State v. Bobby L. Tate

2014 WI 89

SUPREME COURT OF WISCONSIN
CASE NO.: 2012AP336-CR
COMPLETE TITLE: State of Wisconsin,
Plaintiff-Respondent,
v.
Bobby L. Tate,
Defendant-Appellant-Petitioner.

REVIEW OF A DECISION OF THE COURT OF APPEALS
Reported at 345 Wis. 2d 847, 826 N.W.2d 123
(Ct. App. 2012 – Unpublished)

OPINION FILED: July 24, 2014
SUBMITTED ON BRIEFS:
ORAL ARGUMENT: October 3, 2013

SOURCE OF APPEAL:
COURT: Circuit
COUNTY: Milwaukee
JUDGE: Cimpl

JUSTICES:
CONCURRED:
DISSENTED: ABRAHAMSON, C.J., BRADLEY, J., (joins Parts I-
IV) dissent. (Opinion filed.)
NOT PARTICIPATING:

ATTORNEYS:
For the defendant-appellant-petitioner, there were briefs
by Byron Lichstein, law student Michael J. King, and Frank J.
Remington Center, University of Wisconsin Law School, and oral
argument by Byron Lichstein.

For the plaintiff-respondent, the cause was argued by
Jeffrey J. Kassel, assistant attorney general, with whom on the
brief was J.B. Van Hollen, attorney general.
 2014 WI 89
NOTICE
This opinion is subject to further
editing and modification. The final
version will appear in the bound
volume of the official reports.
No. 2012AP336-CR
(L.C. No. 2009CF2842)

STATE OF WISCONSIN : IN SUPREME COURT

State of Wisconsin,

Plaintiff-Respondent,
FILED
v. JUL 24, 2014

Bobby L. Tate, Diane M. Fremgen
Clerk of Supreme Court

Defendant-Appellant-Petitioner.

REVIEW of a decision of the Court of Appeals. Affirmed.

¶1 PATIENCE DRAKE ROGGENSACK, J. We review an

unpublished decision of the court of appeals1 affirming the

decision of the Milwaukee County Circuit Court2 denying defendant

Bobby L. Tate's motion to suppress evidence that law enforcement

obtained by tracking Tate's cell phone using cell site location

information ("cell site information") and a stingray. Before

tracking Tate's cell phone, law enforcement obtained an order

approving the use of a pen register/trap and trace device and

1
State v. Tate, No. 2012AP336-CR, unpublished slip op.
(WiS. Ct. App. Dec. 27, 2012).
2
The Honorable Dennis R. Cimpl presided.
 No. 2012AP336-CR

the release of certain subscriber information, such as cell

tower activity and location information. Tate argues that law

enforcement violated his right against unreasonable searches

under both the Fourth Amendment of the United States

Constitution and Article I, Section 11 of the Wisconsin

Constitution and that the order authorizing the tracking of his

cell phone required statutory authority, which it lacked.

¶2 In evaluating Tate's argument, we assume without

deciding that: (1) law enforcement's activities constituted a

search within the meaning of the Fourth Amendment and Article I,

Section 11; and (2) because the tracking led law enforcement to

discover Tate's location within his mother's home, a warrant was

needed. We then conclude that the search was reasonable because

it was executed pursuant to an order3 that met the Fourth

Amendment's and Article I, Section 11's requirements. See State

v. Higginbotham, 162 Wis. 2d 978, 989, 471 N.W.2d 24 (1991). We

also conclude that specific statutory authorization was not

necessary for Milwaukee County Circuit Court Judge Jeffrey

Wagner to issue the order that authorized the procedures used to

track Tate's cell phone because the order was supported by

probable cause. Nonetheless, the order did comply with the

3
The document Milwaukee County Circuit Court Judge Jeffrey
Wagner signed was captioned "Order." It is this document that
functioned as a warrant for our constitutional considerations
and as a criminal subpoena in regard to the information obtained
from the cell service provider. State v. Sveum, 2010 WI 92,
¶¶20, 39, 328 Wis. 2d 369, 787 N.W.2d 317 (a document entitled
"order" can constitute a warrant for Fourth Amendment purposes).

2
 No. 2012AP336-CR

spirit of Wis. Stat. § 968.12 and Wis. Stat. § 968.135 (2009-

10),4 the search warrant and criminal subpoena statutes, which

express legislative choices about procedures to employ for

warrants and criminal subpoenas.5 Accordingly, we affirm the

decision of the court of appeals.

I. BACKGROUND

¶3 On the evening of June 9, 2009, law enforcement

responded to a homicide outside of Mother's Foods Market/Magic

Cell Phones at 2879 N. 16th Street in Milwaukee. Upon arrival,

officers found a victim lying between the curb and the sidewalk

with a fatal gunshot wound to the head. A second victim was

taken to the hospital to receive treatment for a gunshot wound

to his left ankle.

¶4 Witnesses described the shooter as a black male

wearing a striped polo shirt. Footage from Mother's Foods'

surveillance camera showed a person matching the suspect's

description purchase a prepaid cellular phone inside the store,

leave the store and shoot the victim in the back of the head.

The clerk who sold the phone to the suspect told police that the

4
All subsequent references to the Wisconsin Statutes are to
the 2009-10 version unless otherwise indicated.
5
2013 Wisconsin Act 375, enacted April 23, 2014, effective
April 24, 2014, sets out the actions to be taken when an
investigative or law enforcement officer seeks to obtain cell
phone tracking information. See Wis. Stat. § 968.373 and Wis.
Stat. § 968.375(4)(c) (2013-14). These statutes were not in
effect when Tate's cell phone was tracked.

3
 No. 2012AP336-CR

suspect identified himself to her as "Bobby" and said that he

had just gotten out of prison that day.

¶5 Mother's Foods provided police with information about

the phone the suspect purchased, including the telephone number

assigned to the phone. Detective Patrick Pajot used two

internet databases to confirm that US Cellular was the service

provider for that phone.

¶6 Upon these facts, which Detective Pajot described in a

sworn affidavit, Assistant District Attorney Grant Huebner

applied for an order approving the following: (1) installation

and use of a trap and trace device or process; (2) installation

and use of a pen register device or process; and (3) the release

of subscriber information, including cell tower activity and

location and global positioning system (GPS) information that

could identify the physical location of the target phone.6

6
The order approved:

(1) . . . the installation and use of a trap and
trace device or process[;]

(2) . . . the installation and use of a pen
register device/process or Dialed Number Recorder
(DNR) on a cellular telephone line, a designated
Electronic Serial Number (ESN), an International
Mobile Subscriber Identifier (IMSI), an International
Mobile Equipment Identifier (IMEI), or other cellular
lines of a particular subscriber[; and]

(3) . . . the release of subscriber information,
incoming and outgoing call detail, cellular tower
activity, cellular tower location, text header
information, cellular toll information and cellular
telephone global positioning system (GPS) location
information, if available, and authorizing the
4
 No. 2012AP336-CR

¶7 Officer Brian Brosseau of the Milwaukee County's

Intelligence Fusion Division testified at the suppression

hearing about the technology officers ultimately used to locate

the suspect's phone, which included cell site information7 and a

stingray.8 Cell site information allows law enforcement to

locate a cell phone by triangulation. The Collection and Use of

identification of the physical location of a target
cellular phone.
7
With the older style analog cellular phones and
digital mobile phones that are not GPS capable the
cellular network provider can determine where the
phone is to within a hundred feet or so using
"triangulation" because at any one time, the phone is
usually able to communicate with more than one of the
aerial arrays provided by the phone network. The cell
towers are typically 6 to 12 miles apart (less in
cities) and a phone is usually within range of at
least three of them. By comparing the signal strength
and time lag for the phone's carrier signal to reach
at each tower, the network provider can triangulate
the phone's approximate position.

L. Scott Harrell, Locating Mobile Phones Through Pinging and
Triangulation, Pursuit (July 1, 2008),
http://pursuitmag.com/locating-mobile-phones-through-pinging-
and-triangulation (last visited July 3, 2014).
8
A stingray is an electronic device that mimics the signal
from a cellphone tower, which causes the cell phone to send a
responding signal. If the stingray is within the cell phone's
signal range, the stingray measures signals from the phone, and
based on the cell phone's signal strength, the stingray can
provide an initial general location of the phone. By collecting
the cell phone's signals from several locations, the stingray
can develop the location of the phone quite precisely. Jennifer
Valentino-DeVries, "Stingray" Phone Tracker Fuels Constitutional
Clash, Wall Street Journal, Sept. 22, 2011, available at
http://online.wsj.com/news/articles/SB10001424053111904194604576
583112723197574 (last visited July 3, 2014).

