued)

simulator, choosing instead to present only lay testimony [by Sergeant Perkins] 

about how the field operators use the device.‖ In Mr. Jones‘s view, ―there is no 

evidence in the record about the failure rate of the cell site simulator or whether it 

statistically works better with certain models of phones or on certain networks.‖ 

30

 In this regard, we note that not only did Mr. Jones concede that he lacked 

standing to contest a search involving the complainant‘s phone, but also the record 

suggests that the complainant consented to the police‘s tracking of her phone. See 

United States v. Johnson, 380 F.3d 1013, 1017 (7th Cir. 2004) (holding that to rely 

on the inevitable-discovery doctrine the government must prove a lawful means by 

which it would have obtained the evidence, and that it is insufficient to prove 

merely that ―the evidence would have been discovered as a consequence of [an] 

illegal search of [a third party], to which [the defendant] could not object‖).

31

 The MPD owned another unit, but it was not working properly the day of 

the search. 
29

the constitutionally invalid seizure‖ of Mr. Jones. Hicks, 730 A.2d at 659 (quoting

Douglas-Bey, 490 A.2d at 1139 n.6).

The government disagrees with this conclusion and argues that because the 

police had tracked the complainant‘s phone using real-time location information 

from the provider and had obtained her phone‘s identifying information, they ―had 

begun the process necessary to locate her phone with the cell-[s]ite simulator.‖ 

Even if we agreed that these steps constituted the commencement of a lawful 

process, we would nonetheless find the second element of the inevitable-discovery 

test—the ―requisite actuality‖ that the process would have led to the discovery of 

Mr. Jones—lacking. This is because the police either suspended or abandoned the

purported lawful process when they chose to deploy the only operational cell-site 

simulator in their possession on Mr. Jones‘s phone. 

This court has found the inevitable-discovery doctrine applicable in cases in 

which the police engaged in lawful and unlawful processes in parallel. See 

Pinkney v. United States, 851 A.2d 479, 495 (D.C. 2004); McFerguson v. United 

States, 770 A.2d 66, 74–75 (D.C. 2001); Hicks, 730 A.2d at 662. Had the unlawful 

process not occurred in these cases, the lawful one would inevitably have produced 

the same evidentiary result. But here the government is asking us to find inevitable 

discovery where the police had mutually exclusive options and, for whatever 
30

reason, chose the option that turned out to be unlawful. The inevitable-discovery

doctrine does not apply in this type of situation. See Gore, 145 A.3d at 549 n.32

(―[T]he argument that  ̳if we hadn't done it wrong, we would have done it right‘ is 

far from compelling.‖ (quoting 6 LaFave, supra, § 11.4 (a)) (internal quotation 

marks omitted)).

32

 

 

32

 Unlike our dissenting colleague, we are not persuaded by the 

government‘s alternative argument that because Mr. Jones was carrying the stolen 

phones, which could have been located and tracked lawfully (it is assumed), Mr. 

Jones had no expectation of privacy in his location. This argument was not raised 

in the initial briefing or in the trial court—it was first raised at oral argument 

before this court in response to questions from the bench. Although after oral 

argument we requested supplemental briefing on this argument, we ultimately 

conclude that the government‘s failure to present it at an earlier stage constitutes a 

waiver of the argument under the circumstances of this case. See Tuckson v. 

United States, 77 A.3d 357, 366 (D.C. 2013); Rose v. United States, 629 A.2d 526, 

535 (D.C. 1993); see also Greenlaw v. United States, 554 U.S. 237, 244 (2008) 

(―We wait for cases to come to us, and when they do we normally decide only 

questions presented by the parties. Counsel almost always know a great deal more 

about their cases than we do, and this must be particularly true of counsel for the 

United States, the richest, most powerful, and best represented litigant to appear 

before us.‖ (quoting United States v. Samuels, 808 F.2d 1298, 1301 (8th Cir. 

1987) (Arnold, J., concurring in denial of rehearing en banc))). In any case, the 

argument is unpersuasive because, as we have explained above, ―[t]he fact that 

equivalent information could sometimes be obtained by other means does not make 

lawful the use of means that violate the Fourth Amendment.‖ Kyllo, 533 U.S. at 35 

n.2; see also Maynard, 615 F.3d at 566. And as amici have cogently argued in 

their supplemental submission, ―[c]onsidering as part of the reasonableexpectation-of-privacy inquiry the availability of alternative means to gather 

information would collapse inevitable discovery into the reasonable-expectation 

question in a manner that would radically transform both doctrines.‖ As amici 

explain, were we to adopt the government‘s—and the dissent‘s—novel theory of

(continued...)
31

 C. Good-Faith Exception

We turn next to the government‘s argument that application of the 

exclusionary rule here ―would not meaningfully deter police misconduct‖ because 

the use of the cell-site simulator to locate Mr. Jones was ―not the type of  ̳flagrant‘ 

abuse for which the exclusionary rule was designed.‖ In support of this argument, 

the government notes that Sergeant Perkins and his team believed ―exigent 

circumstances existed‖ and asserts that ―at the time of this incident, no court had 

held that using a simulator to locate a phone violates the Fourth Amendment.‖ The 

government further points out that the police received judicial approval for various 

secondary searches of the evidence recovered from Mr. Jones and Ms. Williams at 

the time of Mr. Jones‘s arrest. Specifically, the police obtained warrants to search 

Mr. Jones‘s Saturn and the phones they recovered from Mr. Jones and Ms. 

Williams, and secured a court order to take a buccal swab from Mr. Jones. 

Although it does not explicitly say so, the government is invoking the 

 

(...continued)

affirmance, ―the contours of the inevitable discovery doctrine, a carefully crafted 

exception to the exclusionary rule with strict requirements, would be subject to 

end-runs, because the possibility of an alternative means of discovery could often 

be repackaged as a reason to reject an expectation of privacy in the first place‖ 

(citation omitted). 
32

―good-faith exception.‖ Davis v. United States, 564 U.S. 229, 239 (2011). The 

Supreme Court first recognized this exception in United States v. Leon, 468 U.S. 

897 (1984), holding that ―evidence obtained [by the police] in objectively 

reasonable reliance on a subsequently invalidated search warrant‖ is not subject to 

the exclusionary rule. Id. at 922. This holding was based on the premise that ―the 

deterrence rationale [for exclusion] loses much of its force‖ ―when the police act 

with an objectively reasonable good-faith belief that their conduct is lawful.‖ 

Davis, 564 U.S. at 252; id. at 238 (quoting Leon, 468 U.S. at 909, 919) (internal 

quotation marks omitted). The Court has since extended the good-faith exception 

to apply in various other situations involving nonculpable or merely negligent lawenforcement conduct. See, e.g., id. at 239–40 (holding that the good-faith 

exception applies ―when the police conduct a search in objectively reasonable 

reliance on binding judicial precedent‖); Herring, 555 U.S. at 136 (holding that the 

good-faith exception applied to evidence obtained in a search incident to arrest 

where the officer ―reasonably believe[d] there [wa]s an outstanding arrest warrant‖ 

for the defendant, but where ―that belief turn[ed] out to be wrong because of a 

negligent bookkeeping error by another police employee‖).

The Supreme Court has not, however, recognized the applicability of the 

good-faith exception in a situation remotely like the present one—where the 
33

police, not acting pursuant to a seemingly valid warrant, statute, or court opinion, 

conducted an unlawful search using a secret technology that they had shielded 

from judicial oversight and public scrutiny. See supra note 26. Indeed, assuming 

the police believed the warrantless use of the cell-site simulator to be lawful, they 

could not have reasonably relied on that belief, given the secrecy surrounding the 

device and the lack of law on the issue.

33

 And the government does not argue that 

the police officers‘ mistaken belief that exigent circumstances existed was 

reasonable or cite any case law that would support such an argument. 

The fact that some of the evidence was obtained in secondary searches 

pursuant to warrants and a court order does not change things. The police‘s 

reliance on the warrants and order was not objectively reasonable because the 

warrants and order were based on information obtained in violation of Mr. Jones‘s 

Fourth Amendment rights. See Evans v. United States, 122 A.3d 876, 886 (D.C. 

2015) (―The subsequent issuance of [a] search warrant . . . , based on information 

[illegally] obtained . . . , d[oes] not operate to attenuate the [original] illegality.‖).34 

 

33

 The Supreme Court has implicitly foreclosed the government‘s argument 

that police can reasonably conclude from the complete lack of judicial precedent 

that their conduct is lawful. See Davis, 564 U.S. at 248 (suggesting that the goodfaith exception for police reliance on binding judicial precedent would not apply 

where ―the precedent is distinguishable‖). 

34

 The government cites United States v. McClain, 444 F.3d 556 (6th Cir. 

(continued...)
34

Thus, the evidence the police obtained through their warrantless use of the cell-site 

simulator is not subject to the good-faith exception.

D. Change in Department of Justice Policy

The government‘s final argument for not applying the exclusionary rule is 

that a change in Department of Justice (DOJ) policy has diminished the likelihood 

that excluding the evidence in this case will deter misconduct in the future. The 

government asserts that the MPD is bound by a new DOJ policy to ―obtain a search 

warrant supported by probable cause‖ before deploying a cell-site simulator. Dep‘t 

of Justice Policy Guidance: Use of Cell-Site Simulator Technology at 3–4 (Sept. 

3, 2015), https://www.justice.gov/opa/file/767321/download. 

 

(...continued)

2006), in which the court declined to apply the exclusionary rule where officers 

conducted a search pursuant to a warrant based in large part on information that 

had been illegally gathered. This court‘s holding in Evans precludes us from 

following McClain. And in any case, McClain is distinguishable because there the 

―warrant affidavit fully disclosed to a neutral and detached magistrate the 

circumstances surrounding the initial [illegal] search.‖ Id. at 566. Here, by 

contrast, the police did not disclose in their applications for the warrants and order 

that they had deployed a cell-site simulator to locate Mr. Jones. Indeed, in the 

otherwise lengthy affidavit for the warrants, the officers‘ search for Mr. Jones is 

described in a single sentence: ―[T]he Defendant was located by members of the 

Washington, D.C. Metropolitan Police Department . . . .‖ The government cannot 

rely on the Leon good-faith exception when the police have not been ―frank with 

the magistrate in proceedings to obtain the warrant.‖ United States v. Reilly, 76 

F.3d 1271, 1273 (2d Cir.), on reh’g, 91 F.3d 331 (2d Cir. 1996).
35

The government did not develop this argument in the trial court—and could 

not have, as the DOJ policy had not yet been issued—and we do not find it 

persuasive. The government has not cited any case in which a court has declined 

to apply the exclusionary rule based on the government‘s representation that it will 

not engage in unlawful conduct in the future. The government cites Blair v. United 

States, 114 A.3d 960 (D.C. 2015), but in that case we relied on a change in a 

statute that eliminated the need to deter subsequent violations, not a mere change 

in policy. Id. at 973–74. And given that the DOJ policy memorandum does not 

describe any sort of enforcement mechanism that would ensure compliance with 

the policy, and given that the present administration or a subsequent one may well

revise this policy, we are not convinced that the need to deter future constitutional 

violations is lacking.

 E. Fruit of the Poisonous Tree

Having decided that the exclusionary rule applies in this case, we must now 

decide which evidence should be excluded as ―fruit of the poisonous tree‖ of the 

illegal search.

35

 Wong Sun, 371 U.S. at 488. In deciding whether evidence 

 

35

 In the trial court, Mr. Jones specifically moved to ―[s]uppress 

[i]dentifications, [s]tatements, and [t]angible evidence‖ resulting from the illegal 

search. The evidence and testimony that Mr. Jones identifies as fruits of the 

(continued...)
36

constitutes fruit of the poisonous tree, the critical inquiry is whether ―the evidence 

. . . has been come at by exploitation of th[e] illegality or instead by means 

sufficiently distinguishable to be purged of the primary taint.‖ Wong Sun, 371 U.S. 

at 488 (quoting John Maguire, Evidence of Guilt 221 (1959)); see also Wilson v. 

United States, 102 A.3d 751, 753 (D.C. 2014). The court considers ―[t]he temporal 

proximity of the [illegality] and the [acquisition of the evidence], the presence of 

intervening circumstances, and, particularly, the purpose and flagrancy of the 

official misconduct.‖ Brown v. Illinois, 422 U.S. 590, 603–04 (1975) (citations 

and footnote omitted); see also Gordon v. United States, 120 A.3d 73, 85 (D.C. 

