By Joshua Dansby

Joshua W. Dansby is a recent graduate of The George Washington University Law School and a member of the Washington State Bar. Joshua serves as a board member in a nonprofit and is currently a Charles F.C. Ruff Fellow at the Office of the Attorney General for the District of Columbia.


On May 11, 2015, Washington state’s governor, Jay Inslee, signed a bill into law that required state and local law enforcement to get a warrant before deploying cell site simulators. Cell site simulators, sometimes collectively referred as “Stingrays,” are based on a popular model of simulator. They aid officers by “mimic[king] a cellphone tower, getting a phone to connect to it and measuring signals from the phone.”1 This law received unanimous support in both the Washington State House and Senate and, by requiring a warrant, offers very strong procedural protections. In addition to requir­ing police officers to secure a warrant for a Stingray, it also requires them to discard cellphone data from people who are not the specific target of an investigation. The purpose is simple: to prevent law enforcement, under the auspices of investigating one person, from deploying a Stingray device that intercepts thousands of peoples’ private information. Federal law does not offer the same protections.

Since the Supreme Court’s decision in Smith v. Maryland, the judiciary has held that devices labelled as “pen registers” do not constitute a “search” under the Fourth Amendment; therefore, a probable cause warrant is not required.2 Over time the development of more sophisticated technologies, coupled with a “tough on crime” mentality that gave more power and resources to prosecutors and law enforcement, led to a practice where the definition of a “pen register” grew to include Stingray devices. This has allowed federal law enforcement to collect troves of information from parties they do not have cause to investigate, allowing them to effectively skirt the Fourth Amendment which requires a probable cause warrant for the collection and monitoring of other types of electronic information such as wiretaps.3 This is a continuation of the troubling trend we have seen from the judiciary; where courts, in the name of deference and security, abdicate their judicial role to “say what the law is.”4 Analyzing the current landscape of federal and state law in this area, the federal government should follow the lead of those states, such as Washington, which provide stronger protections for individual privacy under the Fourth Amendment.

Fourth Amendment rights

The language of the Fourth Amendment prohibiting unreasonable searches and seizures is open-textured and indefinite; moreover, it could not antici­pate the impact of every development of new technology in more than two hundred years since it was written:

The right of the people to be secure in their persons, houses, papers, and ef­fects against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirma­tion, and particularly describing the place to be searched, and the persons or things to be seized.5

In Olmstead v. United States, the Supreme Court first defined a “search” as a physical intrusion onto an individual’s private property—known as the physical trespass doctrine.6 By l imiting t he application of t he Fourth Amendment only to physical trespass, Olmstead permitted other kinds of surveillance.7 This approach changed in response to emerging technologies. Eventually, in Katz v. United States, the Supreme Court overturned Olmstead and set out a new constitutional standard that expanded Fourth Amendment protections to include individual privacy interests.8 Katz held that a “search” occurs when the government violates an individual’s “reasonable expecta­tion of privacy.”9 The Katz Court then established the following two-prong test for determining whether a “search” occurred, such that a probable cause warrant is required: (1) Whether an individual exhibited an actual expectation of privacy, and (2) whether society is prepared to recognize this expectation as reasonable.10

To conduct a “search,” the government must get a warrant issued upon probable cause.11 Probable cause is summarized as a reason, supported by sufficient objective evidence, to believe that a search will turn up evidence of criminal activity or contraband.12 Carroll v. United States explained that probable cause is a common-sense standard13 and, under Dumbra v. United States, probable cause requires only a “practical, non-technical”14 probability that incriminating evidence was involved.

The exclusionary rule,15 first described in Weeks v. United States,16 is a pro­phylactic rule that prohibits the introduction of unconstitutionally gathered evidence for purposes of prosecuting an individual in a criminal trial.17 In Elkins v. United States, the Supreme Court held that the exclusionary rule’s purpose is to compel respect for the Fourth Amendment by removing law enforcement’s incentive to disregard it.18 Although the exclusionary rule has been subject to many limitations and exceptions over time,19 it is still the primary enforcement mechanism for ensuring that law enforcement officers follow the requirements of the Fourth Amendment.