5
 No. 2012AP336-CR

Location Info. for Commercial Purposes: J. Hearing Before the

Subcomm. on Commerce, Trade, and Consumer Prot. and Subcomm. on

Commc'ns, Tech., and the Internet of the H. Comm. on Energy and

Commerce, 111th Cong. 34, 36 (2010) (statement of Lorrie Faith

Cranor, Assoc. Professor of Computer Science and of Engineering

& Public Policy, Carnegie Mellon University). Any time a cell

phone is turned on, it is searching for a signal and, in the

process, identifying itself with the nearest cell tower every

seven seconds. ECPA Reform and the Revolution in Location Based
Tech. and Servs.: Hearing Before the Subcomm. on the

Constitution, Civil Rights, and Civil Liberties of the H. Comm.

on the Judiciary, 111th Cong. 17, 20-21 (2010) (statement of

Matt Blaze, Associate Professor, University of Pennsylvania); In

Re Application for Pen Register & Trap/Trace Device with Cell

Cite Location Auth. 396 F. Supp. 2d 747, 750 (S.D. Tex. 2005).

Cell service providers can "collect data from th[e]se contacts,

which allows [them] to locate cell phones on a real-time basis

and to reconstruct a phone's movement from recorded data."

State v. Earls, 70 A.3d 630, 632 (N.J. 2013).

¶8 It is not clear from the record exactly how law

enforcement used cell site information in the present case. We

do not know whether US Cellular or law enforcement triangulated

the signals from the target phone. We also do not know whether

US Cellular regularly collects this information, or if it did so

solely at law enforcement's request. Officer Brosseau explained

only that, "[w]e were receiving information with the cell tower

information, what that cell tower is currently on" and that, as
6
 No. 2012AP336-CR

a general matter, "the cell phone provider . . . send[s] us data

regarding a certain number . . . [pen] register9 information on

that particular phone number." He stated that the phone signal

"was bouncing between three different cell phone towers on three

different sectors which if you were to map it out were to give

you an angle or an area of probability of where you believe the

suspect would be . . . at that time."

¶9 After law enforcement received cell site information

from US Cellular, officers used a stingray to further narrow

down the phone's location. The stingray, a device that mimicked

a cell tower, allowed officers to locate the phone based on

signal strength. See Jennifer Valentino-DeVries, "Stingray"
Phone Tracker Fuels Constitutional Clash, Wall Street Journal,

Sept. 22, 2011, available at

http://online.wsj.com/news/articles/SB10001424053111904194604576

583112723197574 (last visited July 3, 2014). Officer Brosseau

explained that law enforcement's stingray is a "directional

antenna mounted on our vehicle which will respond only to that

electronic serial number of which we're looking for and it will

9
Wisconsin Stat. § 968.27(13) defines a pen register as "a
device that records or decodes electronic or other impulses that
identify the numbers dialed or otherwise transmitted on the
telephone line to which the device is attached." Officer
Brosseau explained that a pen register "records all of the
towers and sectors" on which a cell phone is operating. In
other words, in order to provide cell site information to
police, a cellular provider must have "its own pen register and
send the results to law enforcement." Steven B. Toeniskoetter,
Preventing a Modern Panopticon: Law Enforcement Acquisition of
Real-Time Cellular Tracking Data, 13 Rich. J.L. & Tech. 16, ¶87
(2007).
7
 No. 2012AP336-CR

give [us] an arrow, if you will, pointing to the direction and

with the strength tell [us] how close [we] are to that

particular electronic." Using the stingray, officers "could

tell [the target phone] was on the . . . south and east side" of

a particular apartment building on the 5700 block of West

Hampton Avenue.

¶10 At that point, officers entered the apartment building

and began knocking on the doors of individual apartments on the

southeast side of the building. After searching the apartments

of three or four residents and not locating what they were

looking for, officers knocked on the door of the defendant's

mother, Doris Cobb.

¶11 Officers entered10 Cobb's apartment and asked her if
Bobby was there. She told them he was, and pointed toward his

bedroom. Officers found the defendant sleeping in the back

bedroom, along with a striped polo shirt and a tennis shoe that

appeared to have blood on it and the cell phone. They arrested

Tate for first-degree intentional homicide.

10
Witnesses gave conflicting testimony about whether Cobb
granted law enforcement access to her apartment. Law
enforcement officers said that she did, but Cobb testified that
she did not, explaining that she "just opened the door, [and]
they just came in" and that since "they were police, I thought
they [were] supposed to come in." Transcript of Motion Hearing
at 67, 70. Tate does not raise this issue, so we assume Cobb
granted permission to enter her apartment. A.O. Smith Corp. v.
Allstate Ins. Cos., 222 Wis. 2d 475, 492, 588 N.W.2d 285 (Ct.
App. 1998) ("in order for a party to have an issue considered by
this court, it must be raised and argued within its brief").

8
 No. 2012AP336-CR

¶12 Tate moved to suppress the evidence seized pursuant to

the order to track his cell phone, including the items seized

from his mother's apartment, statements from people in the

apartment building, and statements Tate made after his arrest.

Tate argued that law enforcement needed a search warrant to

track Tate's phone and that Judge Wagner's order was not the

equivalent of a search warrant.

¶13 The circuit court denied the motion to suppress,

concluding that Judge Wagner's order was sufficient to allow law

enforcement to track Tate's phone to the apartment building and

that Cobb consented to a search of the apartment. Tate pled no

contest to first-degree reckless homicide, but appealed the

suppression decision. The court of appeals affirmed the

conviction, concluding that Judge Wagner had a "substantial

basis for finding probable cause to issue the order to locate

Tate's cell phone." We agree and now affirm the decision of the

court of appeals.

II. DISCUSSION

A. Standard of Review

¶14 We independently review "whether police conduct

violated the constitutional guarantee against unreasonable

searches," which presents a question of constitutional fact.

State v. Arias, 2008 WI 84, ¶11, 311 Wis. 2d 358, 752 N.W.2d 748

(quoting State v. Griffith, 2000 WI 72, ¶23, 236 Wis. 2d 48, 613

N.W.2d 72). However, we review a warrant-issuing magistrate's

determination of whether the affidavit in support of the order

was sufficient to show probable cause with "great deference."
9
 No. 2012AP336-CR

Higginbotham, 162 Wis. 2d at 989. A warrant-issuing

magistrate's determination of probable cause will be affirmed

unless the facts asserted in support of the warrant are clearly

insufficient to support probable cause. Id. We also

independently determine whether "the language of a court order

satisfies the requisite constitutional requirements of a

warrant." State v. Sveum, 2010 WI 92, ¶17, 328 Wis. 2d 369, 787

N.W.2d 317.

¶15 And finally, in addressing Tate's argument that the

circuit court lacked statutory authority to issue the order, we

interpret and apply Wis. Stat. § 968.12 and Wis. Stat.

§ 968.135. Statutory interpretation and application present

questions of law for our independent review. Richards v. Badger
Mut. Ins. Co., 2008 WI 52, ¶14, 309 Wis. 2d 541, 749 N.W.2d 581.

In so doing, we benefit from the discussions of both the court

of appeals and the circuit court, just as we do with other

questions of law. Marder v. Bd. of Regents of the Univ. of Wis.

Sys., 2005 WI 159, ¶19, 286 Wis. 2d 252, 706 N.W.2d 110.

B. Search

¶16 Tate compares cell phone tracking technology to the

GPS tracking device that we examined in State v. Brereton, 2013

WI 17, ¶34, 345 Wis. 2d 563, 826 N.W.2d 369. He contends that

tracking a cell phone through cell site information and a

stingray involves a similar "usurpation of an individual's

property" and therefore constitutes a search. Id.

¶17 In Brereton, we concluded that the law enforcement

officers who placed a GPS device on a defendant's car and
10
 No. 2012AP336-CR

monitored his movements in order to conduct surveillance

"invad[ed] privacy interests long afforded, and undoubtedly

entitled to, Fourth Amendment protection" when they used his

property without his permission. Id. (quoting United States v.

Jones, 132 S. Ct. 945, 954 (2012) (Sotomayor, J., concurring)).

¶18 When the United States Supreme Court analyzed a

similar physical placement of a GPS device on a defendant's car,

it did so in terms of trespass. Jones, 132 S. Ct. at 947. In
Brereton, we noted that tracking through the use of a GPS device

attached to a defendant's car may have constituted a search

"even in the absence of a trespass." Brereton, 345 Wis. 2d 563,

¶34 (quoting Jones, 132 S. Ct. at 954-55 (Sotomayor, J.,

concurring)).