2015).

Mr. Jones argues that the following evidence and testimony should have 

been excluded as fruits of the poisonous tree: his knife, a statement he made to the 

 

(...continued)

poisonous tree in this appeal clearly fall within these categories, and the 

government could not have reasonably doubted that Mr. Jones intended to have 

them suppressed. The government had a ―full and fair opportunity‖ in the trial 

court to litigate this matter. Barnett v. United States, 525 A.2d 197, 200 (D.C. 

1987). And the record before us is ―of amply sufficient detail and depth‖ to permit 

us to decide the scope of the exclusionary rule as a matter of law. Brown v. 

Illinois, 422 U.S. 590, 604 (1975). We thus (except as to the testimony of Ms. 

Williams, see infra note 41) decline the government‘s request that we remand the 

case so that the trial court can ―hold hearings, make factual findings of fact, and 

reach legal conclusions on the application of the fruit-of-the-poisonous-tree 

doctrine.‖ 
37

police at the scene of his arrest, cellphones recovered from Ms. Williams‘s purse at 

the scene of the arrest, evidence (including cellphones) recovered from his car (the 

Saturn) pursuant to a warrant, data extracted from the various cellphones pursuant 

to warrants, the testimony of Ms. Williams, the later photo-array identification of 

Mr. Jones by one of the complainants, a DNA profile generated from a buccal 

swab of Mr. Jones (a month after his arrest), and a photograph of Mr. Jones‘s 

groin.36 The government ―agrees that some, but not all, of the . . . evidence 

[identified by Mr. Jones] is a fruit of the alleged poisonous tree.‖ The government

only specifically objects to classifying (1) Mr. Jones‘s statement to the police, (2) 

the cellphones recovered from Ms. Williams‘s purse, and (3) Ms. Williams‘s 

testimony as fruits of the poisonous tree.

1. Prince Jones’s Statement

Mr. Jones made an incriminating statement to the police at the scene of the 

arrest: When asked what his address was, Mr. Jones gave the address of one of the 

sexual-assault complainants. The government argues that this statement should not 

be suppressed as a fruit of the unlawful cell-site-simulator search because ―[i]t 

 

36

 One of the complainants testified at trial about the appearance of Mr. 

Jones‘s genital area, and the photograph of Mr. Jones‘s groin was admitted in 

evidence at trial. 
38

would make little sense to suppress evidence obtained merely as part of a routine 

booking procedure.‖ See Thomas v. United States, 731 A.2d 415, 421 (D.C. 1999)

(recognizing ―a routine booking question exception‖ to the rule of Miranda v. 

Arizona, 384 U.S. 436 (1966)). We reject this argument. That the question about 

Mr. Jones‘s address was otherwise proper does not negate the fact that very little 

time and no substantial intervening circumstances separated the illegal search from 

Mr. Jones‘s incriminating response. See United States v. Olivares-Rangel, 458 

F.3d 1104, 1112 (10th Cir. 2006). Mr. Jones‘s statement was a direct product of 

the unlawful search and is thus excludable as fruit of the poisonous tree.

2. Cellphones from Nora Williams’s Purse

When the police located Mr. Jones and Ms. Williams, they searched Ms. 

Williams‘s purse and found several cellphones, including two of the complainants‘ 

phones and Mr. Jones‘s phone. The government argues that the contents of Ms. 

Williams‘s purse are not fruits of the poisonous tree because Mr. Jones did ―not 

have a reasonable expectation of privacy in the contents of Ms. Williams‘s purse‖ 

and because ―Ms. Williams gave the officers consent to search her purse.‖ 

Preliminarily, Mr. Jones‘s expectation of privacy (or lack thereof) in Ms. 

Williams‘s purse is not a material consideration in the fruit-of-the-poisonous-tree 
39

analysis. As one court has explained, ―[w]hile the fruit of the poisonous tree 

doctrine applies only when the defendant has standing regarding the Fourth 

Amendment violation which constitutes the poisonous tree, the law imposes no 

separate standing requirement regarding the evidence which constitutes the fruit of 

that poisonous tree.‖37 Olivares-Rangel, 458 F.3d at 1117 (citation omitted); see 

also 6 LaFave, supra, § 11.4 (―If the defendant [has] standing with respect to the 

poisonous tree, that alone suffices . . . .‖).

The factors in Brown, 422 U.S. at 604, moreover, compel a conclusion that 

the contents of Ms. Williams‘s purse are fruits of the poisonous tree. First, as the 

search of Ms. Williams‘s purse occurred at the scene of Mr. Jones‘s apprehension 

and arrest, very little time passed between the police‘s unlawful cell-site-simulator 

search and their recovery of the evidence from Ms. Williams‘s purse. 

 

37

 United States v. Bowley, 435 F.3d 426, 430–31 (3d Cir. 2006), and United 

States v. Pineda-Chinchilla, 712 F.2d 942, 943–44 (5th Cir. 1983), cited by the 

government, stand only for the narrow proposition that a defendant cannot 

suppress the contents of his immigration file even if the prosecuting authority‘s 

discovery of that file or its connection to the defendant was based on evidence 

gathered in an illegal search or seizure. Thus, even if we were to find these cases 

persuasive, but see 6 LaFave, supra, § 11.4 & n.22, they would not support the 

proposition that a defendant must always—or even usually—have standing in a 

particular item of evidence to have it suppressed as a fruit of an illegal search or 

seizure.
40

Second, Ms. Williams‘s supposed consent was not a significant intervening 

circumstance. According to Detective Pulliam, Ms. Williams consented only after 

the police presented her with the following options: the police ―would either have 

to take the purse and put it into police custody until [they] could get a search 

warrant and then search it or . . . she could give [the police] consent to search it.‖ 

Given this threat and the fact that her boyfriend, Mr. Jones, had just been arrested 

in her presence, Ms. Williams‘s consent was not sufficiently ―the product of free 

will [to] break . . . the causal connection between the illegality and the‖ search of 

the purse. Brown, 422 U.S. at 603; cf. Utah v. Strieff, 136 S. Ct. 2056, 2062 (2016) 

(holding that a valid arrest warrant ―entirely unconnected with the [illegal] stop‖ 

was a sufficient intervening circumstance); 4 LaFave, supra, § 8.2 (c) (explaining 

that a person‘s consent to a search may be involuntary where the police, ― ̳trading 

on‘ a prior Fourth Amendment violation,‖ have ―threat[ened] to seek a warrant‖).38 

And third, although the police officers‘ warrantless use of the cell-site 

 

38

 The proper inquiry here is not whether Ms. Williams‘s consent was a 

valid waiver of her own rights, but rather whether it constituted an intervening 

circumstance sufficient to purge the taint of the illegal search. Thus, we need not 

decide whether Ms. Williams could have had the evidence excluded had she 

herself been tried. See generally 4 LaFave, supra, § 8.2 (c) (discussing Fourth 

Amendment cases in which ―the police have obtained consent to search after 

threatening that if consent were not given they would proceed to seek or obtain a 

search warrant‖).
41

simulator here was not flagrant misconduct,

39 recovery of Mr. Jones‘s cellphone 

and the complainants‘ phones was undoubtedly one of the officers‘ purposes in 

deploying the cell-site simulator. The cell-site simulator is used to locate and track 

phones after all. The contents of Ms. Williams‘s purse thus ―bear a . . . close 

relationship to the underlying illegality.‖ Gordon, 120 A.3d at 85 (quoting New 

York v. Harris, 495 U.S. 14, 19 (1990)).40

3. Nora Williams’s Testimony41

Mr. Jones argues that Ms. Williams should have been barred from testifying 

 

39

 But see supra text accompanying note 33.

40

 The government contends that even if the cellphones in Ms. Williams‘s 

purse are fruits of the poisonous tree, the ―call detail records and location 

information obtained from the provider‖ for the cellphones ―are not subject to 

exclusion.‖ Mr. Jones has not argued otherwise, and we see no reason for 

classifying this information as fruit of the poisonous tree.

The government also represents in its brief that ―the government received an 

unsolicited offender hit from the FBI‘s Combined DNA Index System ( ̳CODIS‘) 

indicating that a sample obtained from [Mr. Jones] in connection with [a] prior 

Maryland conviction matches the crime scene sample obtained in this case.‖ 

Assuming that the government can demonstrate this in the trial court, we agree 

with the government that it ―should not be precluded from seeking another buccal 

swab [from Mr. Jones] based on the independent and untainted CODIS hit.‖ This 

CODIS hit would not be a fruit of the illegal search.

41

 This part does not constitute the opinion of the court, as it is not joined by 

Associate Judge THOMPSON or Senior Judge FARRELL.
42

for the government at trial. The government disagrees, arguing that ―[t]here was 

sufficient attenuation between the search and Ms. Williams‘s testimony to dissipate 

any taint‖ and that ―the government would have inevitably discovered Ms. 

Williams through independent sources.‖ 

In United States v. Ceccolini, 435 U.S. 268 (1978), the Supreme Court 

recognized factors pertinent to the determination of whether a witness‘s testimony 

should be barred as fruit of the poisonous tree: (1) whether ―the testimony given by 

the witness was an act of her own free will in no way coerced,‖ (2) whether 

evidence gathered or information learned as a result of the illegal search was used 

to question the witness, (3) whether ―[s]ubstantial periods of time elapsed between 

the time of the illegal search and the initial contact with the witness . . . and 

between the [initial contact] and the testimony at trial,‖ (4) whether the witness and 

―her relationship with the [defendant] were well known‖ to the police before the 

illegal search, and (5) whether the officers conducting the illegal search did so with 

the ―intent of finding a willing and knowledgeable witness to testify against‖ the 

defendant. Id. at 279–80; see also 6 LaFave, supra, § 11.4 (i). These factors 

weigh in favor of excluding Ms. Williams‘s testimony.

First, it is undisputed that Ms. Williams was not a willing witness for the 

government. As the government points out, Ms. Williams was initially ―not 
43

forthcoming about her knowledge and use of the . . . items‖ stolen from the 

complainants, and only testified after ―the government sought and received a court 

order granting her immunity.‖ Ms. Williams testified at trial that after she was 

granted immunity, she testified for the grand jury ―[b]ecause [she] had no choice.‖ 

She expressed unhappiness about having to testify against Mr. Jones at trial, stating 

that she ―didn‘t want to go against him.‖ 

Second, the government admits that the police ―confronted [Ms. Williams] 

with the fact that stolen phones and other items were recovered from her purse and 

from the car.‖ This evidence, as explained above, was the product of the illegal 

search. The government‘s attempt to minimize the significance of this fact is 

unpersuasive. The government contends that the ―illegally obtained evidence 

ultimately did not play a great role in obtaining Ms. Williams‘s testimony‖ and that 

it was the grant of immunity that was the decisive factor. But this argument fails to 

address the fact that the police questioned Ms. Williams before she was 

immunized, and is also speculative: It is plausible—indeed, likely—that both the 

grant of immunity and fact that Ms. Williams was found red-handed with the 

proceeds of the robberies played significant roles in her decision to testify. 

Third, a very short period of time passed between the illegal search and Ms. 

Williams‘s first contact with the police. Indeed, Ms. Williams was present at Mr. 
44

Jones‘s arrest and was questioned at the scene. See United States v. RamirezSandoval, 872 F.2d 1392, 1397 (9th Cir. 1989). Approximately a year passed 

between the police‘s initial contact with Ms. Williams and her testimony at trial, 

but a lengthy period between first contact and trial is almost always present in a 

criminal case, and this time period is less significant than the time period between 

the search and first contact. Moreover, the witness‘s initial statements to the police 

will often significantly constrain the witness‘s testimony at trial because the initial 

statements can be used to impeach the witness or bolster his or her testimony. See 

1 Kenneth S. Broun et al., McCormick on Evidence § 34 (7th ed. 2016) (discussing 

the procedure of impeaching a witness with a prior inconsistent statement); id. § 47 

(discussing the procedure of supporting a witness with a prior consistent 

statement). 

Fourth, although at trial the government offered in evidence surveillance 

footage of Ms. Williams using an ATM card stolen from one of the complainants,

at the suppression hearing the government neither presented evidence nor argued 

that the police had this video before they conducted the illegal cell-site-simulator 

search or that the video would have enabled the police to locate Ms. Williams. 