Smith V. Maryland: From pen registers to Stingrays

In Smith v. Maryland, the Supreme Court held that a law enforcement of­ficer’s use of a pen register—an electronic device that records all numbers called from a particular phone line—to collect information about an indi­vidual’s outgoing phone calls is not a “search” because the phone-user had “voluntarily conveyed numerical information to the telephone company.”20 The Court held that, because the phone-user disclosed his numerical infor­mation to the phone company so that they could connect his call, he did not have a reasonable expectation of privacy in the numbers he dialed under Katz. 21 In setting forth this reasoning, Smith created what is known as the “third party” rule.22

Notably, Smith made no distinction between connections made by a hu­man telephone operator versus automated equipment, nor did it focus on the relationship between the caller and the third party to whom the information was disclosed.23 This case placed pen registers completely outside Fourth Amendment protections, meaning that if there were to be any privacy protec­tions against law enforcement’s use of pen registers, those protections would have to be created by statute. Smith’s holding is problematic for two reasons: (1) the Supreme Court incorrectly applied Katz’s “reasonable expectation of privacy” test and (2) the decision has allowed law enforcement and the intelligence community to bypass the Constitution.

Smith was wrongly decided and should be overturned

Smith was wrongly decided because the Court incorrectly applied Katz’s “reasonable expectation of privacy” test. Under the first part of Katz, the court considers whether an individual has exhibited an actual expectation of privacy. This is the subjective part of the test. In Smith, the answer was clearly “yes.” When the phone-user in Smith called another person, he did not expect other people to be collecting and distributing all of the numbers he called. Indeed, the phone-user claimed that he thought his outgoing calls were private and protected by the Fourth Amendment, in part because he made them from the privacy of his own home.24

Nevertheless, the Smith Court, while not directly refuting this claim, asserted that, “Although petitioner’s conduct may have been calculated to keep the contents of his conversation private, his conduct was not and could not have been calculated to preserve the privacy of the number he dialed.”25 The Court stated that the location of where the phone-user made his calls were irrelevant because the numerical information transmitted to the phone company to connect a call would be conveyed in the exact same manner regardless of location.26 However, an acceptance of Smith’s reasoning means that an individual who uses a phone to make a call is never able to fulfill the subjective part of the Katz test. In other words, any person who dials a number to make a call has evidently performed conduct that is inconsistent with an expectation of privacy in calling that number.

Turning to the second prong of the Katz test, which considers whether an individual’s expectation of privacy was reasonable, the Smith majority incor­rectly concluded that, even if the phone-user had a subjective expectation of privacy, it was not “reasonable.”27 However, the correct answer is again, “yes.” People do not regard their outgoing call logs to be public information.28 The fact that telephone companies have made a habit of turning over their customers’ phone records to the police does not negate that expectation of privacy. As Justice Stewart stated in his dissent in Smith, “It is simply not enough to say, after Katz, that there is no legitimate expectation of privacy in the numbers dialed because the caller assumes the risk that the telephone company will disclose them to the police.”29

Finally, the majority in Smith did not distinguish the fact that the “third party” privy to the phone-user’s data was the phone company, more specifi­cally, a machine that uses the information to simply route and connect calls. To imply, as the majority did, that a routing machine is a person, hunched over a desk and eagerly scribbling down the numbers the phone-user calls in anticipation of handing that information over to police, is ludicrous. As noted by Justice Marshall in his dissent, “Since I remain convinced that constitutional protections are not abrogated whenever a person apprises another of facts valuable in criminal investigations, I respectfully dissent.”30 He further stated:

The use of pen registers . . . constitutes an extensive intrusion. To hold otherwise ignores the vital role telephonic communication plays in our personal and professional relationships, as well as the First and Fourth Amendment interests implicated by unfettered official surveillance. . . . Many individuals, including members of unpopular political organizations or journalists with confidential sources, may legitimately wish to avoid disclosure of their personal contacts. Permitting governmental access to telephone records on less than probable cause may thus impede certain forms of political affiliation and journalistic endeavor that are the hallmark of a truly free society. Particularly given the Government’s previous reliance on warrantless telephonic surveillance to trace reporters’ sources and monitor protected political activity, I am unwilling to insulate use of pen registers from independent judicial review.31