¶19 We reiterated that to determine whether a search

occurs when law enforcement uses tracking technology to which a

physical trespass on a defendant's property does not apply, we

apply the test set forth in Katz v. United States, 389 U.S. 347

(1967), which asks whether "the government violates a subjective

expectation of privacy that society recognizes as reasonable."

Brereton, 345 Wis. 2d 563, ¶34 (quoting Jones, 132 S. Ct. at

954-55) (further citation omitted).

¶20 The issue of whether tracking through cell site

information and a stingray "violates a subjective expectation of

privacy that society recognizes as reasonable" is not before us

because the State has conceded, and therefore has not briefed,

whether such tracking is a search within the meaning of the

11
 No. 2012AP336-CR

Fourth Amendment.11 Still, we briefly take stock of the

doctrines that inform our search analysis and note several

challenges in applying them to the technology at issue in this

case.

¶21 First, analyzing whether surveillance using cell site

information constitutes a search under Katz can become quite

circular. That is, "the same technological advances that have

made possible nontrespassory surveillance techniques . . . also

affect the Katz test by shaping the evolution of societal
privacy expectations." Jones, 132 S. Ct. at 955 (Sotomayor, J.,

concurring); Jones, 132 S. Ct. at 963 (Alito, J., concurring)

("phone-location-tracking services [that] are offered as

'social' tools . . . shape the average person's expectations

about the privacy of his or her daily movements").

¶22 Second, it is unclear how the notion that a purchaser

accepts goods as they come to him, including whether the goods

11
In Riley v. California, 573 U.S. __, 134 S. Ct. 2473
(2014), the United States Supreme Court held that an officer may
not "search digital information on a cell phone seized from an
individual who has been arrested" without prior judicial
authorization. Id. at 2480. The Court explained that an
individual retains a reasonable expectation of privacy in the
contents of a cell phone because a search of that phone could
reveal a panoply of personal information through which "[t]he
sum of an individual's private life can be reconstructed." Id.
at 2489. The Court discussed location information as one type,
among many, of information a cell phone could contain. It did
not address, however, "the question whether the collection or
inspection of aggregated digital information amounts to a search
under other circumstances." Id. at 2489 n.1. Additionally,
Riley's applicability to the case before us is diminished
because law enforcement obtained judicial authorization before
tracking Tate's phone.

12
 No. 2012AP336-CR

can be traced electronically in real time, should impact such an

analysis. Jones, 132 S. Ct. at 952; see United States v. Karo,

468 U.S. 705, 712-13 (1984) (defendant was not entitled to

object to law enforcement's tracking of a can of ether because

the tracking device, a beeper, was placed in the can before it

belonged to the defendant).

¶23 Further complicating the matter is the location of the

cell phone. For example, when law enforcement contemplates

tracking a cell phone, they may not know whether the phone is

located in a private residence, which stands at the "very core"

of the Fourth Amendment, or is traveling down a public highway,

in which case a defendant may have no expectation of privacy in

his movements. Kyllo v. United States, 533 U.S. 27, 31 (2001)
(quoting Silverman v. United States, 365 U.S. 505, 511 (1961));

United States v. Knotts, 460 U.S. 276, 281 (1983) ("A person

traveling in an automobile on public thoroughfares has no

reasonable expectation of privacy in his movements from one

place to another."); Sveum, 328 Wis. 2d 369, ¶79 (Ziegler, J.,

concurring) ("installing and monitoring a GPS tracking device on

a vehicle in a public area does not constitute a search or

seizure within the meaning of the Fourth Amendment").

¶24 Finally, even movements in public areas can reveal

highly personal information such as "familial, political,

professional, religious, and sexual associations," which if

monitored too closely, may "chill[] associational and expressive

freedoms." Jones, 132 S. Ct. 955-56 (Sotomayor, J.,

concurring.)
13
 No. 2012AP336-CR

¶25 At a minimum, it seems that to successfully argue that

one has a reasonable expectation of privacy in cell site

information requires a reexamination of "the premise that an

individual has no reasonable expectation of privacy in

information voluntarily disclosed to third parties." Id. at 957

(Sotomayor, J., concurring).12 Cases in which the United States

Supreme Court asked not what information a hypothetical third

person could obtain but rather, what a person generally expects

from third parties show that third party doctrine, even in its

current state, has permutations.13

12
The United States Supreme Court developed the third party
disclosure through a series of "false friend" cases that held
that "one typically retains no federal constitutional reasonable
expectation of privacy in information conveyed to a third
party," but the "doctrine is not absolute." ABA Standards for
Criminal Justice, Law Enforcement Access to Third Party Records
at 6 & n.16, 7 (3d ed. 2013).
13
See Florida v. Jardines, 133 S. Ct. 1409, 1416 (2013)
("introducing a trained police dog to explore the area around
the home in hopes of discovering incriminating evidence"
constitutes a search because it is not part of a "customary
invitation" to attempt entry); City of Ontario, Cal. v. Quon,
560 U.S. 746, 760-65 (2010) (concluding that city's review of
employee's text messages sent on a pager provided by the city
was not unreasonable and therefore did not violate the Fourth
Amendment); Kyllo v. United States, 533 U.S. 27, 34 (2001)
(thermal imaging of a home constituted a search because the
sense-enhancing technology was not "in general public use");
Bond v. United States, 529 U.S. 334, 335, 338-39 (2000)
("physical manipulation of a bus passenger's carry-on luggage"
constituted a search because a passenger does not expect fellow
bus passengers or bus employees to "feel the bag in an
exploratory manner," even if he may expect them to move it, and
therefore handle the bag).

14
 No. 2012AP336-CR

¶26 We are mindful that courts should "proceed with care

when considering the whole concept of privacy expectations in

communications made on electronic equipment" and that "[t]he

judiciary risks error by elaborating too fully on the Fourth

Amendment implications of emerging technology before its role in

society has become clear." City of Ontario, Cal. v. Quon, 560

U.S. 746, 759 (2010). For that reason and because the parties

do not dispute that a search occurred, we assume, without

deciding, that tracking a cell phone using cell site information

and a stingray constitutes a search that has constitutional

implications.

C. Reasonableness of the Search

¶27 The Fourth Amendment of the United States

Constitution14 and Article I, Section 11 of the Wisconsin

Constitution15 protect persons from "unreasonable searches" and

14
The Fourth Amendment of the United States Constitution
provides:

The right of the people to be secure in their
persons, houses, papers, and effects, against
unreasonable searches and seizures, shall not be
violated, and no Warrants shall issue, but upon
probable cause, supported by Oath or affirmation, and
particularly describing the place to be searched, and
the persons or things to be seized.
15
Article I, Section 11 of the Wisconsin Constitution
provides:

The right of the people to be secure in their
persons, houses, papers, and effects against
unreasonable searches and seizures shall not be
violated; and no warrant shall issue but upon probable
cause, supported by oath or affirmation, and
15
 No. 2012AP336-CR

establish the manner in which warrants shall issue. State v.

Henderson, 2001 WI 97, ¶17 & n.4, 245 Wis. 2d 345, 629 N.W.2d

613.16 "Searches made without warrants issued pursuant to the

requirements of the warrant clause are presumed to be

unconstitutional." Id., ¶19.

¶28 As to searches made pursuant to a warrant, they pass

constitutional muster if they comply with the three requirements

of the Warrant Clause of the Fourth Amendment:

(1) prior authorization by a neutral, detached
magistrate; (2) a demonstration upon oath or
affirmation that there is probable cause to believe
that evidence sought will aid in a particular
conviction for a particular offense; and (3) a
particularized description of the place to be searched
and items to be seized.
Sveum, 328 Wis. 2d 369, ¶20.
¶29 The first requirement "interposes[s] the impartial

judgment of a [neutral] officer between the citizen and the

police and also between the citizen and the prosecutor, so that

an individual may be secure from an improper search." Id., ¶21

(quoting State ex rel. White v. Simpson, 28 Wis. 2d 590, 598,
137 N.W.2d 391 (1965)).

particularly describing the place to be searched and
the persons or things to be seized.
16
We generally have interpreted the state constitution to
provide "the same constitutional guarantees as the Supreme Court
has accorded through its interpretation of the Fourth
Amendment." State v. Kramer, 2009 WI 14, ¶18, 315 Wis. 2d 414,
759 N.W.2d 598; see also Sveum, 328 Wis. 2d 369, ¶18 n.7. We
follow that tradition here.