Thus, based on the record before the court, it is not possible to conclude that the 

police were aware of Ms. Williams or her relationship with Mr. Jones before they 
45

located her through the illegal search. See also supra note 35. 

The remaining factor favors the government. Specifically, there is no reason 

to believe that the police intended their use of the cell-site simulator to result in the 

discovery of a witness for the government. Rather, the record before the court 

suggests that the police were trying to locate Mr. Jones—and, as a necessary 

consequence of their use of cellphone tracking, Mr. Jones‘s cellphone. 

Nonetheless, because the other four factors strongly weigh in favor of suppression, 

there is ―a close[], . . . direct link between the illegality and [Ms. Williams‘s]

testimony.‖ Ceccolini, 435 U.S. at 278.

F. Harmless-Error Analysis

The introduction of evidence collected in violation of Mr. Jones‘s Fourth 

Amendment right to be free from unreasonable searches and seizures is 

constitutional error. So we must reverse Mr. Jones‘s convictions unless the 

government has ―prove[d] beyond a reasonable doubt that the error . . . did not 

contribute to the verdict.‖ Chapman v. California, 386 U.S. 18, 24 (1967). 

Because we have concluded that the fruits identified by Mr. Jones should have 
46

been excluded at his trial,42 and because these fruits comprised some of the most 

damning evidence against him, we need not undertake a detailed analysis to 

conclude that the erroneous admission of these fruits at trial was not harmless 

beyond a reasonable doubt. The government does not argue otherwise. 

III. Conclusion

For the foregoing reasons, we reverse the judgment of the trial court and 

remand for further proceedings consistent with this opinion.

 

42

 To be entirely accurate, we have reached this conclusion with respect to 

all of the purported fruits except for the testimony of Ms. Williams. See supra

note 41. The conclusion that the error was not harmless beyond a reasonable doubt 

nonetheless stands.
47

FARRELL, Senior Judge, concurring in part and concurring in the judgment: 

I agree with Judge Beckwith that the police‘ use of the cell-site simulator to 

discover appellant‘s precise location violated the Fourth Amendment because it 

was a ―search‖ requiring a warrant. My analysis of why that is so is more limited 

than Judge Beckwith‘s, however. I also agree that the government has not shown 

that the fruits of the use of the simulator would have been inevitably discovered by 

lawful means, and that this is not the sort of case in which the Supreme Court has 

found that suppression of the fruits would serve no deterrent purpose. Further, 

except that I would not decide whether the testimony of Nora Williams should 

have been suppressed, I agree that the evidence discussed in part II. E. of Judge 

Beckwith‘s opinion was suppressible fruit of the warrantless search. Finally, I 

explain briefly why I am not persuaded by Judge Thompson‘s position in dissent 

that no search at all under the Fourth Amendment took place.

I.

As to inevitable discovery, a key argument by appellee in its original brief, I 

agree that the government has failed to show the ―requisite actuality,‖ Hicks v. 

United States, 730 A.2d 657, 659 (D.C. 1999), that tracking the complainants‘ 

cellphones with the simulator, had that taken place, would have led to the same 

seizure of incriminating evidence. The government in its brief states that 
48

appellant‘s and the complainants‘ cellphones ―were ultimately found together in 

appellant‘s car,‖ and that since ―the simulator was close enough to locate one of 

the phones, it inevitably was close enough to locate the other‖ (Appellee‘s Brief at 

32). But this analysis is troublesome partly because it relies on the fruits of the 

actual simulator use. See 6 WAYNE R. LAFAVE, Search and Seizure: A Treatise on 

the Fourth Amendment § 11.4 (a), at 283 (5th ed. 2016) (― ̳[T]he fact making 

discovery inevitable must arise from circumstances other than those disclosed by 

the illegal search itself.‘‖). Moreover, the police began using the simulator a 

considerable length of time after appellant had come into possession of the 

complainants‘ cellphones, and even then some 30–45 minutes elapsed before the 

simulator directed them to appellant‘s car and cellphone. So there is too much 

surmise, I submit, in the reasoning that if the police had used the simulator to 

locate the complainants‘ phones instead, those phones would still have been in 

appellant‘s possession or, if so, in a powered-on condition enabling their detection.

II.

The dispositive issue, then, is whether the use of the cell-site simulator was a 

―search‖ requiring the police to have obtained a warrant beforehand (in the nowconceded absence of exigent circumstances). To answer that question it is enough, 

I believe, to know how the simulator learns of a target cellphone‘s location. It does 
49

so by effectively commandeering the cellphone as a police investigative tool in the 

way Judge Beckwith describes, namely, by ―actively induc[ing] the phone to 

divulge its identifying information,‖ ante at 17, from which the phone‘s direction 

and distance relative to the simulator can be determined. This process of 

―grabbing‖ the target phone and making it the instrument of its own locational 

disclosure explains why the government‘s primary reliance on the third-party 

doctrine of Smith v. Maryland, 442 U.S. 735 (1979)—―Smith . . . is controlling 

here‖ (Appellee‘s Brief at 23)—to argue that appellant had no reasonable 

expectation of privacy in the police‘ use of his phone is unpersuasive.

Smith held that an individual enjoys no Fourth Amendment protection ―in 

information he voluntarily turns over to [a] third part[y].‖ Id. at 743–44. The 

reason is that by ―revealing his affairs to another‖ an individual ―takes the risk . . . 

that the information will be conveyed by that person to the government.‖ United 

States v. Miller, 425 U.S. 435, 443 (1976). Recently the Fourth Circuit applied the 

third-party doctrine to hold that the government‘s acquisition of historical cell-site 

location information (CSLI) from a suspect‘s cellphone provider is not a search 

under the Fourth Amendment. United States v. Graham, 824 F.3d 421 (4th Cir. 

2016) (en banc). Although that issue remains an open one in this court, and the 

Supreme Court is expected to decide it this term, Carpenter v. United States, No. 
50

16-402, cert. granted June 5, 2017, Graham‘s analysis at least serves by 

comparison to show why the use of a cell-site simulator to locate appellant‘s phone 

compels a different conclusion.1

Graham distinguished prior Supreme Court cases involving ―direct 

government surveillance‖ (e.g., United States v. Karo, 468 U.S. 705 (1984); United 

States v. Jones, 565 U.S. 400 (2012)) from the situation where the government 

―obtains, from a third party, the third party‘s records, which permit the government 

to deduce location information.‖ 824 F.3d at 426. Because CSLI is information 

the individual has already ― ̳exposed‘ . . . to the phone company‘s  ̳equipment in 

the ordinary course of business,‘‖ that person has ― ̳assumed the risk‘ that the 

phone company would disclose their information to the government.‖ Id. at 427-

28 (quoting Smith, 442 U.S. at 744). The government thus ―does not engage in a 

Fourth Amendment  ̳search‘ when it acquires‖ CSLI from the cellphone provider. 

Id. at 427. But in contrast to this passive ―acquir[ing]‖ or ―obtain[ing]‖ of CSLI, 

direct government surveillance of a cellphone does constitute a search, as when —

the Fourth Circuit observed by footnote — ―the government uses cell-site 

 

1

 The fact that the Supreme Court will take up cell phone technology in 

relation to the Fourth Amendment is alone reason for us to decide the present issue 

narrowly and not opine in broad stokes about privacy and electronic information, 

locational or other.
51

simulators . . . to directly intercept CSLI instead of obtaining CSLI records from 

phone companies.‖ Id. at 426 n.4

When the police seek and obtain locational information by directly 

interacting with, indeed by taking functional control of, a suspect‘s cellphone 

through a simulator, it cannot reasonably be said that the phone user has 

―voluntarily conveyed‖ locational information to anyone and thereby relinquished 

a reasonable expectation of privacy in the information. Smith, 442 U.S. at 744. 

Police requests for cellphone location data held by a third party, however the 

Supreme Court resolves that privacy issue, are not comparable to forcing a 

cellphone to disclose its own identifying data. The police located appellant‘s 

phone by effectively making it a self-investigative tool. Any reduced expectation 

of privacy an individual accepts by entering the cellphone world does not extend to 

co-optation of that kind.

III.

I also agree that suppression of most of the fruits of the unlawful search here 

will ―pay its way,‖ United States v. Leon, 468 U.S. 897, 919 (1984), under the 

―cost-benefit analysis in exclusion cases.‖ Davis v. United States, 564 U.S. 229, 

238 (2011). As Judge Beckwith points out, the government has not sought to show 
52

that any belief the police had that there was no time to pursue a search warrant was 

objectively reasonable, albeit mistaken. The record suggests, to the contrary, that 

the police decided to forgo the warrant process either believing — unreasonably, in 

the virtual absence of relevant court decisions—that no Fourth Amendment 

intrusion was involved or to honor a proprietary agreement for secrecy in using the 

device. See ante at 22 n.26. Thus, the search cannot be said to have involved the 

sort of ― ̳isolated,‘  ̳nonrecurring‘ police negligence . . . [that] lacks the culpability‖ 

required to justify suppression, Davis, 564 U.S. at 239 (citing Herring v. United 

States, 555 U.S. 135, 137 (2009)), even if it entailed no ― ̳deliberate,‘  ̳reckless,‘ or 

 ̳grossly negligent‘ disregard for Fourth Amendment rights.‖ Davis, 564 U.S. at 

238. The unlawfulness here was not like the ―err[or] in maintaining records in a 

warrant database,‖ id. at 239, involved in both Arizona v. Evans, 514 U.S. 1 

(1955), Herring, supra; nor was it comparable to the mistaken but ―objectively 

reasonable reliance on binding judicial precedent‖ in Davis, 564 at 239.

Exclusion of evidence was thus a proper remedy here, except that, unlike 

Judge Beckwith, I would not decide whether the testimony of Nora Williams 

should have been suppressed. Her testimony was given more than a year after the 

illegal search and only after, now represented by counsel, she had received use 

immunity for her testimony. Those circumstances present a difficult question of 
53

attenuation that we need not reach, because the admission of the immediate fruits 

of the search was not harmless error and requires reversal. In any new trial the 

parties can brief and the trial court resolve the issue of the admissibility of 

Williams‘ testimony, should the issue arise.

Finally, I am not persuaded by Judge Thompson‘s position in dissent that no 

Fourth Amendment search took place because appellant had no ―reasonable 

expectation that the location of his cell phone would remain private while he was 

traveling on the public roads with a powered-on, stolen cell phone.‖ Post at 68 

(emphasis added). That contention, resting on appellant‘s presumed awareness of 

how the police might have located him (via the stolen cell phone) but did not, 

closely resembles the inevitable discovery argument we have rejected. See

Appellee‘s Supp. Brief at 6 (―[A]ppellant has effectively conceded that the use of a 

cell site simulator to locate the stolen Sprint cell phone would have been a  ̳lawful 

investigative process‘‖ (emphasis added)). Moreover, the theory appears to 

assume a conclusion of wrongdoing—that appellant possessed a ―stolen‖ phone—

disputed by appellant‘s not-guilty plea at the time the suppression motion was 

litigated.2 It would be unfair to hold that, in moving to suppress the fruits of the 

 

2

 In McFerguson v. United States, 770 A.2d 66 (D.C. 2001), this court 

rejected the argument that ―society would [not] impute a reasonable expectation of 

(continued...)
54

search of his cell phone, appellant assumed the burden of proving that his 

possession of another‘s phone was lawful—the issue of guilty possession vel non

on which the government would have the burden of proof at trial. The dissent‘s 

ingenious argument for why no search took place is too fraught with difficulty to 

provide a basis for admitting in evidence the fruits of the warrantless manipulation 

of appellant‘s cell phone.

THOMPSON, Associate Judge, dissenting: My colleagues in the majority are 

―properly and commendably concerned about the threats to privacy that may flow 

from advances in the technology available to the law enforcement profession.‖1 I 

share their concern, but I am not persuaded to their conclusion in this case, which I 

believe rests on a too-generic description of the facts surrounding use of the cellsite simulator involved here. My colleagues express concern that ―[a] cell-site 

simulator allows police officers who possess a person‘s telephone number to 

discover that person‘s precise location remotely and at will.‖ Ante at 17. But this 

 

(...continued)

privacy to a burglar running away from the crime scene carrying in plain view a 

distinctively marked shopping bag . . . stolen from the burgled residence and filled 

with the victim‘s property.‖ Id. at 71 (internal quotation marks and ellipses 

omitted). The government‘s argument, we said, ―assumes the very facts that were 

to be proved at trial — that [the defendant] was fleeing with goods he had stolen in 

the burglary.‖ Id.