Justice Marshall’s opinion is as true today, if not more so, as it was in 1979. Today, in an age of omnipresent digital communication and intercon­nectedness, this role is even more apparent. We disclose information to many “third parties”—banks, phone companies, social media companies, to name a few—yet we expect each of those parties to protect that infor­mation.32 And society is ready to recognize this expectation of privacy as reasonable. Indeed, we long have.33 Smith v. Maryland should be overturned and pen registers should be classified as a “search” requiring a probable cause warrant.

Expanding the definition of a pen register to include Stingrays

Under Smith, absent statutory protections, law enforcement’s use of pen registers is not bound by any constitutional protections. As a result, law en­forcement and the intelligence community figured out a simple, yet clever, method to evade the Constitution: expand the scope of what constitutes a pen register to include cell site simulators.

In contrast to a pen register, which collects the basic numerical infor­mation of phone calls, once connected a Stingray can be used to access electronic serial numbers (ESNs) and a phone’s internal storage.34 Stingrays also have the capability to track a phone, intercept communications (includ­ing text, voice, and data), deny service, and extract encryption technology, among other functions.35

When it comes to similar privacy concerns, the Supreme Court has at­tempted to limit technological invasions. The Supreme Court has held that searches involving thermal imaging of a house,36 tracking a car via a GPS locator,37 and searching digital information on an individual’s cell phone during arrest are all subject to the Fourth Amendment and thus require a probable cause warrant.38 In contrast, under the Patriot Act and similar legislation, a Stingray is treated as a type of “pen register;”39 which means that individuals have no constitutional protection from such devices.

The refusal to differentiate Stingrays from pen registers and give them distinct legal consideration, along with the expansion of the definition of “pen register,” means that all a federal law enforcement officer needs to do in order to use a Stingray is get a pen register request approved by a judge.40 This process has been defined as “ministerial” rather than provid­ing meaningful judicial oversight,41 and simply requires law enforcement officers to meet the low burden of asserting that the information sought is “likely” to be “relevant” to a criminal investigation.42 The judge will then approve the request without even being made aware that a Stingray is the device that will be utilized.43 Thus, the powerful Stingray, a device never explicitly authorized by Congress44 or addressed by Supreme Court juris­prudence, is used aggressively and continues to evade the probable cause warrant requirement under the Fourth Amendment for what is certainly an invasive search.

Case study: Tacoma, Washington

On March 3, 2017, Pierce County Superior Court Judge Frank Cuthbertson fined the City of Tacoma over $50,000, plus legal fees, for violating Wash­ington State’s Public Records Act.45 The case arose when, pursuant to the Public Records Act, the Center for Public Policy, a good-governance group, requested the Tacoma Police Department’s (TPD) nondisclosure agreement (“NDA”) with the FBI concerning the TPD’s Stingray device.46 The TPD withheld most of the NDA through redactions, in violation of the Act, in part because of agreements it had made with the FBI to keep information related to the Stingray secret as a condition of receiving one.47

Judge Frank Cuthbertson ruled against the City of Tacoma, imposing the maximum penalty available under state law.48 After the victory, the Center for Public Policy’s attorney, David Whedbee stated, “Judge Cuthbertson said that this was a paradigm case in which the City favored its interests in maintaining good relations with the FBI at the expense of the public’s right to open government under the Public Records Act.”49 This is simply the lat­est development in the story of Tacoma’s adventure with Stingrays, which began in 2008 and eventually led to Washington State passing House Bill 1440 on May 11, 2015, which requires state law enforcement officers to get a warrant before utilizing Stingray technology.50

Around the same time, in August 2014, The News Tribune, a local Tacoma newspaper, published a story revealing that the TPD acquired and utilized a Stingray device in 2008.51 Following the flurry of follow-up stories about the extent of a Stingray’s capabilities (and a rather predictable public outcry), it was revealed that among those surprised by the revelation of Stingray use were the City Council members who approved software update purchases for the Stingray as well as the county judges who authorized law enforce­ment’s use of the device.52 When asked by Tribune reporters to comment on the City Council’s purchase, City Councilmember David Boe responded, “I’ve got to find out what I voted on before I comment.”53