16
 No. 2012AP336-CR

¶30 The second requirement provides that the person

seeking a warrant demonstrate upon oath or affirmation

sufficient facts to support probable cause to believe that "the

evidence sought will aid in a particular apprehension or

conviction for a particular offense." Henderson, 245 Wis. 2d

345, ¶19 (quoting Dalia v. United States, 441 U.S. 238, 255

(1979)) (internal quotation marks omitted).17 Finally, the third

requirement focuses on the place to be searched and requires

that it be identified with particularity, in addition to the

items to be seized. Id. In the event that a search warrant
does not comply with these requirements, we may invoke the

exclusionary rule if no exception to the warrant requirements

applies. Sveum, 328 Wis. 2d 369, ¶31 & n.8.

D. Application

¶31 Tate argues that law enforcement officers performed an

illegal search when they tracked his cell phone using cell site

information and a stingray because the tracking constituted a

search that violated the Fourth Amendment of the United States

Constitution and Article I, Section 1 of the Wisconsin

Constitution and because Judge Wagner "lacked statutory

authority to issue an order authorizing police to track Tate's

phone in real time." This latter contention implies that

17
Tate urges us to disregard the "apprehension" portion of
this formulation, arguing that Warden v. Hayden, 387 U.S. 294,
307 (1967), the original source of this language, is properly
regarded as dicta. Because we conclude that the phone had
evidentiary value, we do not reach this argument.

17
 No. 2012AP336-CR

statutory authority is necessary to the lawful issuance of a

warrant.

¶32 In regard to the latter contention, Tate also asserts

that the statutes Judge Wagner cited, Wis. Stat. § 968.35, Wis.

Stat. § 968.36, 18 U.S.C. §§ 2703, 2711, 3117, 3125, and 3127,

did not grant the court the power to authorize law enforcement

18
 No. 2012AP336-CR

to obtain location data through cell site information or a

stingray, either individually or collectively.18

1. Constitutional sufficiency

¶33 To be constitutionally sufficient, a warrant must be

based on probable cause and be reasonable both in its issuance

and in its execution. Henderson, 245 Wis. 2d 345, ¶¶18–20. The

warrant we review was based on the affidavit of Detective Pajot,

18
Tate cites federal cases holding that this mosaic of
authority is insufficient to allow law enforcement to track a
cell phone using cell site information. But, the State points
out, in those cases the government sought to obtain cell site
information not upon a showing of probable cause, but upon a
lower statutory showing. See In re Application of the United
States for an Order Authorizing the Disclosure of Prospective
Cell Site Info., 412 F. Supp. 2d 947, 949 n.1 (E.D. Wis. 2006)
(the issue "of whether a search warrant issued in accordance
with the provisions of Rule 41 would support issuance of the
requested order (if the appropriate showing were made) is not
before" the court); In re Application for Pen Register &
Trap/Trace Device with Cell Site Location Auth., 396 F. Supp. 2d
747, 765 (S.D. Tex. 2005) ("Denial of the government's request
for prospective cell site data in this instance should have no
dire consequences for law enforcement. This type of surveillance
is unquestionably available upon a traditional probable cause
showing under Rule 41."); In re Application of the United States
for an Order (1) Authorizing the Use of a Pen Register & a Trap
& Trace Device and (2) Authorizing Release of Subscriber Info.
and/or Cell Site Info., 396 F. Supp. 2d 294, 300 (E.D.N.Y. 2005)
("disclosure of cell site information turns a mobile telephone
into a 'tracking device' and therefore such disclosure may not
be authorized without a showing of probable cause"); In re
Application of the United States for an Order Authorizing the
Installation & Use of a Pen Register & a Caller Identification
Sys. on Tele. Nos. [] & [] and the Prod. of Real Time Cell Cite
Info., 402 F. Supp. 2d 597, 605 (D. Md. 2005) ("When the
government seeks to acquire and use real time cell site
information to identify the location and movement of a phone and
its possessor in real time, the court will issue a warrant upon
a sworn affidavit demonstrating probable cause to believe the
information will yield evidence of a crime.").

19
 No. 2012AP336-CR

who described sufficient facts to support probable cause to

believe that the cell phone site information law enforcement

sought would aid in "a particular apprehension or conviction for

a particular offense." Id., ¶19 (quoting Warden v. Hayden, 387

U.S. 294, 307 (1967)) (internal quotation marks omitted).

¶34 Judge Wagner was told that a surveillance video made

at the time of a homicide captured a person wearing a

distinctive shirt, who identified himself to a store clerk as

"Bobby" when he purchased a cell phone. He also was told that,

moments later, surveillance video captured a person matching

that physical description shooting two people outside the store.

Finding the cell phone the suspect purchased could be probative

that the person in possession of the phone was the shooter.

Tate has not established that the facts before the circuit court

were clearly insufficient to support a determination of probable

cause. See id.; Higginbotham, 162 Wis. 2d at 989.
¶35 In regard to Tate's complaint that Detective Pajot,

Assistant District Attorney Huebner and Judge Wagner did not

address why the cell phone constituted evidence of a crime,

neither the Fourth Amendment nor our decisions require the

person seeking a warrant to explain why a particular object or

information constitutes evidence. Higginbotham, 162 Wis. 2d at

989.

¶36 Starting with Assistant District Attorney Huebner's

application for the order and the order itself, the standard is

whether the warrant-issuing magistrate is "apprised of

sufficient facts to excite an honest belief in a reasonable mind
20
 No. 2012AP336-CR

that the objects sought are linked with the commission of a

crime, and that the objects sought will be found in the place

to be searched." State v. Starke, 81 Wis. 2d 399, 408, 260

N.W.2d 739 (1978). In keeping with this standard, our decisions

have focused on the sufficiency of the evidence, not the legal

arguments of the applicant or the reasoning of the magistrate.

E.g., State v. Kerr, 181 Wis. 2d 372, 380-81, 511 N.W.2d 586

(1994) (although the supporting affidavit contained "minimal

factual basis to support probable cause," we upheld a

determination of probable cause based on the "veracity and basis

of knowledge of persons supplying . . . information").

¶37 As to Detective Pajot's affidavit, we have described

the responsibilities of an affiant seeking a warrant as follows:

[A]ffidavits for search warrants[] . . . must be
tested and interpreted by magistrates and courts in a
commonsense and realistic fashion. They are normally
drafted by nonlawyers in the midst and haste of a
criminal investigation. Technical requirements of
elaborate specificity once exacted under common law
pleadings have no proper place in this area. A
grudging or negative attitude by reviewing courts
toward warrants will tend to discourage police
officers from submitting their evidence to a judicial
officer before acting. . . . Recital of some of the
underlying circumstances in the affidavit is essential
if the magistrate is to perform his detached function
and not serve merely as a rubber stamp for the police.
However, where these circumstances are detailed, where
reason for crediting the source of the information is
given, and when a magistrate has found probable cause,
the courts should not invalidate the warrant by
interpreting the affidavit in a hypertechnical, rather
than a commonsense, manner.
Higginbotham, 162 Wis. 2d at 991-92 (quoting Starke, 81 Wis. 2d
at 410) (further citation omitted).

21
 No. 2012AP336-CR

¶38 Although we do not require an affiant to provide legal

theories, we do require a narration of sufficient facts and a

statement upon what basis such a narration is made. However, if

an affiant seeks a warrant based solely on his or her own legal

conclusions, the magistrate cannot find probable cause. Id. at

992. Having concluded that Judge Wagner had a sufficient

factual basis for finding probable cause, we turn to Tate's

particularity argument.19

¶39 Tate argues that the order fails the Fourth

Amendment's particularity requirement because it does not

specify a particular location where evidence will be found.

When it had failed to timely obtain a warrant for the monitoring

of a beeper in a home, the government made a similar argument in

Karo: "it would be impossible to describe the 'place' to be
searched, because the location of the place is precisely what is

sought to be discovered." Karo, 468 U.S. at 718. The Supreme

Court was not impressed with that logic and concluded that the

government could describe the object into which the beeper would

be placed and the circumstances that led the government to want

to install the beeper. Id.

¶40 Tate's similar argument that the particularity

requirement of the Fourth Amendment's warrant clause was not met

fails for two reasons. First, both the United States Supreme

Court and this court have upheld searches involving tracking

19
Tate does not dispute that Judge Wagner was a neutral
magistrate, so we do not address that warrant requirement.

22
 No. 2012AP336-CR

devices despite the impossibility of describing the exact place

to be searched by a traditional description, such as a street

address. Id.; Brereton, 345 Wis. 2d 563, ¶¶52-54; Sveum, 328

Wis. 2d 369, ¶52. Second, we disagree with Tate's argument that

since there was no physical installation of the tracking device

on Tate's property in this case, as there was in Karo, Brereton,

and Sveum, the order does not satisfy the particularity

requirement.