1

 Kyllo v. United States, 533 U.S. 27, 51 (2001) (Stevens, J., dissenting).
55

case is about far more particular and narrow facts, and here, as always, Fourth 

Amendment analysis must be ―extremely fact-specific‖;2―[i]t is important to be 

clear about what occurred in this case[.]‖3 

Described with the necessary specificity, this case is about the following: 

Police had near real-time cell-site location information from cell phone providers4

that a cell phone, which police knew (from a review of victim call records) had 

been used by the perpetrator of two recent sexual assaults and related robberies to 

lure his victims, was traveling on the public streets together with a powered-on

5

Sprint cell phone (the ―stolen phone‖) that the perpetrator had stolen from one of 

the robbery victims, and was in the vicinity of the Minnesota Avenue Metro 

 

2

 In re Application of United States for Historical Cell Site Data, 724 F.3d 

600, 603 (5th Cir. 2013) (internal quotation marks omitted).

3

 United States v. Jones, 565 U.S. 400, 404 (2012).

4

 As the majority opinion notes, ante at 16 n.20, appellant has not argued in 

this appeal that his Fourth Amendment rights were violated when the government 

obtained cell-site location information from cellular providers. See United States 

v. Graham, 824 F.3d 421, 428 (4th Cir. 2016) (joining other circuit courts in 

holding that ―individuals do not have a reasonable expectation of privacy in 

historical [cell-site location information] that the government obtains from cell 

phone service providers‖).

5

 Police Technical Services Unit (―TSU‖) Sergeant Perkins testified at the 

suppression hearing in this case that, as long as it‘s ―powered on,‖ a cell phone ―is 

constantly transmitting to and receiving from a tower.‖ 
56

station; and, after driving to the area near that station, law enforcement officers 

using a cell-site simulator (over a period of 30 to 45 minutes) were led to a row of 

cars parked on the street near the Metro station and thence to the sole occupied car, 

in which appellant sat with the stolen cell phone in his possession.6 

I can agree with my colleagues that ―under ordinary circumstances,‖ ante at

20, the government‘s use of a cell-site simulator to locate an individual through the 

individual‘s cellphone likely violates the legitimate expectation of privacy we all 

have in our location information.7 I would also agree that ―individuals have a 

reasonable expectation of privacy in their location information when they are 

tracked in a space, like the home, that is traditionally protected or when they are 

tracked for a longer period of time and in greater detail than society would expect.‖ 

Historical Cell Site Data, 724 F.3d at 608 (describing a contention by the ACLU). 

But I do not believe it is fair to regard the particular circumstances of this case, 

which I have described above, as ―ordinary circumstances.‖ And as the facts of 

 

6

 Actually, at the time appellant was arrested, he had in his car all four 

stolen cell phones involved in this case. 

7

 I acknowledge that some courts have so held. See, e.g., United States v. 

Ellis, No. 13-CR-00818 PJH, 2017 U.S. Dist. LEXIS 136217, *20 (N.D. Cal. Aug. 

24, 2017) (―[C]ell phone users have an expectation of privacy in their cell phone 

location in real time and . . . society is prepared to recognize that expectation as 

reasonable.‖).
57

this case (1) do not involve the privacy of the home;8(2) did not entail long-term

tracking that could reveal appellant‘s private information about the places he 

frequents;9(3) did not entail a physical intrusion or a physical trespass to any 

 

8

 That fact distinguishes this case from cell-site simulator cases on which 

appellant relies. See State v. Andrews, 134 A.3d 324 (Md. Ct. Spec. App. 2016), 

and United States v. Lambis, 197 F. Supp. 3d 606, 609 (S.D.N.Y. 2016). In 

Andrews, police used a cell-site simulator to locate Andrews, who was wanted on 

charges of attempted murder, and tracked him to a location inside a residence, 

where he was arrested. 134 A.3d at 326. The court cited its concern that the cellsite simulator had ―been used to obtain information about the contents of a home, 

not otherwise discernable without physical intrusion.‖ Id. at 349. The court stated 

that ―people have a reasonable expectation that their cell phones will not be used as 

real-time tracking devices by law enforcement‖ and ―an objectively reasonable 

expectation of privacy in real-time cell phone location information.‖ Id. at 327. In 

Lambis, the Drug Enforcement Administration used a cell-site simulator to locate 

Lambis‘s apartment, conduct that the court found to be an unreasonable search 

because ―[t]he home has special significance under the Fourth Amendment.‖ 197 

F. Supp. 3d at 609–10. These cases are consistent with the principle that, ―[w]ith 

few exceptions, the question whether a warrantless search of a home is reasonable 

and hence constitutional must be answered no.‖ Kyllo, 533 U.S. at 31 (observing 

that ―[a]t the very core of the Fourth Amendment stands the right of a man to 

retreat into his own home and there be free from unreasonable governmental 

intrusion‖ (internal quotation marks omitted)). 

In this case, the cell-site simulator alerted the officers that appellant‘s phone 

was located in the 4000 block of Minnesota Avenue, N.E., a block on which there 

were several businesses, a District of Columbia government building, and a Metro 

station. There appears to be no evidence in the record that there were residential 

buildings in the block, but amici note that a large apartment building is also located 

on the block, at 4020 Minnesota Avenue. There appears to be no evidence in the 

record that the cell-site simulator came within range of that apartment building as 

the officers were ―coming down southbound Minnesota [Avenue].‖ 

9

 See Graham, 824 F.3d at 435 (noting that in Jones, ―the concurring 

justices recognized a line between  ̳short-term monitoring of a person‘s movements 

(continued...)
58

property of appellant;10 and (4) did not involve a search of the contents of 

 

(...continued)

on public streets,‘ which would not infringe a reasonable expectation of privacy, 

and  ̳longer term GPS monitoring,‘ which would‖ (quoting Jones, 565 U.S. at 

430)). The concern is that long-term historic location information can reveal ―a 

wealth of detail about [an individual‘s] familial, political, professional, religious, 

and sexual associations.‖ Jones, 565 U.S. at 415 (Sotomayor, J., concurring); id. at 

430 (Alito, J., concurring in judgment) (―[T]he use of longer term GPS monitoring 

[over a period of twenty-eight days in Jones‘s case] in investigations of most 

offenses impinges on expectations of privacy.‖); cf. United States v. Riley, 858 

F.3d 1012, 1013 (6th Cir. 2017) (tracking of fugitive‘s real-time GPS location data 

for approximately seven hours did not amount to a Fourth Amendment search).

10

 A trespassory search implicating the Fourth Amendment occurs when the 

government ―gains evidence by physically intruding on constitutionally protected 

areas.‖ Florida v. Jardines, 569 U.S. 1, 16 (2013). 

Appellant and the majority opinion cite cases suggesting that use of a cellsite simulator could constitute trespass to chattels, ante at 24–25 n.27, but my 

colleagues do not rely on that case law for their conclusion. Moreover, as Justice 

Alito noted in his concurrence in the judgment in Jones, ―today there must be some 

actual damage to the chattel before [an] action [for trespass to chattels] can be 

maintained.‖ 565 U.S. at 419 n.2 (Alito, J., concurring in judgment) (internal 

quotation marks omitted); see also Restatement (Second) of Torts § 218 cmt. (e) 

(1965) (stating that, generally, ―one who intentionally intermeddles with another‘s 

chattel is subject to liability only if his intermeddling is harmful to the possessor‘s 

materially valuable interest in the physical condition, quality, or value of the 

chattel, or if the possessor is deprived of the use of the chattel for a substantial 

time‖). If arguendo use of the cell-site simulator in this case (which, according to 

the evidence, may have caused calls that appellant tried to initiate to be dropped) 

did constitute a trespass, I do not believe we could reasonably conclude that the 

police were culpable in failing to recognize it as such (and thus I believe we would 

have no occasion to apply the exclusionary rule). See Herring v. United States, 

555 U.S. 135, 141, 143 (2009) (confirming that ―exclusion has always been our 

last resort, not our first impulse‖ and that the Court has ―never suggested that the 

exclusionary rule must apply in every circumstance in which it might provide 

marginal deterrence,‖ and stating that ―[t]he extent to which the exclusionary rule 

(continued...)
59

appellant‘s cell phone that could have exposed his private information,11 I am 

unpersuaded that there was a Fourth Amendment violation in this case.

In the pages that follow, I will explain my reasoning in more detail. But 

first, I must address a preliminary issue.

I.

After oral argument in this matter, this court directed the parties to submit 

supplemental briefs on the following issue:

What reasonable and legitimate expectation of privacy 

 

(...continued)

is justified . . . varies with the culpability of the law enforcement conduct.‖) 

(internal quotation marks omitted). And, as discussed infra, even if police 

interfered with the operation of appellant‘s ―chattel‖ when the cell-site simulator 

―grabbed‖ his cell phone remotely and rendered it temporarily non-operational for 

making calls, police were justified in effecting that seizure of appellant‘s cell 

phone under the automobile exception to the warrant requirement.

11

 ―[C]oncerns about a general  ̳erosion of privacy‘ with respect to cell 

phones . . . revolve around protecting the large quantity of information stored on 

modern cell phones and on remote servers like the  ̳cloud.‘ If all that information 

were indeed at risk of disclosure [through the government‘s obtaining cell-site 

location information], we would share this concern.‖ Graham, 824 F.3d at 434 

n.13 (internal citation omitted). Documents, however, ―stored on phones and 

remote servers are protected, as  ̳content,‘ in the same way that the contents of text 

messages or documents and effects stored in a rented storage unit or office are 

protected.‖ Id.
60

does a person have in his or her location information 

when the person possesses (outside his or her residence) 

a stolen cell phone capable of being located by a cell-site 

simulator or through real-time cell site location 

information available to the cell phone owner or his or 

her telecommunications provider?

Asserting that the issue the court raised was waived by the government, 

appellant argues in his supplemental brief that ―waiver rules preclude this court 

from affirming the trial court‘s ruling on an alternative ground that the government 

did not raise at trial or on appeal.‖ I disagree in the strongest terms.12 Fourth 

Amendment suppression issues are serious issues. In this case, the evidence 

sought to be suppressed relates to serial sexual assaults and robberies at knifepoint 

(with use of a knife that the assailant — confirmed by DNA evidence to be 

appellant — was still carrying on his person at the time he was stopped by police). 

We have a duty to analyze for ourselves the antecedent question of whether, on the 

 

12

 Appellant is also incorrect in suggesting that the court directed briefing 

on an issue entirely absent from the government‘s initial brief in this court and its 

arguments in the trial court. The government argued in its opening brief to us that 

in cases cited by appellant, ―the cell-site simulator located the defendant‘s phone 

inside a home, thus implicating Fourth Amendment privacy concerns not raised 

here.‖ Our inquiry about the significance of the fact that appellant possessed the 

stolen cell phone outside his residence reflected in part that argument. Our inquiry 

also reflected the prosecutor‘s repeated argument (to which she mistakenly referred 

as involving application of the ―inevitable discovery‖ doctrine) to the trial court 

that suppression was not warranted because there was ―a separate, lawful way 

[police] could have gotten to the same thing‖ (emphasis added) — i.e., use of the 

cell-site simulator to target the stolen cell phone that was traveling with appellant‘s 

phone. 
61

particular facts of this case, use of the technology by which appellant was located 

constituted a search (and, if so, whether it was a lawful search). In this case as 

always, this court‘s task is to ―consider[] the briefs and the oral argument, and [to] 

test[] them against the record and the law,‖ Watson v. United States, 536 A.2d 

1056, 1068 (D.C. 1987) (en banc), not merely to choose the better or best of the 

arguments presented in support of a claim. Our responsibility as an appellate court 

is to decide cases in accordance with the law, and that responsibility is not to be 

diluted by how counsel have framed the issues or by limitation to the specific 

authorities counsel have cited. 

The Supreme Court‘s decision in United States National Bank of Oregon v. 