At first blush, Boe’s response implies some level of incompetence, espe­cially considering that elected officials are supposed to provide an oversight and budgetary role for the City; however, it turned out that no Councilmember could recall being told the full capabilities of the equipment, much less that it would be used in to search, track, and collect information from phones.54 When the TPD briefed the Council, convincing them to purchase the equip­ment, the Stingray was described as a “boon to Tacoma’s bomb squad.”55 A detective writing a memo to the Council stated, “This new equipment offers enhanced technological capabilities for the Tacoma Police Department Ex­plosives Ordinance Detail [“EOD”] with IED [improvised explosive device] prevention, protection, response and recovery measures.”56 Shortly after the briefing, the City Council approved the quarter of a million-dollar purchase unanimously, apparently thinking that the device would be used to detect bombs rather than surveilling random phones.57 Perhaps more worrying than law enforcement misleading the Council, however, was law enforcement’s willingness to be even less transparent to those in the judicial branch.

From 2009 to 2015, the county’s Superior Court judges unwittingly signed more than 170 orders that Tacoma police and other local law enforcement agencies say authorized them to use a device that not only allows investi­gators to track a suspect’s cellphone but also sweeps cellphone data from innocent people nearby.58

After news broke about the TPD’s Stingray use, Assistant Police Chief Kathy McApline said that the police only used cell site simulators with a court’s permission.59 H owever, P residing J udge R onald C ulpepper’s r e­sponse was: “People have never heard of it.”60 He went on, “If they use it wisely and within limits, that’s one thing, I would certainly personally have some concerns about just sweeping up information from non-involved and innocent parties—and to do it with a whole neighborhood? That’s concern­ing.”61 When orders authorizing TPD’s use of pen registers were unsealed as part of the Tribune’s investigation, the orders revealed that neither the pen registers nor the affidavits filed by law enforcement mentioned that the Department had a Stingray and intended to use it.62 “Instead, detectives used language commonly associated with requesting an order that would force a cellphone company to turn over records for a particular phone, and, where possible, the real-time location of the phone.”63 With requests like these, it is not difficult to understand why the judges were surprised to discover that they had signed over 170 orders that, unbeknownst to them, were used to authorize the use of a Stingray device capable of sweeping up the intimate digital data of thousands of non-suspects.

When the TPD was asked whether all Stingray requests failed to inform judges of cell simulator use, police spokeswoman Loretta Cool stated that the TPD did not believe it was necessary to inform judges of the existence or contemplated use of the device. 64 Cool asserted that TPD officers were required to disclose only what crime they were investigating and what infor­mation they sought.65 The Superior Court of Pierce County disagreed, and within two months, in November 2014, the Court required language in the TPD’s pen register applications that clearly articulated the device’s intended use.66 The Court further issued a limiting order instructing law enforcement officers to discard the information of non-suspects.67 This was not done so much out of fear that the TPD was engaging in egregious violations of law, but as a simple matter of oversight by providing judicial checks and balances over a zealous law enforcement department with new technologies that move at a faster pace than court proceedings.

At the time of the TPD Stingray revelation, no other state or local law en­forcement agency in Washington acknowledged possession of such a device. This is still the case today.68 It is extraordinary then that, twenty-one months after the use of a single Stingray was revealed in Tacoma, Washington formu­lated new statutory privacy protections to address cell site simulators use.69 Further, despite a politically divided legislature, Washington unanimously passed legislation that required officers to get a warrant before using a cell site simulator, such as a Stingray, and to discard cellphone data of people who are not a specific target of a police investigation.70

The unusual bipartisan nature and speed at which this bill was made law has its roots in a simple belief that citizens’ privacy interests should be protected. The bill was motivated by the following factors: (1) there was no federal law extending regulation to Stingrays, (2) the State’s privacy laws did not cover the devices, and (3) judges could not provide meaningful over­sight and “authorize” law enforcement activity if law enforcement agencies entered into agreements wherein they promised to keep secret the activities judges are supposed to be authorizing. The state of Washington, starting with its judiciary and ending with its legislature, saw a gap in the law and filled it within twenty-one months. By comparison, the federal government has had roughly twenty-two years and thus far has failed to establish effective oversight of the federal government’s use of Stingrays.71