¶41 In Sveum, we explained that "[i]n order to satisfy the
particularity requirement, the warrant must enable the searcher

to reasonably ascertain and identify the things which are

authorized to be seized." Sveum, 328 Wis. 2d 369, ¶27 (quoting

State v. Noll, 116 Wis. 2d 443, 450-51, 343 N.W.2d 391 (1984)).

While a description of the object into which the tracking device

was to be placed was a factor in satisfying the particularity

requirement in Sveum, there is no reason why another way of

identifying a cell phone, such as by its electronic serial

number, cannot serve the same function as physically placing the

tracking device on Tate's property. Accordingly, we conclude

that the employment of the electronic serial number for Tate's

phone satisfies the particularity requirement because that

number permits a particularized collection of cell site

information for only one cell phone. Therefore, applying great

deference to Judge Wagner's probable cause determination, we

conclude that the warrant passes constitutional muster.

2. Statutory sufficiency

23
 No. 2012AP336-CR

¶42 No specific statutory authority is necessary to the

issuance of a valid warrant for cell site information. See id.,

¶¶69-72 (explaining that the failure to comply with all of the

statutory provisions relating to warrants did not affect the

validity of the warrant). However, even though statutory

authorization was not necessary in order to issue the warrant,

because the legislature has enacted general criteria about the

procedures to employ with regard to issuing warrants, we examine

relevant statutes.

¶43 Wisconsin Stat. § 968.10(3) authorizes searches

pursuant to a valid warrant, and Wis. Stat. § 968.12(1)

provides:

A search warrant is an order signed by a judge
directing a law enforcement officer to conduct a
search of a designated person, a designated object or
a designated place for the purpose of seizing
designated property or kinds of property. A judge
shall issue a search warrant if probable cause is
shown.
The probable cause that § 968.12(1) speaks to is comparable to

probable cause under the Fourth Amendment. See id., ¶44; see
also Bergman v. State, 189 Wis. 615, 617-18, 208 N.W. 470

(1926) (quoting State v. Blumenstein, 186 Wis. 428, 430, 202

N.W. 684 (1925) (overruled on other grounds)) (§ 968.12's

predecessor, Wis. Stat. § 4839, "must be construed in accordance

with the constitutional requirements upon the subject of

searches and seizures").

¶44 Wisconsin Stat. § 968.12(1) requires a judge to issue

a warrant upon a showing of probable cause, and we conclude that

24
 No. 2012AP336-CR

Judge Wagner's order was supported by probable cause. We also

conclude that law enforcement's use of a stingray to locate

Tate's cell phone was reasonable. Law enforcement's use of cell

site information requires additional discussion because

§ 968.12(1) must be read in concert with Wis. Stat. § 968.13(2)

and Wis. Stat. § 968.135 in order to have a more complete

statutory picture when law enforcement seeks a warrant to obtain

cell site information.

¶45 Tate explained in his brief that "[w]hen a cell phone

identifies itself to a cell site, a log of location information

is created and stored in a carrier's database."20 While the

record in this case does not show exactly what form this log of

location information takes, we think it is safe to assume that

it would come within Wis. Stat. § 968.13(2)'s broad definition

of documents, which "includes, but is not limited to, books,

papers, records, recordings, tapes, photographs, films or

computer or electronic data."21

20
We do not know whether US Cellular maintained this log as
a matter of routine or whether it installed a pen register at
law enforcement's request in order to collect cell site
information for law enforcement. See Toeniskoetter, supra
note 9 (cellular service providers obtain cell site information
by installing their own pen register). This distinction could
matter if law enforcement had not obtained prior judicial
authorization for the tracking. See Wis. Stat. § 968.34(2)(a)
(prohibiting the use of a pen register without prior judicial
authorization, subject to certain exceptions, one of which
relates to a cellular service provider's "operation, maintenance
and testing of a wire or electronic communication service").
21
See also In re Application of the United States for
Historical Cell Site Data, 724 F.3d 600, 615 (5th Cir. 2013)
("[c]ell site data are business records").

25
 No. 2012AP336-CR

¶46 Search warrants issued under Wis. Stat. § 968.12(1)

may not authorize the seizure of documents, Wis. Stat.

§ 968.13(1)(c), unless they are "under the control of a person

who is reasonably suspected to be concerned in the commission of

that crime," § 968.13(1)(d). According to Officer Brosseau's

testimony, law enforcement officers tracked Tate's cell phone

using cell site information obtained from a cellular service

provider. Therefore, the documents sought were in the hands of

a third party; they were not "under the control of a person who

is reasonably suspected to be concerned in the commission of

that crime."

¶47 When law enforcement wants to compel a third party to

turn over documents, it can proceed to obtain an order to that

effect, pursuant to Wis. Stat. § 968.135. Section 968.135

provides that "a court shall issue a subpoena requiring the

production of documents, as specified in s. 968.13(2)." This is

done "[u]pon the request of the attorney general or a district

attorney and upon a showing of probable cause."22 Id.

22
Because Wis. Stat. § 968.135 "does not limit or affect
any other subpoena authority provided by law," we note that
§ 968.135 does not restrict the authority to issue a subpoena
under Wis. Stat. § 968.375. Section 968.375 describes
situations in which a judge may issue a subpoena or warrant to
obtain records or information from an "electronic communication
service or remote computing service provider." It does not
limit a judge's powers under the more general subpoena statute,
§ 968.135. We do not decide whether § 968.375 provides an
additional source of authority for Judge Wagner's order because
no party has addressed § 968.375.

26
 No. 2012AP336-CR

¶48 We have held that failure to make a probable cause

determination, when one is required in order to obtain

particular documents, may deprive a defendant of the safeguards

to which he is entitled. State v. Popenhagen, 2008 WI 55, ¶4,

309 Wis. 2d 601, 749 N.W.2d 611. However, Popenhagen has no

application here.

¶49 In Popenhagen, law enforcement officers and the

district attorney obtained a criminal defendant's bank records

pursuant to a subpoena issued under Wis. Stat. § 805.07, the

civil subpoena statute. Because they sought to obtain the

record as part of a criminal investigation, they should have

proceeded under the criminal subpoena statute, Wis. Stat.

§ 968.135, which

strictly limits a court's issuance of a subpoena for
the production of documents. Only the attorney
general or a district attorney may request a subpoena
for the production of documents. The request must be
ruled upon by the circuit court before the subpoena is
issued. The circuit court may issue a subpoena for
documents only upon a showing of probable cause.23

23
The legislature chose to require probable cause for a
subpoena issued under Wis. Stat. § 968.135. We note, however,
that we do not decide whether the Fourth Amendment comes into
play when obtaining cell site information in part because any
electronic documents have necessarily been shared with a third
party. See In re Application of the United States for
Historical Cell Site Data, 724 F.3d at 614-15 (rejecting a
constitutional challenge to the Stored Communication Act's
"specific and articulable facts" standard for disclosure of
historical cell site information because a cell phone user
"voluntarily conveys . . . cell site data" to the phone company
"each time he makes a call").

27
 No. 2012AP336-CR

Id., ¶53. The officers in Popenhagen did not present an

affidavit showing probable cause to the subpoena-issuing judges

and those judges did not make the determination of probable

cause that § 968.135 requires. Id., ¶7.

¶50 Unlike the defendant in Popenhagen, Tate was not

deprived of Wis. Stat. § 968.135's safeguards. Judge Wagner

issued the order upon the request of a district attorney. He

determined that the probable cause standard had been met based

on Detective Pajot's sworn affidavit. We reject the argument

that the court's citation to statutes that may not have been the

best choices is reversible error because Judge Wagner's analysis

was consistent with the legal standard Wis. Stat. § 968.12 and

Wis. Stat. § 968.135 required. Accordingly, we conclude that

Tate's substantial rights were not prejudiced.

III. CONCLUSION

¶51 In evaluating Tate's argument, we assume without

deciding that: (1) law enforcement's activities constituted a

search within the meaning of the Fourth Amendment and Article I,

Section 11; and (2) because the tracking led law enforcement to

discover Tate's location within his mother's home, a warrant was

needed. We then conclude that the search was reasonable because

it was executed pursuant to a warrant that met the Fourth

Amendment's and Article I, Section 11's requirements. See

Higginbotham, 162 Wis. 2d at 989. We also conclude that

specific statutory authorization was not necessary for Judge

Wagner to issue the order that authorized the procedures used to

track Tate's cell phone because the order was supported by
28
 No. 2012AP336-CR

probable cause. Nonetheless, the order did comply with the

spirit of Wis. Stat. § 968.12 and Wis. Stat. § 968.135, which

express legislative choices about procedures to employ for

warrants and criminal subpoenas. Accordingly, we affirm the

decision of the court of appeals.