Independent Insurance Agents of America, Inc., 508 U.S. 439 (1993), is 

instructive. That litigation commenced after the Comptroller of the Currency 

issued a ruling allowing the United States National Bank of Oregon ―to sell 

insurance through its branch in Banks, Oregon.‖ Id. at 443. Trade organizations 

challenged the Comptroller‘s decision, arguing, inter alia, that it was inconsistent 

with section 92, a statutory provision enacted in 1916 that ―permit[ted] banks 

located in small communities to sell insurance to customers outside those 

communities.‖ Id. at 441, 444. The District Court granted summary judgment in 

favor of the Comptroller, finding that ―the Comptroller‘s interpretation was 
62

rational and consistent with section 92.‖ Id. at 444 (internal quotation marks and 

alterations omitted). On appeal, the trade organizations did not ask the Court of 

Appeals for the District of Columbia to rule that section 92 no longer existed (it 

had been repealed in 1918), and they did not take a position on the issue during 

oral argument or in supplemental briefing. Nevertheless, reasoning that it had ―a 

 ̳duty‘ to [decide the issue],‖ the Court of Appeals determined that section 92 had 

been repealed. Id. at 444-45 (quoting Indep. Ins. Agents of America, Inc. v. Clarke, 

955 F.2d 731, 734 (D.C. Cir. 1992)). 

The case went to the Supreme Court, which concluded that ―[t]he Court of 

Appeals . . . had discretion to consider the validity of section 92,‖ and ―did not 

stray beyond its constitutional or prudential boundaries‖ in doing so. Id. at 447. 

The Court explained that ―[t]hough the parties did not lock horns over the status of 

section 92, they did clash over whether the Comptroller properly relied on section 

92 as authority for his ruling,‖ and the Court of Appeals was not obliged ―to treat 

the unasserted argument that section 92 had been repealed as having been waived.‖ 

Id. at 446-47. The Court confirmed that  ̳―when an issue or claim is properly 

before the court, the court is not limited to the particular legal theories advanced by 

the parties, but rather retains the independent power to identify and apply the 

proper construction of governing law.‖‘ Id. at 446 (internal alterations omitted) 
63

(quoting Kamen v. Kemper Fin. Servs, Inc., 500 U.S. 90, 99 (1991)). The Court 

further instructed that ―a court may consider an issue  ̳antecedent to and ultimately 

dispositive of‘ the dispute before it, even an issue the parties fail to identify and 

brief.‖ Id. at 446-47 (internal alterations omitted) (quoting Arcadia v. Ohio Power 

Co., 498 U.S. 73, 77 (1990)). 

Our court has applied the guidance of National Bank of Oregon in various 

circumstances. For example, in Martin v. United States, 952 A.2d 181(D.C. 2008), 

after requesting supplemental briefs from the parties, we reached the question of 

whether the police had unlawfully entered Martin‘s home in violation of the Fourth 

Amendment, even though ―appellate counsel [had] failed to argue that the entry 

itself constituted an unlawful search either in his principal brief or at oral 

argument.‖ Id. at 188–89.13 Our sister court, the United States Court of Appeals 

 

13

 See also Anthony v. United States, 935 A.2d 275, 282 n.10 (D.C. 2007) 

(―But no matter whose ox is gored when the parties are directed by the court to file 

supplemental submissions,  ̳this court has frequently requested post-argument 

briefing of issues not adequately raised by counsel, to the end that, after both 

parties have been fully heard, the court is in the best position to render a sound 

decision.‘‖ (quoting Randolph v. United States, 882 A.2d 210, 226 (D.C. 2005)); 

Outlaw v. United States, 632 A.2d 408, 410–11 (D.C. 1993) (declining to reach the 

question briefed by the parties — ―whether one may be convicted of being an 

accessory after the fact to murder on the basis of actions taken while the decedent 

was still alive‖ — and instead, after requesting and receiving supplemental 

briefing, ruling based on an issue the panel raised for the first time at oral argument 

— ―whether the evidence was sufficient to support [appellant‘s] conviction of 

(continued...)
64

for the District of Columbia Circuit, has also considered the merits of issues the 

parties did not raise. See United States v. Maynard, 615 F.3d 544, 560–61 (D.C. 

Cir. 2010) (―The Government does not separately raise, but we would be remiss if 

we did not address, the possibility that although the whole of Jones‘s movements 

during the month for which the police monitored him was not actually exposed to 

the public, it was constructively exposed because each of his individual 

movements during that time was itself in public view.‖).14 

 

(...continued)

[accessory after the fact] to any offense whatever‖); cf. Randolph, 882 A.2d at 

217–18 ( ̳―Once a claim is properly presented to the trial court, a party can make 

any argument in the appellate court in support of that claim[, and] parties are not 

limited to the precise arguments made below.‖‘ (internal alterations omitted) 

(quoting West v. United States, 710 A.2d 866, 868 n.3 (D.C. 1998)); see also id. at 

227 (determining that ―the judgment should be affirmed on harmlessness grounds, 

notwithstanding the government‘s initial failure to argue that the trial court‘s error 

was harmless‖). 

14

 See also Lesesne v. Doe, 712 F.3d 584, 588 (D.C. Cir. 2013) (noting that 

the Supreme Court ―has recognized that  ̳there may always be exceptional cases or 

particular circumstances which will prompt a reviewing or appellate court, where 

injustice might otherwise result, to consider questions of law which were neither 

pressed nor passed upon by the court or administrative agency below,‖‘ and 

determining that ―the proper interpretation of [the Prison Litigation Reform Act‘s] 

exhaustion requirement is a dispositive legal issue antecedent to its application‖ 

(internal alterations omitted) (quoting Hormel v. Helvering, 312 U.S. 552, 557 

(1941))); United States v. Pryce, 938 F.2d 1343, 1348 (D.C. Cir. 1991) (―Only if 

one adopts an absolutist approach to the adversary system can one contend that 

courts must never address unargued issues, no matter how obvious their proper 

resolution may be. Certainly the Supreme Court rejects such an approach.‖).
65

In short, case law does not bind us to the approach of addressing only the 

arguments the parties have framed. The Supreme Court has not followed or 

dictated that approach,15 our neighbor the United States Court of Appeals for the 

District of Columbia Circuit has rejected it, and numerous other federal circuit 

courts of appeals have said that they have discretion on direct appeal to consider 

arguments a party has failed to make.16 The bottom line is that appellate courts 

―regularly and frequently consider sua sponte authorities not cited and grounds of 

decision not raised.‖17

 

15

 Commentators have frequently mentioned that in Erie Railroad Co. v. 

Tompkins, 304 U.S. 64 (1938), the issue the Court resolved — whether ―in 

diversity cases the substantive law of the state of trial must be applied‖ — ―had not 

been raised by the parties before either the lower courts or the Supreme Court.‖ 

Albert Tate, Jr., Sua Sponte Consideration on Appeal, 9 TRIAL JUDGES J. 68 

(1970), reprinted in APPELLATE JUDICIAL OPINIONS 128 (Robert A. Leflar ed., 

1974); see also Singleton v. Wulff, 428 U.S. 106, 121 (1976) (―The matter of what 

questions may be taken up and resolved for the first time on appeal is one left 

primarily to the discretion of the courts of appeals, to be exercised on the facts of 

individual cases. We announce no general rule.‖). 

16

 See, e.g., United States v. Rose, 104 F.3d 1408, 1414 (1st Cir. 1997) (―We 

join several other circuit courts of appeals in holding that appellate courts have the 

discretion on direct appeal to overlook the government‘s failure to argue that the 

admission of the challenged evidence, if error, was harmless, and that appellate 

courts may therefore consider the issue of harmlessness sua sponte.‖) (collecting 

cases).

17

 Albert Tate, Jr., supra note 15, at 127; see also Estate of Girard v. Laird, 

621 A.2d 1265, 1268 n.3 (Vt. 1993) (citing the Tate article in explaining why the 

court may ―reach[] results for reasons different than those argued by the parties‖); 

State v. Weber, 471 N.W.2d 187, 199 n.7, 200 (Wis. 1991) (citing the Tate article 

(continued...)
66

When we review denials of motions to suppress, ―our role is [essentially] to 

ensure that the trial court had a substantial basis for concluding that no 

constitutional violation occurred.‖ Brown v. United States, 590 A.2d 1008, 1020 

(D.C. 1991). ―We must determine whether the court‘s denial of the motion to 

suppress is sustainable under any reasonable view of the evidence,‖ and ―[i]t is 

well settled that [we] may affirm a decision for reasons other than those given by 

the trial court.‖ Alston v. United States, 518 A.2d 439, 440 n.2 (D.C. 1986). Thus, 

in this case, we have a duty to study carefully the particular facts of the case to 

determine for ourselves whether the trial court‘s denial of appellant‘s motion to 

suppress is sustainable. This means that we have not only the discretion to 

consider, but an obligation to consider whether appellant had a reasonable and 

legitimate expectation of privacy in his location information when (as the 

supplemental briefing order described and among other material facts discussed 

below) he ―possesse[d] (outside his . . . residence) a stolen cell phone capable of 

being located by a cell-site simulator or through real-time cell-site location 

information available to the cell phone owner or his . . . telecommunications 

provider.‖ 

 

(...continued)

in justifying its decision upholding the reasonableness of a search under the Fourth 

Amendment on grounds that, according to the dissenting justice, the State ―was 

aware of . . . but did not argue . . . in this court‖).
67

As explained in the discussion below, ―the antecedent question of whether 

there [wa]s a Fourth Amendment  ̳search‘ at all‖18 turns on resolution of that issue 

(which, on the facts presented here, is ultimately dispositive of the case). And 

even if arguendo use of the cell-site simulator constituted a ―search‖ for Fourth 

Amendment purposes, application of the automobile exception to the Fourth 

Amendment warrant requirement requires affirmance of the trial court‘s denial of 

the motion to suppress. 

II.

The Fourth Amendment protects ―[t]he right of the people to be secure in 

their persons, houses, papers, and effects, against unreasonable searches and 

seizures.‖ U.S. Const. amend. IV. Thus, in analyzing a Fourth Amendment claim, 

the threshold issue is whether there has been a ―search‖ or ―seizure.‖ That 

―antecedent question whether or not a Fourth Amendment  ̳search‘ has occurred is 

not so simple under [Supreme Court] precedent.‖ Kyllo, 533 U.S. at 31. The 

fundamental principle, however, is that ―a Fourth Amendment search does not

occur . . . unless the individual manifested a subjective expectation of privacy in 

the object of the challenged search, and society is willing to recognize that 

 

18

 Riverdale Mills Corp. v. Pimpare, 392 F.3d 55, 63 (1st Cir. 2004).
68

expectation as reasonable.‖ Id. at 33 (internal quotation marks and alterations 

omitted). ―[W]hether an expectation of privacy is reasonable depends in large part 

upon whether that expectation relates to information that has been  ̳exposed to the 

public.‘‖ Maynard, 615 F.3d at 558 (internal alterations omitted) (quoting Katz v. 

United States, 389 U.S. 347, 351 (1967)). ―In considering whether something is 

 ̳exposed‘ to the public as that term was used in Katz[,] we ask not what another 

person can physically and may lawfully do but rather what a reasonable person 

expects another might actually do.‖ Id. at 559.

A. Appellant had no reasonable expectation of privacy in his location 

while he was on the public roads with the powered-on, stolen cell 

phone.

It appears that police used the cell-site simulator to locate appellant‘s phone 

rather than the stolen phone. However, appellant‘s expectation of privacy with 

respect to the location of his phone need not come into play in our resolution of 

this case because appellant exposed that location to discovery by being on the 

public roads with both his phone and the powered-on, stolen cell phone. Even if 

appellant generally had a subjective expectation that information about his cell 

phone‘s location would be private, he could not have had a reasonable expectation 

that the location of his cell phone would remain private while he was traveling on 

the public roads with a powered-on, stolen cell phone. 
69

The sexual assaults and robberies in this case occurred in 2013. Well before 

that time, Apple had introduced the Find My iPhone application (―app‖). See In re 

J.A., No. A-1624-14T2, 2016 N.J. Super. Unpub. LEXIS 430, *11 n.3 (Super. Ct. 