Applying lessons learned from the states to the federal government

Like Washington, other states—such as Indiana, Maine, Montana, Illinois, and Minnesota—have either passed legislation requiring law enforcement to get a probable cause search warrant before using a cell site simulator or are considering enacting such legislation.72 Based on these states’ approaches, the following proposals present possible remedies for the federal government to pursue in order to help rectify, or at least mitigate, the damage done to the Fourth Amendment via pen registers and Stingrays:

(1) The Supreme Court should overturn Smith v. Maryland and estab­lish that the use of pen registers and similar devices (such as cell site simulators, including Stingrays) constitute a “search” for purposes of the Fourth Amendment, which thus require a probable cause warrant. As such, pen register use would be treated analogously to other law enforcement searches such as thermal imaging,73 cell phone searches incident to arrest,74 and GPS tracking.75 The Court should also extend the exclusionary rule to cover evidence obtained via pen registers and require law enforcement officers to discard information collected from non-suspects.

(2) Through future case holdings, the federal judiciary should differentiate between pen registers and more technologically superior tools, such as Stingrays and cell site simulators, classifying the latter as a “search” for purposes of the Fourth Amendment, thus requiring a probable cause warrant. This would also include extending the exclusionary rule to evidence obtained through Stingrays without a warrant and require law enforcement to discard the information collected on non-suspects. This way, even if the courts were unwilling to extend Fourth Amendment protections to all pen registers, there would still be protection against the use of more invasive tools, such as Stingrays.

(3) Through legislation, Congress should provide that pen registers and, using broad language, similar technologies including Stingrays, should be utilized only after receiving a probable cause warrant from a federal judge. This legislation should also require law enforcement to destroy the information collected from non-suspects in order to protect indi­vidual privacy.

(4) Akin to proposal three, Congress should provide that Stingrays and cell site simulators should be utilized only after receiving a probable cause warrant from a federal judge. This legislation would be narrower since it would not target pen registers, thus leaving the holding of Smith in­tact. However, it would differentiate pen registers from the technologi­cally superior Stingray devices and include provisions that order law enforcement to destroy the information collected from non-suspects to protect privacy.

(5) Finally, federal judges should order that law enforcement officers must detail their intended use of pen register authorizations (under which Stingrays would presumably, and unfortunately, still be included). This would provide more oversight, or “checks,” on law enforcement activity and make authorizations less of a ministerial process, or rubber stamp­ing, as they have become. Federal judges should also order that law enforcement must destroy information collected from non-suspects. This solution resembles the aforementioned efforts of Pierce County Superior Court to provide more oversight of the TPD.

These proposals are listed in order from most to least preferable, and most protective to least protective. Judicial remedies are prioritized over legisla­tive remedies because this issue is in the unique purview of the judiciary to “say what the law is” under the Constitution.76 Even though Congress has the ability to legislate on Constitutional issues, Congress is unable, absent a Constitutional Amendment, to legislate a Constitutional protection into existence. The Courts, in interpreting the Constitution, set the floor for what constitutes a “search” and proper process under the Fourth Amendment. Moreover, if the remedy were legislative, it could be altered or simply erased by another statute because there are no stabilizing judicial principles such as stare decisis or judicial restraint. Judicial remedies are also preferred because the exclusionary rule is a judicially created prophylactic rule that the courts could (and should) apply to the use of pen registers and Stingrays.

Even if Congress attempted to limit the admissibility of evidence obtained from Stingrays that enters the courtroom, the Fourth Amendment and rules of evidence are not its area of expertise. This is evidenced by the fact that the Federal Rules of Evidence are first crafted by advisory committees consisting of legal practitioners, law professors, and judges before they are passed, following minor edits, by Congress.77 A s s uch, judicial r emedies would streamline the process and be consistent with the application of prophylactic rules.