By the Court.—The decision of the court of appeals is

affirmed.

29
 No. 2012AP336-CR.ssa

¶52 SHIRLEY S. ABRAHAMSON, C.J. (dissenting). "Advances

in technology offer great benefits to society in many areas. At

the same time, they can pose significant risks to individual

privacy rights."1 The proliferation of cell phones and their

location tracking capabilities exemplify the risks to privacy

rights posed by technological advancement.

¶53 The criminal cases State v. Tate2 and State v. Subdiaz-

Osorio3 raise the question whether individuals have a

constitutional right of privacy in their cell phone location

data. In other words, do the United States4 and Wisconsin

Constitutions5 permit law enforcement to access a person's cell

phone location data without a warrant?

1
State v. Earls, 70 A.3d 630, 631-32 (N.J. 2013).
2
State v. Tate, 2014 WI 89, ___ Wis. 2d ___, ___
N.W.2d ___.
3
State v. Subdiaz-Osorio, 2014 WI 87, ___ Wis. 2d ___, ___
N.W.2d ___.
4
The Fourth Amendment to the United States Constitution
provides:

The right of the people to be secure in their persons,
houses, papers, and effects, against unreasonable
searches and seizures, shall not be violated, and no
Warrants shall issue, but upon probable cause,
supported by Oath or affirmation, and particularly
describing the place to be searched, and the persons
or things to be seized.
5
Article 1, Section 11 of the Wisconsin Constitution
provides:

The right of the people to be secure in their persons,
houses, papers, and effects against unreasonable
searches and seizures shall not be violated; and no
warrant shall issue but upon probable cause, supported
by oath or affirmation, and particularly describing
1
 No. 2012AP336-CR.ssa

¶54 Cell phones are a "pervasive and insistent part of

daily life . . . ."6 The vast majority of Americans own cell

phones; the Pew Research Center has reported that, as of May

2013, 91% of American adults have a cell phone and 56% have a

smartphone.7 Cell phones are literally and figuratively attached

to their users' persons, such that "the proverbial visitor from

Mars might conclude they were an important feature of human

anatomy."8 Unlike land-line phones, people generally carry cell

phones with them at all times——at home, in the car, at work, and

at play.

¶55 Cell phones can thus serve as powerful tracking

devices that can pinpoint our movements with remarkable

accuracy. They can isolate in time and place our presence at

shops, doctors' offices, religious services, Alcoholics

Anonymous meetings, AIDS treatment centers, abortion clinics,

political events, theaters, bookstores, and restaurants, and

the place to be searched and the persons or things to
be seized.
6
Riley v. California, 134 S. Ct. 2473, 2484 (2014).
7
Earls, 70 A.3d at 638.
8
Riley, 134 S. Ct. at 2484. The Riley Court additionally
noted that "nearly three-quarters of smart phone users report
being within five feet of their phones most of the time, with
12% admitting that they even use their phones in the shower."
Id. at 2490.

2
 No. 2012AP336-CR.ssa

identify with whom the user of the cell phone associates.9
Cellular service providers have records of the geographic

location of almost every American at almost every moment of the

day and night.10 Accessing this information reveals intimate

details about a person and intrudes on the constitutional right

of association. The United States Supreme Court characterizes

location data as "qualitatively different" from physical

records, noting that location data can "reconstruct someone's

specific movements down to the minute, not only around town but

also within a particular building."11 The more precise the

tracking, the greater the privacy concerns.

¶56 Cell phone location data can also be a formidable

instrument in fighting crime. In both Tate and Subdiaz-Osorio,

the law enforcement officers were performing their important

public safety duties by investigating violent crimes. Both

criminal suspects were apprehended in relatively short order

through law enforcement use of cell phone location data.

¶57 The officers in Tate and Subdiaz-Osorio had to deal
with the thorny issues raised by seeking access to individuals'

9
See Earls, 70 A.3d at 632. See also Riley, 134 S. Ct. at
2489 ("Cell phones differ in both a quantitative and a
qualitative sense from other objects that might be kept on an
arrestee's person. . . . [Cell phones] could just as easily be
called cameras, video players, rolodexes, calendars, tape
recorders, libraries, diaries, albums, televisions, maps, or
newspapers.").
10
See Noam Cohen, It's Tracking Your Every Move and You May
Not Even Know, N.Y. Times, Mar. 26, 2011, at A1.
11
Riley, 134 S. Ct. at 2490 (citing United States v. Jones,
132 S. Ct. 945 (2012) (Sotomayor, J., concurring)).

3
 No. 2012AP336-CR.ssa

cell phone location data. Law enforcement is the first word in

interpreting constitutional requirements; the courts are the

last.

¶58 It is this court's responsibility to evaluate a

potential search "by assessing, on the one hand, the degree to

which it intrudes upon an individual's privacy and, on the

other, the degree to which it is needed for the promotion of

legitimate governmental interests." Wyoming v. Houghton, 526
U.S. 295, 300 (1999).

¶59 This court owes it to law enforcement, lawyers,

litigants, circuit courts, the court of appeals, and the public

at large to provide clarity about when a search has occurred

regarding cell phone location data and what procedures must be

undertaken by the government to render such searches

constitutional.12 A clear set of rules will protect privacy

interests and also give guidance to individuals evaluating these

interests.

¶60 Rather than dance around the issue of whether
government access to cell phone location data in the instant

cases is a search within the meaning of the Constitutions, I

propose that the court address it head-on. Government access to

cell phone location data raises novel legal questions of great

importance for the privacy rights of the public in an emerging

12
"[W]e promote clarity in the law of search and seizure
and provide straightforward guidelines to governmental officers
who must apply our holdings." State v. Williams, 2012 WI 59,
¶25, 341 Wis. 2d 191, 814 N.W.2d 460.

4
 No. 2012AP336-CR.ssa

area of technology——exactly the type of questions appropriate

for resolution pursuant to this court's law-developing function.

¶61 I conclude that government access to cell phone

location data in the instant cases, which involves invasive

surveillance of an individual's movements, is a search within

the meaning of the Constitutions.13 To read the Constitutions

more narrowly is to ignore the vital role that the cell phone

has come to play in private communications, to paraphrase the

United States Supreme Court in Katz v. United States, 389 U.S.

347, 352 (1967).14

¶62 People do not buy cell phones to have them serve as

government tracking devices. They do not expect the government

to track them by using location information the government gets

from cell phones.15 People have a subjective expectation of

privacy in cell phone location data that society is prepared to

13
Justices Ann Walsh Bradley and N. Patrick Crooks agree
with this conclusion.
14
"To read the Constitution more narrowly is to ignore the
vital role that the public telephone has come to play in private
communication." Katz v. United States, 389 U.S. 347, 352
(1967).
15
See, e.g., United States v. Davis, ___ F.3d ___, 2014 WL
2599917, at *9 (11th Cir. 2014) ("[I]t is unlikely that cell
phone customers are aware that their cell phone providers
collect and store historical location information.") (quoting In
re Application of U.S. for an Order Directing a Provider of
Elec. Commc'n Serv. To Disclose Records to Gov't, 620 F.3d 304,
317 (3d Cir. 2010)); Earls, 70 A. 3d at 632.

5
 No. 2012AP336-CR.ssa

recognize as reasonable. Thus, absent a warrant, such a search

is per se unreasonable.16
¶63 If the State does not have a warrant, the State can

access cell phone location data only if the State can

demonstrate one of the narrowly drawn exceptions to the warrant

requirement. In both Tate and Subdiaz-Osorio, law enforcement

officers could have accessed cell phone location data with a

properly authorized warrant that complied with existing relevant

statutes.17 They did not.

¶64 I address the balance between privacy interests and

law enforcement interests as presented by Tate and Subdiaz-

Osorio.18 These two cases address substantially similar issues

regarding government access to cell phone location data but pose

distinct fact patterns.

¶65 Neither the Tate majority opinion nor Justice

Prosser's lead opinion in Subdiaz-Osorio decides whether the

government access in question constituted a search within the

meaning of the United States and Wisconsin Constitutions. Both
opinions assume that a search occurred.

¶66 Despite the insistence of the Tate majority opinion

and Justice Prosser's lead opinion in Subdiaz-Osorio that they

16
State v. Sanders, 2008 WI 85, ¶27, 311 Wis. 2d 257, 752
N.W.2d 713; State v. Payano-Roman, 2006 WI 47, ¶30, 290
Wis. 2d 380, 714 N.W.2d 548.
17
I refer to the court order issued in Tate as a "warrant,"
as does the Tate majority opinion. The applicable statute
refers to a court issuing a "subpoena" requiring the production
of documents. Wis. Stat. § 968.135.
18
"Privacy comes at a cost." Riley, 134 S. Ct. at 2493.