App. Div. Feb. 29, 2016) (noting that ―Apple introduced the Find My iPhone 

feature in 2011‖ and that, in that case, the Find My iPhone app ―allowed police to 

track J.A. by following the stolen iPhone‘s signal to the Shelbourne Lane address 

within minutes of the robbery‖). And indeed in this case, one of the detectives 

working on the case, Detective Rachel Pulliam, testified that she had ―one of the 

complainant‘s information in [her] phone as well [as] in the Find My iPhone app‖ 

(and thus was able to ―get a general idea of where‖ she would be going to meet the 

TSU officers who had located appellant through use of the cell-site simulator). It 

appears that the detective was referring to her ability to use the Find My iPhone 

app in an effort to locate the Apple iPhone 4S cell phone stolen from the woman 

the police referred to as complainant number one‘s cousin (who was robbed but not 

sexually assaulted at the end of the first of the two incidents involved in this case). 

As it happened, police in this case tracked the stolen Sprint phone and not that 

iPhone, but case law is replete with references to iPhone owners or law 

enforcement officers locating stolen iPhones by using the Find My iPhone app in 

2013 or earlier years.19 The facts caution against assuming that the Find My 

 

19

 See, e.g., People v. Easton, No. H041704, 2017 Cal. App. Unpub. LEXIS 

(continued...)
70

iPhone app or similar find-my-device apps always pinpoint an address or do so 

 

(...continued)

644, *5 (Jan. 30, 2017) (―Using the Find My iPhone application [in 2012], police 

recovered Casey‘s cell phone from a recycling bin in front of a residence in Santa 

Clara within a few blocks of defendant‘s residence.‖); State v. Copes, No. 84, 2017 

Md. LEXIS 478, *5 n.4 (July 28, 2017) (citing a November 2011 publication 

entitled ―How to Use Find My iPhone to Get Your Stolen iPhone Back‖); People v. 

Foy, 199 Cal. Rptr. 3d 208, 212 (Ct. App. 2016) (―Wang had an application on his 

iPhone called  ̳Find My iPhone,‘ which he used [in 2011] at the suggestion of 

police to track Song‘s stolen iPhone. Wang‘s phone displayed a map indicating 

that Song‘s phone was located at 603 Grant Street[.]‖); People v. Robinson, No. 

3268/2013, 2016 N.Y. Misc. LEXIS 652, * 3, (App. Div. Feb. 24, 2016) (―As they 

were driving [in 2013], the  ̳Find My iPhone‘ tracker showed the [stolen] phone to 

be moving. The movement stopped at East 120th Street and First Avenue in 

Manhattan.‖); People v. Snyder, No. B265391, 2016 Cal. App. Unpub. LEXIS 

8230, *2 (Nov. 16, 2016) (―Using another device‘s  ̳find my iPhone‘ feature [in 

2013], Jordyn tracked her iPhone‘s location to the Mentor Court residence.‖); 

People v. Scales, No. B260902, 2016 Cal. App. Unpub. LEXIS 1942, *7-8 (Mar. 

17, 2016) (―[A] Los Angeles Police Department . . . Officer . . . used a  ̳Find My 

iPhone App‘ [in 2012] to locate Schulz‘s cell phone that had been taken during the 

robbery events. It was found on the side of the 10 Freeway about two miles away 

from the Green Path building.‖); Adams v. State, No. 1142, 2016 Md. App. LEXIS 

457, *3 n.3 (Ct. Spec. App. Feb. 5, 2016) (―Because Myers‘ cell phone was inside 

his [stolen] vehicle, police [in 2013] were able to locate the car by tracking the 

phone by use of the  ̳find my iPhone‘ application.‖); Commonwealth v. Gil, No. 

566-EDA-2014, 2015 Pa. Super. Unpub. LEXIS 3695, *2 (Feb. 10, 2015) (―After 

the victim reported the robbery [in 2012], the police tracked the iPhone, through a 

 ̳Find My iPhone‘ mobile application, to a house on Washington Street.‖); State v. 

Coleman, No. W2012-00880-CCA-R3-CD, 2013 Tenn. Crim. App. LEXIS 573, *3 

(June 10, 2013) (―Mr. Petty recalled that there was an application on his wife‘s 

phone called  ̳Find My iPhone.‘ Mr. Petty was able to use his computer to track 

the phone‘s location to a general vicinity of Division and Waddell Street.‖); Pirozzi 

v. Apple, Inc., 966 F. Supp. 2d 909, 915 (N.D. Cal. 2013) (quoting a statement 

from Apple‘s website that ―In the event your iPhone is lost or stolen, Find My 

iPhone allows you to locate it on a map[.]‖); United States v. Flores-Lopez, 670 

F.3d 803, 808 (7th Cir. 2012) (referring to the Find My iPhone app).
71

accurately,20 or that the only method officers used in the reported cases to locate 

the stolen phones was such an app (and not, for example, the app supplemented 

with use of a cell-site simulator). But the relevant point is that, in 2013, the public 

had reason to know that, because of ―the ubiquity of . . . apps,‖21 it was quite 

possible for a stolen cell phone to be tracked with precision, even if such efforts 

were not always successful. 

Further, even aside from the apps available to cell phone owners, cellular 

service providers have long been able to supply cell phone locational data in close 

to real-time,22 and, as at least one court observed in 2010, the providers‘ 

capabilities were increasing.23 In 2013, it would have been reasonable to expect 

 

20

 Detective Pulliam testified that the Find My iPhone app showed her 

―[not] an exact, pinpointed location‖ but, at one point, ―a general area . . . in 

southeast‖ (perhaps the area of the District into which the phones traveled when, 

according to other evidence, they left Capitol Heights, Maryland, and headed 

toward Kenilworth Avenue). 

21

 Commonwealth v. Wilson, No. 15-P-851, 2016 Mass App. Unpub. LEXIS 

466, *3 (Apr. 29, 2016).

22

 The evidence in this case showed that the police TSU received updated 

location information from the cellular service providers at least every fifteen 

minutes (every five minutes for the stolen Sprint phone), with only a one-to-threeminute lag time. 

23

 The following observations made by that court in 2010 are notable: 

―Neither the user nor the carrier can predict how precise the next location data will 

be. For a typical user, over time, some of that [location] data will likely have 

(continued...)
72

that the owner of the stolen cell phone might try to locate it by obtaining cell-site 

location information from her cellular service provider. Surely ―[t]he availability 

and use of [the foregoing] and other new devices . . . shape the average person‘s 

expectations about the privacy of‖ cell phone movements and location. Jones, 565 

U.S. at 429 (Alito, J., concurring in judgment).24 Further, it was reasonable to 

expect that the owner of the stolen cell phone would seek help from the police and 

put in motion their efforts, with whatever cell-site location information and devices 

were at their disposal, to locate the stolen phone. As police TSU Sergeant Perkins 

testified, with the cell phone simulator, ―either one [i.e., the stolen phone or 

appellant‘s phone] would have got us to the area [where they found appellant in his 

 

(...continued)

locational precision similar to that of GPS‖; ―Emerging versions of the technology 

are even more precise‖; ―[T]he tech-savvy user may now understand that there is a 

risk that the provider can calculate and record his location and movements very 

precisely.‖ In re Application for United States for Historical Cell Site Data, 747 F. 

Supp. 2d 827, 833-34, 845 (S.D. Tex. 2010), rev’d on other grounds, 724 F.3d 600 

(5th Cir. 2013).

24

 Such considerations led the Second Circuit to observe that ―any 

expectation of privacy that [the defendant] had in his cell-phone location [tracked 

over a less-than-two-hour period] was dubious at best.‖ United States v. 

Caraballo, 831 F.3d 95, 105 (2d Cir. 2016). See generally United States v. 

Wheeler, 169 F. Supp. 3d 896, 908 (E.D. Wis. 2016) (noting that ―[t]he media is 

rife with information — and sometimes warnings — about the fact that one‘s 

location can be tracked from one‘s cell phone‖). 
73

car].‖25 

By traveling with the stolen cell phone that was susceptible to all the 

foregoing find-the-phone methods and devices, appellant exposed his location, too. 

I therefore find it impossible to conclude that appellant could reasonably have 

expected that his movements and location with the stolen phone in his possession 

would be private (and thus that he had an ―expectation of privacy in his phone‘s 

location‖). Moreover, if appellant had such an expectation, I suspect that it is not 

one that society is prepared — and in my view it is not one that we should be 

prepared26 — to recognize as reasonable. To be sure, our cell phones play such a 

central role in our lives and contain so much of our personal data that we must be 

vigilant about protecting against government intrusions into cell phone privacy. 

But the other side of that coin is that — I strongly suspect — a great many people 

who have had a cell phone stolen or who fear such a theft are likely to have a 

 

25

 Appellant suggests that the evidence indicated that the cell-site simulator 

did not work with the stolen cell phone, but the trial court declined to so find. The 

court found instead that if the TSU officers ―had . . . switched over . . . to use the 

Sprint number instead, . . . they would have eventually gotten to the exact same 

place because the phones were together.‖ 

26

 I have in mind the caution that where we may have been ― ̳conditioned‘ 

by influences alien to the well-recognized Fourth Amendment freedoms, a 

normative inquiry may be necessary to align‖ what we are prepared to recognize as 

legitimate privacy interests ―with the protections guaranteed in the Fourth 

Amendment.‖ Tracey v. State, 152 So. 3d 504, 525–26 (Fla. 2014).
74

strong desire to recover their stolen phones and to be unwilling to recognize as 

legitimate the locational-privacy interest of a person who is traveling the streets 

with a stolen phone.27 I am not the first to observe that ―many people may find the 

tradeoff [between electronic tracking technology and some diminution of privacy] 

as worthwhile.‖ Jones, 565 U.S. at 427 (Alito, J., concurring in judgment).

To be clear, the analysis above does not rely on the inevitable-discovery 

 

27

 My conclusion that appellant was traveling with a stolen phone as to 

which he had no locational-privacy interest does not depend on the jury verdict that 

he was the thief, i.e., the perpetrator of the robberies. Cf. Godfrey v. United States, 

414 A.2d 214, 214 (D.C. 1980) (―The real question is whether the [proponent of a 

motion to suppress] can be deemed to have a legitimate expectation of privacy in 

the thing or area searched and the item seized without reference to‖ an 

―unfortunate pretrial connotation that the proponent of the motion to suppress is 

guilty.‖) Rather it rests on the evidence presented at the suppression hearing that, 

when arrested, appellant had with him in his car all four stolen phones as well as 

the phone used by the perpetrator of the robberies and sexual assaults. (Unlike the 

defendant in McFerguson v. United States, 770 A.2d 66 (D.C. 2001) — a case 

Judge Farrell suggests is apposite, ante at 53 n.2 — appellant was not ―a street 

pedestrian [with] a reasonable expectation of privacy in covered objects associated 

with his person,‖ id. at 71). I believe we can say with confidence that even if 

appellant had disputed at the suppression hearing that he knew that the victims‘ 

(four) phones found in his possession had been stolen and had attempted to show 

that he had a legitimate possessory interest in and expectation of privacy with 

respect to the stolen Sprint phone, he would not have been able to carry his burden 

of so demonstrating. See Rakas v. Illinois, 439 U.S. 128, 130 n.1 (1978) (―The 

proponent of a motion to suppress has the burden of establishing that his own 

Fourth Amendment rights were violated by the challenged search or seizure.‖); 

Morton v. United States, 734 A.2d 178, 182 (D.C. 1999) (referring to defendant‘s 

―burden of showing that he had a protectible interest‖). 
75

doctrine to conclude that use of the cell-site simulator was lawful. As the majority 

opinion notes, the inevitable-discovery doctrine ―shields illegally obtained 

evidence from the exclusionary rule if the government can show, by a 

preponderance of the evidence, that the evidence  ̳ultimately or inevitably would

have been discovered by lawful means.‘‖ Gore v. United States, 145 A.3d 540, 

548 (D.C. 2016) (quoting Hicks v. United States, 730 A.2d 657, 659 (D.C. 1999)). 

The inevitable-discovery doctrine thus requires proof that a presumably lawful 

search process was actually underway; here, at least arguably, that would have 

entailed at a minimum having entered the pertinent number of the stolen cell phone 

(which police had obtained) into the cell-site simulator. There was some evidence 

that the TSU officers did that, but, in the trial court‘s view, not enough such 

evidence to enable the government to prove by a preponderance of the evidence 

that the officers used the cell-site simulator to find the stolen phone rather than 

appellant‘s phone. However, for purposes of my analysis focused on what 

appellant could reasonably have expected others to do, I have properly relied on 

what the police could have done with respect to the stolen cell phone (or, it 

appears, with respect to the cousin‘s stolen iPhone) that would have enabled them 

to locate appellant and his phone.