Finally, judicial resolution is the best route here because the Supreme Court recently granted certiorari review over Carpenter v. United States, which again gives the Court the opportunity to examine the issue of whether law enforcement’s use of cellular information, such as the numbers dialed and where a call originated and terminated, is protected by the Fourth Amend­ment and requires a probable cause search warrant.78

In Carpenter, the defendant, Timothy Carpenter, was charged with con­spiring and participating in a string of armed robberies. He was arrested after one of the other suspects was captured, confessed, and turned over his phone to the FBI so they could review his call logs.79 Once it was determined that Carpenter’s phone was called during the time of the robberies and al­ways within a two-mile radius, he became a suspect and was later charged and convicted for aiding and abetting.80 While the Sixth Circuit’s decision affirmed Carpenter’s conviction under the reasoning of Smith, the dissent stated the decision was out of line with Fourth Amendment tracking juris­prudence, as law enforcement used Carpenter’s cell phone to physically track his movements despite a previous Supreme Court decision stating that GPS tracking of a suspect without a warrant violated the Fourth Amendment.81

In light of recent Supreme Court decisions on technology and the Fourth Amendment, and the fact that the attorneys for Carpenter are likely to echo Justice Marshall’s dissent in Smith by arguing that cell phones have become inextricably intertwined with individuals’ personal affairs, Carpenter gives the Supreme Court the opportunity to essentially reconsider Smith v. Mary­land. This decision has the ability to rewrite Fourth Amendment jurispru­dence in the area of pen registers in a matter of a few months.


It is not the judiciary’s job to make law enforcement’s job easier. It is, however, the job of the judiciary to jealously guard the rights enshrined in the Constitution for the citizens of the United States. The decision of Smith v. Maryland, that a pen register does not constitute a “search,” is flawed. This holding was ignorant as to the evolving standards of technological capabilities and it incorrectly applied Katz v. United States. Even if Smith were allowed to stand, using Stingray technology as a “pen register” not only constitutes an illegal “search,” but encourages a culture of secrecy surrounding law enforcement methods that, in turn, results in the public’s decreased trust in law enforcement. Furthermore, this secrecy creates a scenario where those who are supposed to be checking the power of law enforcement, judges and legislators, are being deceived as to what their authorizations are being used for.

The United States can survive violent criminals or another terror attack. What the United States cannot survive is a judiciary that, in the name of “order” and “security,” sacrifices its role as a check on the political branches of government; its role as the defender of the United States Constitution.