6
 No. 2012AP336-CR.ssa

merely assume, without deciding, that the government access was

a search in each case,19 both opinions address the search issue
as they elaborate on cases and principles underlying their

assumption that a search occurred.

¶67 The Tate majority opinion and Justice Prosser's lead

opinion in Subdiaz-Osorio refer to and draw guidance from the

same Wisconsin and United States Supreme Court cases, including

the recently mandated Riley v. California, 573 U.S. ___, 134 S.

Ct. 2473 (2014).20

¶68 The Tate majority opinion and Justice Prosser's lead

opinion announce principles of law that overlap and to an extent

19
Tate, majority op., ¶¶2, 26; Subdiaz-Osorio, 2014 WI 87,
¶¶9, 70 (Prosser, J., lead op.). But see Subdiaz-Osorio, 2014
WI 87, ¶132 (Roggensack, J., concurring) (accusing Justice
Prosser's lead opinion in Subdiaz-Osorio of not merely assuming
the issue of the reasonable expectation of privacy but in effect
deciding the issue).
20
See Riley, 134 S. Ct. 2473 (cited in Tate, majority op.,
¶20 n.11; in Subdiaz-Osorio, 2014 WI 87, ¶47 n.23 (Prosser, J.,
lead op.)); Katz, 389 U.S. at 353 (cited in Tate, majority op.,
¶¶19-21; in Subdiaz-Osorio, 2014 WI 87, ¶¶51-52, 65-66 (Prosser,
J., lead op.); in Subdiaz-Osorio, 2014 WI 87, ¶3 (Roggensack,
J., concurring)); Jones, 132 S. Ct. 945 (2012) (cited in Tate,
majority op., ¶¶17-25; in Subdiaz-Osorio, 2014 WI 87, ¶¶43, 48,
51 (Prosser, J., lead op.); in Subdiaz-Osorio, 2014 WI 87, ¶135
(Roggensack, J., concurring); State v. Brereton, 2013 WI 17, 345
Wis. 2d 563, 826 N.W.2d 369 (cited in Tate, majority op., ¶¶16-
18, 40; in Subdiaz-Osorio, 2014 WI 87, ¶¶38, 49 (Prosser, J.,
lead op.); State v. Sveum, 2010 WI 92, 328 Wis. 2d 369, 787
N.W.2d 317 (cited in Tate, majority op., ¶¶14, 23, 28, 30, 40-
43; in Subdiaz-Osorio, 2014 WI 87, ¶49 (Prosser, J., lead op.)).

7
 No. 2012AP336-CR.ssa

conflict with each other.21 The two opinions, as well as the

separate writings in Subdiaz-Osorio of Justices Ann Walsh

Bradley, N. Patrick Crooks, and Patience Drake Roggensack, must

thus be read together carefully to understand the court's

position on the constitutionality of law enforcement access to a

person's cell phone location data.22

¶69 To address the overlapping issues raised by these two

cases, I organize my dissenting opinions as follows. Each

heading number corresponds to the relevant subdivision of each

dissent.

¶70 In my dissent in Tate, I address the following main

points:

Part I. The police access to the defendant's cell phone

location data, an issue in both Tate and Subdiaz-Osorio,

was a search within the meaning of the Constitutions.23

21
See Subdiaz-Osorio, 2014 WI 87, ¶¶131-132 (Roggensack,
J., concurring) (criticizing Justice Prosser's lead opinion in
Subdiaz-Osorio for "elaborate[ing] too fully on the Fourth
Amendment implications of emerging technology before its role in
society has become clear"); Subdiaz-Osorio, ¶50 (Prosser, J.,
lead op.) (noting that Tate shares similarities with Subdiaz-
Osorio even though it is ultimately decided on other issues).
22
In footnotes 23 through 30, I consolidate and summarize
the position of each opinion in Tate and Subdiaz-Osorio
regarding particular topics.
23
For discussions of whether a search existed, see:

Tate, majority op., ¶26: Assumes, without deciding, that
there was a search.

Subdiaz-Osorio, 2014 WI 87, ¶9 (Prosser, J., lead op.):
Assumes, without deciding, that there was a search but
hints strongly that a search existed.

8
 No. 2012AP336-CR.ssa

Part II. The search existed as a trespass.24
Part III. The search existed as an invasion of an

individual's reasonable expectation of privacy.

A. The subjective expectation of privacy was not

undermined by:

1. The cell phone contract;25 or

Subdiaz-Osorio, 2014 WI 87, ¶89 (Bradley, J., concurring),
¶116 (Crooks, J., concurring): Determine that there was a
search.

Subdiaz-Osorio, 2014 WI 87, ¶¶131-137 (Roggensack, J.,
concurring): Criticizes Justice Prosser's lead opinion for
elaborating too fully on right to privacy in cell phone
location data.

Subdiaz-Osorio, 2014 WI 87, ¶139-143 (Ziegler, J.,
concurring): Joining Justice Roggensack's concurrence, and
requesting additional briefing on whether a search existed.

Tate, Chief Justice Abrahamson's dissent, ¶61: Yes, access
to cell phone location data is a search. See also Subdiaz-
Osorio, 2014 WI 87, ¶155 (Abrahamson, C.J., dissenting).
24
For discussions of whether a trespass existed, see:

Tate, majority op., ¶¶18-20: Discusses trespass but refers
to the search only as "nontrespassory."

Subdiaz-Osorio, 2014 WI 87, ¶¶48-50 (Prosser, J., lead
op.): Trespass analysis would be "unnatural."

Tate, Chief Justice Abrahamson's dissent, ¶¶101-102: State
does not disclose how information was obtained; appears to
be a trespass. See also Subdiaz-Osorio, 2014 WI 87, ¶168
(Abrahamson, C.J., dissenting).
25
For discussions of whether the cell phone contract
created consent to access the cell phone location data, see:

Tate, majority op., ¶22: Defendant might consent through
purchase of cell phone.

9
 No. 2012AP336-CR.ssa

2. The third-party doctrine.26
B. Society recognizes a reasonable expectation of

privacy in cell phone location data.27

Subdiaz-Osorio, 2014 WI 87, ¶¶53-63 (Prosser, J., lead
op.): Consent through cell phone purchase contract was
invalid.

Subdiaz-Osorio, 2014 WI 87, ¶¶133-135 (Roggensack, J.,
concurring): Questions J. Prosser's lead opinion regarding
contract.

Tate, Chief Justice Abrahamson's dissent, ¶116-121:
Adhesion contract will not be enforced to waive
constitutional rights. See also Subdiaz-Osorio, 2014 WI
87, ¶168 (Abrahamson, C.J., dissenting).
26
For discussions of the impact of third-party doctrine,
see:

Tate, majority op., ¶¶24-25: Third-party doctrine may need
reevaluation.

Subdiaz-Osorio, 2014 WI 87, ¶134-135 (Roggensack, J.,
concurring): Questions whether expectation of privacy
exists in third-party records.

Tate, Chief Justice Abrahamson's dissent, ¶¶122-135: Third-
party doctrine in inapplicable to cell phone location data.
27
For discussions of whether society recognizes a
reasonable expectation of privacy, see:

Tate, majority op., ¶¶2, 16-25: Expectation of privacy may
be lower for cell phone location, especially in a public
area; expectation of privacy was dependent on the cell
phone's location in a home.

Subdiaz-Osorio, 2014 WI 87, ¶¶65-68 (Prosser, J., lead
op.): Public expects privacy in cell phone location data
and worries about invasion of privacy.

Subdiaz-Osorio, 2014 WI 87, ¶134-135 (Roggensack, J.,
concurring): Questions whether expectation of privacy
exists in third-party records.

10
 No. 2012AP336-CR.ssa

Part IV. Wisconsin Stat. § 968.135, the statute setting
forth the requirements for a subpoena of documents, should

have been followed——it was not in either Tate or in

Subdiaz-Osorio.28

¶71 In my dissent in Subdiaz-Osorio, I address two main

points:

Part V. The State failed to meet its burden to demonstrate

the existence of exigent circumstances;29 and

Tate, Chief Justice Abrahamson's dissent, ¶¶136-149: Case
law, public policy, and Wisconsin legislation point to
society recognizing reasonable expectation of privacy in
cell phone location data. See also Subdiaz-Osorio, 2014 WI
87, ¶168 (Abrahamson, C.J., dissenting).
28
For discussions of the warrant requirement, see:

Tate, majority op., ¶¶33-50: Warrant did not comply with
Wis. Stat. § 968.135, subpoena for third-party information.
Non-statutory warrant met constitutional requirements.
Non-statutory warrants met "spirit" of warrant statutes.