United States v. Gbemisola, 225 F.3d 753 (D.C. Cir. 2000), illustrates the 
76

point. There, law enforcement agents had installed and subsequently monitored an 

electronic tracking device in a package addressed to the defendant, which enabled 

the agents to know if and when the defendant opened the package — which he did 

while riding in the back of a taxicab. Id. at 756. Noting that the agents did not see 

when the box was opened, the D.C. Circuit concluded that no warrant was required 

for their use of the electronic device that reported when the box was opened 

because the ―decisive issue . . . [was] not what the officers saw but what they could 

have seen.‖ Id. at 759 (emphasis added). ―At any time, the surveillance vehicle 

could have pulled alongside of the taxi and the officers could have watched 

Gbemisola through its window. Indeed, the taxi driver himself could have seen the 

event simply by looking in his rear-view mirror or turning around.‖ Id.; see also 

Maynard, 615 F.3d at 560 (―[I]t was not at all unlikely Gbemisola would be 

observed opening a package while seated in the rear of a taxi[.]‖). Thus, the fact 

that the agents learned what they learned through an electronic device (one 

presumably not generally available to members of the public) was not the 

important factor; the important factor was that they, or someone else, could have 

learned that the defendant opened the package through lawful means.28

 

28

 It might be suggested that the analysis in Gbemisola is a straightforward 

application of the Supreme Court‘s ruling in United States v. Knotts, 460 U.S. 276 

(continued...)
77

The same point applies here. Again, police TSU Sergeant Perkins‘s 

testimony (and the trial court‘s finding) was that, with the cell-cite simulator, 

―either [phone] would have got[ten them] to [where they found appellant in his 

car].‖ In other words, officers could have found appellant‘s location through use 

of the cell-site simulator targeted at the stolen cell phone that was in his vehicle 

(the lawfulness of which approach appellant does not challenge, and likely has no 

 

(...continued)

(1983), about the lawfulness of use of a monitoring device that reveals no more 

than could be seen by visual surveillance. See id. at 282–84 (holding that the 

officers‘ conduct in monitoring signals from a beeper they had installed in a 

container the defendant subsequently placed in his car did not invade any 

legitimate expectation of privacy and did not constitute a Fourth Amendment 

search since the beeper surveillance revealed no more than could have been visible 

to the naked eye as the car traveled the public highway and raised no constitutional 

issues that visual surveillance would not also raise); see also United States v. Karo, 

468 U.S. 705, 714 (1984) (―[T]he monitoring of a beeper in a private residence, a 

location not open to visual surveillance, violates the Fourth Amendment rights of 

those who have a justifiable interest in the privacy of the residence.‖) (emphasis 

added). However, the Supreme Court‘s decision in Bond v. United States, 529 

U.S. 334 (2000), makes clear that what an individual exposes to the public is not 

limited to what can be learned through visual perception (outside a residence), but 

also includes what members of the public may be able to discern through 

predictable tactile actions. See id. at 338 (―When a bus passenger places a bag in 

an overhead bin, he expects that other passengers or bus employees may move it 

for one reason or another. Thus, a bus passenger clearly expects that his bag may 

be handled‖ and ―exposed to certain kinds of touching and handling.‖). I see no 

reason why the analysis of whether something is exposed to the public based on 

―what a reasonable person expects another might actually do,‖ Maynard, 615 F.3d 

at 559, should not include as well the find-my-stolen-phone efforts likely to be set 

in motion by an individual whose cell phone has been stolen. 
78

standing to challenge).29 The fact that (we presume) police officers actually found 

appellant‘s location by using the cell-site simulator on appellant‘s cell phone 

should not change the Fourth Amendment calculus.

B. The (assumed) fact that the police actually used the cell-site 

simulator as to appellant’s cell phone while it was on the public roads 

does not provide a basis for finding a Fourth Amendment violation.

My colleagues focus, however, on the apparent fact that the police entered 

the identifying number for appellant‘s cell phone into the cell-site simulator and 

thus used it to locate appellant‘s phone rather than the co-located stolen phone. 

They emphasize that ―when it comes to the Fourth Amendment, means . . . matter.‖ 

Ante, at 18 (quoting Maynard, 615 F.3d at 566). But, as the D.C. Circuit explained 

in Maynard, what matters with respect to the means employed is whether ―one‘s 

reasonable expectation of control over one‘s personal information would . . . be 

defeated‖ through that means of information gathering. 615 F.3d at 566. For the 

reasons already discussed, on the facts of this case, appellant had no reasonable 

expectation of control over the information about his location while he was on the 

 

29

 See Lucas v. United States, 411 A.2d 360, 363 (D.C. 1980) (―[I]t is not so 

clear that persons can always assume that the right to privacy extends to articles of 

contraband in their possession.‖); United States v. White, 504 F. App‘x 168, 172 

(3d Cir. 2012) (citing authority from several federal circuits that one who 

knowingly possesses a stolen item has no legitimate expectation of privacy with 

respect to it and no standing to challenge a search of it).
79

public roads with the powered-on, stolen cell phone in his possession. 

Moreover, while the ―means . . . matter‖ principle applies a fortiori when it 

comes to law enforcement efforts to learn about what is contained or is transpiring 

in a home,30 the principle applies with much less consistency when what is 

challenged as a ―search‖ took place on public roads. See Knotts, 460 U.S. at 282 

(explaining that the defendants had no legitimate expectation of privacy that was 

violated by use of a beeper, pre-installed inside a container of chemicals that the 

defendant purchased and put in his car, which sent signals to a police receiver and 

enabled police to track the movements of the car, because police could have 

tracked the car‘s movements by driving behind it); United States v. Patrick, 842 

F.3d 540, 545 (7th Cir. 2016) (concluding that because the defendant, located with 

use of a cell-site simulator, was at the time ―in a public place, where he had no 

legitimate expectation of privacy, [he could]not complain about how the police 

 

30

 See, e.g., Kyllo, 533 U.S. at 35 n.2 (analyzing whether use of a thermalimaging device, capable of detecting the amount of heat emanating from a home, 

constituted an unlawful search when, without a warrant, it was aimed at the home 

of an individual suspected of growing marijuana in his home using high-intensity 

lamps; reasoning that the ―comparison of the thermal imaging to various 

circumstances in which outside observers might be able to perceive, without 

technology, the heat of the home — for example, by observing snowmelt on the 

roof — is quite irrelevant. The fact that equivalent information could sometimes 

be obtained by other means does not make lawful the use of means that violate the 

Fourth Amendment‖ (internal citation omitted)).
80

learned his location.‖); see also Gbemisola, 225 F.3d at 759.

My colleagues ultimately acknowledge that ―certain forms of tracking [in 

public spaces] . . . do not invade a reasonable expectation of privacy.‖ Ante at 18. 

What they seem to regard as dispositive is that by using the cell-site simulator, the 

police ―actively induce[d] the phone to divulge its identifying information.‖ Ante

at 17. Judge Farrell sees as the critical fact that with the cell-site simulator, the 

police TSU officers ―commandeer[ed]‖ appellant‘s cell phone, turning it into a 

―self-investigative‖ tool. I have several responses. 

First, for a couple of reasons, I believe the foregoing characterizations 

somewhat overstate the facts. As one court has noted, ―cell phones identify 

themselves by an automatic process called  ̳registration,‘ which occurs 

continuously while the cell phone is turned on regardless of whether a call is being 

placed.‖ Tracey, 152 So. 3d at 507 n.1.31 That observation accords with the 

 

31

 See also Copes, 2017 Md. LEXIS 478, at *6 (―A cell site 

simulator . . . takes advantage of the fact that a cell phone — when turned on —

constantly seeks out nearby cell towers, even if the user is not making a call 

. . . When the cell site simulator is close enough, the target phone will connect to it 

as though it were a cell tower.‖); In re Application for Tel. Info. Needed for a 

Criminal Investigation, 119 F. Supp. 3d 1011, 1014 (N.D. Cal. 2015) (―[C]ell 

phones, when turned on and not in airplane mode, are always scanning their 

network‘s cellular environment. In so doing, cell phones periodically identify 

themselves to the closest cell tower — i.e., the one with the strongest radio signal 

(continued...)
81

testimony by defense telecommunications technology expert Ben Levitan in this 

case. See Levitan Aff. 5 (―When a phone attaches itself to a cell tower, it identifies 

itself by phone number and various codes.‖). In other words, identifying 

themselves constantly is what powered-on cell phones do, regardless of whether a 

cell-site simulator is in the area. Second, while the majority opinion accurately 

quotes TSU Sergeant Perkins‘s testimony that the cell-site simulator ―grabs [the 

target cell phone] and holds on to it for a minute,‖ the opinion does not recount 

Sergeant Perkins‘s additional explanation. Sergeant Perkins explained that ―by 

grabs it,‖ he meant that the cell site simulator ―just knows it‘s there,‖ much as one 

knows when he has arrived at a station he is looking for by scanning the radio dial. 

Mr. Levitan put it differently, explaining that cell phones ―generally connect 

themselves to the strongest cell tower signal that they detect,‖ and, in that vein, 

when a cell phone detects the cell-site simulator as having the strongest signal, it 

will ―break its connection with the cell phone network and reattach itself to the 

newly found . . . simulator.‖ The Department of Justice document entitled ―Dep‘t 

of Justice Policy Guidance: Use of Cell-Site Simulator Technology (Sept. 3, 

 

(...continued)

— as they move throughout their network‘s coverage area. This process[ is] 

known as  ̳registration‘ or  ̳pinging[.]‘ . . . Pinging is automatic and occurs 

whenever the phone is on, without the user‘s input or control.‖ (record citations 

omitted)).
82

2015), http://www.justice.gov/opa/file/767321/download (the ―DOJ Policy 

Guidance‖), states similarly that ―cellular devices in the proximity of the [cell-site 

simulator] identify the simulator as the most attractive cell tower in the area and 

thus transmit signals to the simulator that identify the device in the same way that 

they would with a networked tower.‖ Id. at 2. Thus — if it matters — it appears 

that it is cell phones that initiate contact with a cell-site simulator and not the other 

way around.32

In any event, my colleagues raise points that must be addressed when they 

emphasize that by using the cell-site simulator, the TSU officers took ―functional 

control‖ of and ―coopted [appellant‘s] phone, forcing it to do something [he] surely 

never intended it to do: reveal its identifying and location information to an entity 

 

32

 But see Andrews, 134 A.3d at 340 (citing testimony in that case that a 

cell-site simulator known as the Hailstorm ―is an active device that can send an 

electronic signal . . . and  ̳draw[] the phone to [the] equipment‖‘ (alteration in 

original)).

My colleagues also say that the cell-site simulator ―exploits a security 

vulnerability‖ of cell phones. Ante at 17. I would not call what happened here as 

exploitation of a cell phone security flaw, but as law enforcement‘s taking 

advantage of a security-enhancement feature that aids in the recovery of stolen or 

lost phones. It may place a person who is traveling on the roads with a poweredon, stolen cell phone (that circumstances show he knew to be stolen) in the position 

either of accepting the risk that at any moment the stolen cell phone or his own cell 

phone could be converted into a tracking device or, alternatively, turning the 

phones off, but I do not see why that is an improper choice to foist on the person.
83

other than a telecommunications provider.‖ Ante, at 24 n.27. Judge Farrell finds it 

―unpersuasive‖ ―to argue that appellant had no reasonable expectation of privacy in 

the police‘ use of his phone‖ for this purpose. Ante, at 47. One major problem for 

my colleagues‘ analysis, however, is that, as shocking or outrageous as the 

foregoing characterizations might sound, the officer‘s use of the cell-site simulator 

did not constitute a ―search‖ and thus was not a Fourth Amendment violation 

unless appellant had a reasonable and legitimate expectation of privacy with 

respect to the object of the challenged search: his location information. For the 

reasons already discussed, he did not while he was on the public roads with a 

trackable, stolen cell phone.