  1. Jennifer Valentino-Devries, How ‘Stingray’ Devices Work, Wall St. J. (Sept. 21, 2011), https://blogs. NNIFER+VALENTINO-DEVRIES.
  2. Smith v. Maryland, 442 U.S. 735 (1979).
  3. Katz v. United States, 389 U.S. 347 (1967).
  4. See Marbury v. Madison, 5 U.S. 137 (1803).
  5. U.S. Const. amend. IV.
  6. See Olmstead v. United States, 277 U.S. 438 (1928).
  7. Id.
  8. Katz, 389 U.S. 347.
  9. Id. at 360 (J. Harlan, concurring).
  10. Smith, 442 U.S. at 737; Katz, 389 U.S. at 361.
  11. Beck v. Ohio, 379 U.S. 89, 91 (1964)
  12. Id.
  13. Carroll v. United States, 267 U.S. 132 (1925).
  14. Dumbra v. United States, 268 U.S. 435 (1925).
  15. See Weeks v. United States, 232 U.S. 383 (1914).
  16. Id.
  17. Id.
  18. Elkins v. United States, 364 U.S. 206 (1960); Nardone v. United States, 308 U.S. 338 (1939) (where J. Frankfurter described the rule as prohibiting evidence obtained as “fruit of the poisonous tree”).
  19. See generally United States v. Calandra, 414 U.S. 338 (1974); United States v. Leon, 468 U.S. 897 (1984); Nix v. Williams, 467 U.S. 431 (1984).
  20. Smith, 442 U.S. at 744.
  21. Id.
  22. Id.
  23. Id.
  24. Id. at 743.
  25. Id.
  26. Smith, 442 U.S. at 744.
  27. Id.
  28. See Ellen Nakashima, Apple Vows to Resist FBI Demand to Crack iPhone Linked to San Bernardino Attacks, Wash. Post (Feb. 17, 2016), https://www.washingtonpost. com/world/national-security/us-wants-apple-to-help-unlock-iphone-used-by-san-bernardino-shooter/2016/02/16/69b903ee-d4d9-11e5-9823-02b905009f99_story. html?utm_term=.52007a397fad.
  29. Smith, 442 U.S. at 747 (J. Stewart, dissenting).
  30. Id. at 748 (J. Marshall, dissenting).
  31. Id. (J. Marshall, dissenting).
  32. See Nakashima, supra note 28.
  33. See David Shepardson, Major Internet Providers Say Will Not Sell Customer Browsing Histories, Reuters (Mar. 31, 2017, 12:42 PM), us-usa-fcc-data-idUSKBN1722D6.
  34. Valentino-Devries, supra note 1.
  35. Id.
  36. See Kyllo v. United States, 533 U.S. 27 (2001).
  37. United States v. Jones, 565 U.S. 400 (2012).
  38. Riley v. California, 134 S. Ct. 2473 (U.S. 2014).
  39. Stephanie Pell & Christopher Soghoian, A Lot More Than a Pen Register, and Less Than a Wiretap: What The Stingray Teaches Us About How Congress Should Approach the Reform of Law Enforcement Surveillance Authorities, 16 Yale J.L& Tech. 134 (2014).
  40. Id.
  41. Id.
  42. Id.
  43. Id.
  44. Id.
  45. Candice Rudd, Tacoma Hit with $50,000 Fine Plus Legal Fees Over Stingray Nondisclosure Agreement, The News Tribune (Mar. 3, 2017, 6:08 PM), http://www.
  46. Id.
  47. Id.
  48. Id.
  49. Id.
  50. Kate Martin, New Law Requires Warrants for Stingray Use, The News Tribune (May 11, 2015, 3:55 PM),­ticle26288260.html [hereinafter Martin, New Law].
  51. Kate Martin, Documents: Tacoma Police Using Surveillance Device to Sweep Up Cellphone Data, The News Tribune (Aug. 26, 2014, 3:56 PM), http://www.thenews­ [hereinafter Martin, Documents].
  52. Id.
  53. Id.
  54. Id.
  55. Id.
  56. Id.
  57. Id.
  58. Adam Lynn, Tacoma Police Change How They Seek Permission to Use Cellphone Tracker, The News Tribune (Nov. 15, 2014, 12:00 AM) http://www.thenewstribune. com/news/local/crime/article25894096.html.
  59. Id.
  60. Id.
  61. Martin, Documents, supra note 51.
  62. Lynn, supra note 58.
  63. Id.
  64. Id.
  65. Id.
  66. Id.
  67. Id.
  68. Martin, Documents, supra note 51.
  69. Martin, New Law, supra note 50.
  70. Id.
  71. Ryan Gallagher, FBI Files Unlock History Behind Clandestine Cellphone Tracking Tool, Slate (Feb. 15, 2013, 2:34 PM), stingray_imsi_catcher_fbi_files_unlock_history_behind_cellphone_tracking.html.
  72. Patrick E. Corbett, The Fourth Amendment and Cell Site Location Information: What Should We Do While We Wait for the Supremes?, 8 Fed Cts. L. Rev. 215, 227 (2015).
  73. See Kyllo v. United States, 533 U.S. 27 (2001).
  74. See Riley v. California, 134 S. Ct. 2473 (U.S. 2014).
  75. See United States v. Jones, 565 U.S. 400 (2012).
  76. See Marbury v. Madison, 5 U.S. 137 (1803).
  77. Josh Camson, History of the Federal Rules of Evidence, AmericanBar Association, (last visited Oct. 22, 2017).
  78. United States v. Carpenter, 819 F.3d 880 (6th Cir. 2016).
  79. Id.
  80. Id.
  81. Id.; see Kyllo v. United States, 533 U.S. 27 (2001).