It is helpful to recall the facts of California v. Greenwood, 486 U.S. 35 

(1988). In Greenwood, a police detective asked the regular trash collector in 

Greenwood‘s neighborhood to pick up the plastic garbage bags that Greenwood 

had left on the curb in front of his house and to turn the bags over to the detective 

without mixing their contents with garbage from other houses. Id. at 37. The trash 

collector responded by cleaning his truck bin of other garbage, collecting the 

garbage bags from the street in front of Greenwood‘s house, and turning the bags 

over to the detective. Id. The detective searched through the trash and found items 

indicative of narcotics use. Id. at 37–38. The Greenwood respondents asserted 
84

―that they had, and exhibited, an expectation of privacy with respect to the trash 

that was searched by the police,‖ emphasizing that the trash had been placed on the 

street for collection at a fixed time and was contained in opaque bags, which the 

garbage collector was expected to pick up, mingle with the garbage of others, and 

deposit at the garbage dump. Id. at 39. The respondents also highlighted that 

―there was little likelihood that [the trash] would be inspected by anyone.‖ Id. The 

Supreme Court acknowledged that ―[i]t may well be that respondents did not 

expect that the contents of their garbage bags would become known to the police 

or other members of the public,‖ id. at 39, but reasoned nevertheless that the police 

conduct did not constitute a Fourth Amendment violation (because respondents 

―could have had no reasonable expectation of privacy in the inculpatory items that 

they discarded‖). Id. at 41. 

In my view, the intrusive police conduct in Greenwood, by which police 

officers converted the entire contents of respondent‘s trash into a database of 

information about his activities, was every bit as objectionable as the temporary 

―coopt[ing]‖ of appellant‘s cell phone. I suspect most of us would be outraged at 

the effrontery of law enforcement officials in systematically inspecting our trash. 

But that would not be enough to establish that police officers‘ systematic 
85

rummaging through our trash is a ―search‖ for Fourth Amendment purposes.33 

And any sense of outrage here is likewise not enough to establish that use of the 

cell-site simulator in the particular circumstances of this case violated appellant‘s 

Fourth Amendment rights.34

But even if we assume that the TSU officers‘ taking ―functional control‖ of 

and ―coopt[ing] [appellant‘s] phone‖ was a search and/or seizure for Fourth 

Amendment purposes, there is yet another consideration that, in my view, should 

preclude the court from concluding that the search/seizure was unlawful.35 The 

 

33

 Cf. Historical Cell Site Data, 724 F.3d at 615 (―We understand that cell 

phone users may reasonably want their location information to remain private, just 

as they may want their trash, placed curbside in opaque bags, . . . to remain so. But 

the recourse for these desires is in the market or the political process . . . . The 

Fourth Amendment, safeguarded by the courts, protects only reasonable 

expectations of privacy.‖ (internal citation omitted)).

34

 Another lesson from Greenwood is the principle on which Gbemisola, 

was decided: that if the individual does not have a reasonable expectation of 

privacy in the object of an activity that we would describe in ordinary parlance as a 

search, there is no search for Fourth Amendment purposes even if the manner in 

which law enforcement conducted their garbage inspection was not available to 

most members of the public. The Supreme Court observed in Greenwood that the 

respondents‘ trash was readily accessible to ―animals, children, scavengers, 

snoops, and other members of the public.‖ 486 U.S. at 40. But it is likely that few 

people other than the police would have been granted the accommodation of 

having the trash collector segregate all of the respondents‘ garbage from other 

garbage. 

35

 ―A  ̳seizure‘ of property occurs when  ̳there is some meaningful 

interference with an individual‘s possessory interests in that property.‘‖ Karo, 468 

(continued...)
86

police TSU officers could reasonably infer that the stolen cell phone and 

appellant‘s phone were traveling together in a car or other vehicle because the realtime location information showed them as having gone from Capitol Heights, 

Maryland, to Kenilworth Avenue, before moving to the 4000 block of Minnesota 

Avenue, N.E. The automobile exception to the Fourth Amendment warrant 

requirement ―permits the warrantless search of a car [or other vehicle] that is 

 ̳readily mobile‘ so long as  ̳probable cause exists to believe it contains 

contraband.‘‖ United States v. Eshetu, 863 F.3d 946, 951 (D.C. Cir. 2017)

(quoting Pennsylvania v. Labron, 518 U.S. 938, 940 (1996) (per curiam)); United 

States v. Shackleford, 830 F.3d 751, 753 n.2 (8th Cir. 2016) (―The automobile 

exception requires probable cause to believe contraband or evidence of any crime 

will be found in the vehicle[.]‖).36 And, ―[i]f probable cause justifies the search of 

 

(...continued)

U.S. at 712 (quoting United States v. Jacobsen, 466 U.S. 109, 113 (1984)). There 

was at least arguably a seizure here, because, according to the testimony, use of the 

cell-site simulator may have caused calls appellant tried to make from his phone to 

drop. (I note that to the extent that the presence of the cell-site simulator in the 

area caused dropped calls or other disruption of the cell phones of other people in 

the area, appellant has no standing to complain.)

36

 See also California v. Carney, 471 U.S. 386, 393 n.2 (1985) (―With few 

exceptions, the courts have not hesitated to apply the vehicle exception to vehicles 

other than automobiles.‖); id. at 392-93 (explaining that if a vehicle ―is readily 

capable of such use [on the highways] and is found stationary in a place not 

regularly used for residential purposes,‖ the ―justifications for the vehicle 

(continued...)
87

a lawfully stopped vehicle, it justifies the search of every part of the vehicle and its 

contents that may conceal the object of the search.‖ United States v. Ross, 456 

U.S. 798, 825 (1982); Eshetu, 863 F.3d at 952. 

―Probable cause exists when based on the known facts and circumstances, a 

reasonably prudent person would believe that contraband or evidence of a crime 

will be found in the place to be searched.‖ United States v. Charles, 801 F.3d 855, 

860 (7th Cir. 2015) (internal quotation marks omitted). Here, even before using 

the cell-site simulator, the police TSU officers had near real-time cell-site location 

information that gave them probable cause to believe that a vehicle was on the 

public roads with both the stolen cell phone and the cell phone used by the sexual 

assault/robbery perpetrator, and thus probable cause to believe that—whatever the 

subject vehicle‘s precise location on the roads37—it contained contraband and 

 

(...continued)

exception come into play,‖ because ―the vehicle is obviously readily mobile by the 

turn of an ignition key, if not actually moving‖); id. at 392 (―[I]ndividuals always 

have been on notice that movable vessels may be stopped and searched on facts 

giving rise to probable cause that the vehicle contains contraband, without the 

protection afforded by a magistrate‘s prior evaluation of those facts.‖ (internal 

quotation marks and alterations omitted)). And, there is exigency about searching 

a vehicle where there is probable cause to believe it contains contraband: ―[T]he 

overriding societal interests in effective law enforcement justify an immediate 

search before the vehicle and its occupants become unavailable.‖ Id. at 393.

37

 Cf. State v. Tate, 849 N.W.2d 798, 810 (Wis. 2014) (reasoning that even 

if a warrant had been required to authorize use of a cell-site simulator, the exact 

(continued...)
88

evidence of a crime. This means that — under the automobile exception — the 

vehicle was searchable without a warrant, and that any cell phones in it that might 

have been contraband or evidence of the crime could be seized.38 We should 

therefore hold that when the cell-site simulator simultaneously detected/caught the 

signal from appellant‘s cell phone (which was located in a car parked on the street) 

and ―seized‖ the phone by ―hold[ing] on to it for a minute,‖ there was no Fourth 

Amendment violation. Any locational information obtained from the cell phone 

was not content that could be searched only pursuant to a warrant.39 

 

(...continued)

place to be searched, such as a street address, was not required).

38 Our request for supplemental briefing signaled, without explicitly 

suggesting, that the automobile exception might be implicated on the facts of this 

case (and amici briefly addressed its applicability in their initial brief). 

39

 See Graham, 824 F.3d at 434 (rejecting the argument that cell-site 

location information should be treated as ―content‖ for Fourth Amendment 

purposes).

Again, this case does not involve a warrantless search of any digital content 

(such as text messages, emails, contact lists, call logs, voicemail messages, 

photographs, videos, files, internet browsing history, apps that are revelatory of a 

person‘s interests, historic location information, etc.) stored on appellant‘s cell 

phone, the conduct for which, the Supreme Court determined in Riley v. 

California, 134 S. Ct. 2473, 2485 (2014), a warrant was needed. See id. at 2480-

81 (involving a search of the cell phone that was found in Riley‘s pocket after he 

was stopped for driving with expired tags and subsequently arrested for possession 

of concealed and loaded firearms); see also DOJ Policy Guidance at 2 (―[T]he 

[cell-site] simulator does not remotely capture emails, texts, contact list, images or 

any other data from the phone.‖). The seizure, ―interfer[ence] with the 

functioning‖ of, or ―coopt[ing]‖ of appellant‘s phone involved here, including the 

(continued...)
89

***

I end by repeating and underscoring that my dissent rests on the particular 

facts of this case: Police had near real-time information, from cell phone 

providers, that the cell phone the robbery/sexual assault assailant had used to lure 

his victims was traveling on the public streets together with a trackable, poweredon cell phone stolen from one of the assailant‘s victims (who gave the police 

permission to obtain her phone records); they could infer that the phones were 

traveling together in a car or other vehicle; and law enforcement officers‘ use of a 

cell-site simulator in the vicinity led them to a ―handful of cars‖ parked at the 

Minnesota Avenue Metro station and to a car in which appellant sat with the stolen 

cell phone in his possession. To hold that the officers‘ use of the cell-site 

simulator in this case was lawful would come nowhere close to holding, as my 

colleagues conclude, that police may use cell-site simulators ―at will‖ to locate any 

individual who is carrying a cell phone, without regard to whether the individual is 

known to be in a vehicle moving through the public streets and without regard to 

 

(...continued)

effect of having his calls dropped, is akin to the interruptions or intrusions that the 

Riley Court found permissible when police officers execute a search incident to 

arrest that turns up a cell phone: they are ―free to examine the physical aspects of 

[the] phone,‖ may ―turn the phone off or remove its battery,‖ or may ―leave a 

phone powered on and place it in an enclosure that isolates the phone from radio 

waves.‖ 134 S. Ct. at 2485, 2487.
90

whether the individual is known to have with him in the vehicle both a trackable 

cell phone stolen during a set of robberies and the cell phone from which an 

assailant placed calls to lure his sexual assault/robbery victims. Quite the contrary, 

the holding I believe is the right one would, because of its nuanced analysis, sound 

a cautionary note about using a cell-site simulator in other circumstances without a 

warrant.40

What we should not do in resolving this appeal is to jump on the bandwagon 

of decrying what is claimed to be a Fourth Amendment violation from use of cellsite-simulator technology without recognizing how the particular, material facts of 

this case distinguish it from the cell-site simulator cases courts have decided before 

this one. The Supreme Court has recognized the need for ―consideration of case-

 

40

 In addition, even if I assume arguendo that there was a Fourth 

Amendment violation, I am doubtful that suppression in this case would ―pay its 

way,‖ United States v. Leon, 468 U.S. 897, 907 n.6 (1984), under the ―cost-benefit 

analysis in exclusion cases,‖ Davis v. United States, 564 U.S. 229, 238 (2011), 

particularly in light of the Department of Justice‘s announced general policy that 

the government now must seek warrants for cell-site simulator use. DOJ Policy 

Guidance at 3-4. ―[T]he [exclusionary] rule‘s operation [is limited] to situations in 

which th[e] purpose [of deterrence] is thought most efficaciously served‖; 

accordingly, ―[w]here suppression fails to yield appreciable deterrence, exclusion 

is clearly unwarranted.‖ Davis, 564 U.S. at 237 (internal alterations and quotation 

marks omitted).
91

specific exceptions to the warrant requirement‖;41 we are remiss if we do not 

carefully consider the distinguishing facts of this case; and the public deserves no 

less from us, even as we do what we must to protect precious Fourth Amendment 

rights. 

For all the foregoing reasons, I respectfully dissent from the judgment 

reversing appellant‘s convictions of two counts of first-degree sexual abuse while 

armed, two counts of kidnapping while armed, four counts of robbery while armed, 

and one count of threats. 

 

41

 Riley, 134 S. Ct. at 2486.