Subdiaz-Osorio, 2014 WI 87, ¶5 n.2 (Prosser, J., lead op.):
No warrant at issue, but warrants must meet Fourth
Amendment and statutory requirements.

Subdiaz-Osorio, 2014 WI 87, ¶89 (Bradley, J., concurring):
A warrant was needed and the State's warrant failed to
comply in either case.

Subdiaz-Osorio, 2014 WI 87, ¶118 (Crooks, J., concurring):
A warrant was needed but the good-faith exception applied.

Tate, Chief Justice Abrahamson's dissent, ¶¶150-163: State
fails to comply with statutory warrant requirements.
Warrant was invalid. See also Subdiaz-Osorio, 2014 WI 87,
¶168 (Abrahamson, C.J., dissenting).
29
For discussions of exigent circumstances, see:

Tate: Exigent circumstances not at issue.

11
 No. 2012AP336-CR.ssa

Part VI. The defendant invoked his Miranda right to an
attorney at his interrogation.30

¶72 My discussion in Parts I-IV of my Tate dissent is

relevant to Subdiaz-Osorio, and I incorporate Parts I-IV of my

Subdiaz-Osorio, 2014 WI 87, ¶¶69-81 (Prosser, J., lead
op.): Exigent circumstances exception to warrant
requirement was satisfied.

Subdiaz-Osorio, 2014 WI 87, ¶89 (Bradley, J., concurring):
there were no exigent circumstances.

Subdiaz-Osorio, 2014 WI 87, ¶118 (Crooks, J., concurring):
there were no exigent circumstances.

Subdiaz-Osorio, 2014 WI 87, ¶130 (Roggensack, J.,
concurring): Law enforcement acted reasonably under the
Fourth Amendment due to exigent circumstances.

Subdiaz-Osorio, 2014 WI 87, ¶¶169-208 (Abrahamson, C.J.,
dissenting): State fails to meet its burden to show exigent
circumstances.
30
For discussions of the Miranda right to an attorney, see:

Tate: Miranda rights not at issue.

Subdiaz-Osorio, 2014 WI 87, ¶¶82-87 (Prosser, J., lead
op.): Defendant failed to invoke unequivocally right to an
attorney.

Subdiaz-Osorio, 2014 WI 87, ¶89 (Bradley, J., concurring):
Defendant successfully invoked Miranda right.

Subdiaz-Osorio 2014 WI 87, ¶109 (Crooks, J., concurring);
id., ¶130 (Roggensack, J., concurring): Defendant failed to
invoke unequivocally right to an attorney.

Subdiaz-Osorio, 2014 WI 87, ¶¶209-219 (Abrahamson, C.J.,
dissenting): A reasonable person would understand Subdiaz-
Osorio to have invoked his Miranda right.

12
 No. 2012AP336-CR.ssa

Tate dissent into my Subdiaz-Osorio dissent without repeating
them in full.31

¶73 Accordingly, I dissent in both cases.

I

¶74 The majority opinion in Tate and Justice Prosser's

lead opinion in Subdiaz-Osorio do not answer the core question

presented: Does law enforcement's access to an individual's

cell phone location data in the present cases constitute a

31
The two cases raise numerous additional issues that I do
not address, including the applicability of federal statutes,
the good-faith exception, and the proper standard for reviewing
and remedying an illegal search of cell phone location data.

Justice Crooks' concurrence in Subdiaz-Osorio asserts that
an illegal warrantless search occurred, Subdiaz-Osorio, 2014 WI
87, ¶¶125-128 (Crooks, J., concurring), but that the good-faith
exception applies, and that the evidence should not have been
excluded. As I explain in Parts I-IV, our state's case law
already set forth the need for a warrant and the statutes
provide procedures for obtaining a warrant. These rules of law
existed at the time that the officers initiated the search in
the instant cases.

I am unconvinced that the usual harmless-error analysis is
the proper approach in Tate and Subdiaz-Osorio. See Subdiaz-
Osorio, 2014 WI 87, ¶¶97-105 (Bradley, J., concurring) (applying
harmless-error analysis in Subdiaz-Osorio). When illegally
obtained cell phone location data forms the entire basis for the
apprehension and arrest of the defendant, rather than evidence
of the crime, the usual harmless-error analysis appears to be a
poor fit.

13
 No. 2012AP336-CR.ssa

search under the Wisconsin and United States Constitutions? I

would answer this important question in the affirmative.32
¶75 The various opinions in Tate and Subdiaz-Osorio

disagree about the impact of the recent United States Supreme

Court case Riley v. California, 573 U.S. ___, 134 S. Ct. 2473

(2014). Riley held that law enforcement must obtain a warrant

before searching the contents of a cell phone in a search

incident to arrest. The Riley opinion extolled the strong

privacy interests of individuals in electronic data stored,

accessed, or maintained on cell phones.

32
In Earls, 70 A.3d 630, although the New Jersey Supreme
Court recognized the difficulty of calculating exactly what
level of privacy society expects in its technological products,
the court declared that individuals have a reasonable
expectation of privacy in their cell phone location data, and
therefore the police must obtain a search warrant before
accessing that information.

[O]ur focus belongs on the obvious: cell phones are
not meant to serve as tracking devices to locate their
owners wherever they may be. People buy cell phones
to communicate with others, to use the Internet, and
for a growing number of other reasons. But no one
buys a cell phone to share detailed information about
their whereabouts with the police.

Earls, 70 A.3d at 643.

Similarly, the Massachusetts Supreme Judicial Court has
held that an individual's privacy interest in cell phone
location data is one that society accepts as reasonable, and
that law enforcement's request for cell phone location data from
an individual's cell phone provider is a search requiring Fourth
Amendment protections. Commonwealth v. Augustine, 4 N.E.3d 846
(Mass. 2014).

Recently, the federal Eleventh Circuit Court of Appeals has
also held that cell phone location data is within society's
reasonable expectation of privacy. See United States v. Davis,
___ F.3d ___, 2014 WL 2599917 (11th Cir. 2014).

14
 No. 2012AP336-CR.ssa

¶76 The majority opinion in Tate and Justice Prosser's
lead opinion in Subdiaz-Osorio distinguish Riley by stating that

Riley does not address the instant question: whether a

defendant has a reasonable expectation of privacy in location

data. They relegate Riley to a footnote.33 Conversely, Justice

Crooks' concurrence in Subdiaz-Osorio relies heavily on Riley

for its statements on the privacy interests of individuals in

cell phone data to determine that police access of cell phone

location data constitutes a search.34

¶77 The issue in the instant case of whether access of

cell phone location data constitutes a search was not before the

Court in Riley. I do not rely on Riley's holding regarding

search incident to arrest in my analysis. The language in Riley

is, however, instructive in the instant case. I draw from the

teachings of Fourth Amendment case law of both Wisconsin and the

United States regarding privacy interests to analyze whether a

search occurred within the meanings of the Wisconsin and United

States Constitutions in the present case. I analyze and apply
the case law using both the trespass and the reasonable

expectation of privacy doctrines applicable to the Fourth

Amendment.

¶78 The case law of our state already provides us with

ample basis to determine that the law enforcement access in Tate

33
Tate, majority op., ¶20 n.11; Subdiaz-Osorio, 2014 WI 87,
¶47 n.23 (Prosser, J., lead op.).
34
Subdiaz-Osorio, 2014 WI 87, ¶109 (Crooks, J.,
concurring).

15
 No. 2012AP336-CR.ssa

and Subdiaz-Osorio constituted searches within the meaning of
the Constitutions.

¶79 In State v. Brereton,35 the court forcefully declared

that law enforcement access and monitoring of an individual's

location data through the use of a Global Positioning Systems

(GPS) device on a motor vehicle is a search within the meaning

of the Constitutions.36 If the collection of location data via a

GPS device attached to a motor vehicle is a search, then

government acquisition of more invasive cell phone location data

is a search. Cell phone location data is often more

sophisticated and precise, and cell phones' ubiquity raises

greater privacy concerns than GPS tracking of a motor vehicle.

¶80 The Brereton court explained that "warrantless GPS

tracking would constitute a search even in the absence of a

trespass, [because] a Fourth Amendment search occurs when the

government violates a subjective expectation of privacy that

society recognizes as reasonable."37

¶81 If there was any doubt that the Brereton court held
that the GPS tracking of location data was a search within the

meaning of the Constitutions, the Brereton court added:

35
State v. Brereton, 2013 WI 17, 345 Wis. 2d 563, 826
N.W.2d 369, cert. denied, 134 S. Ct. 93 (U.S. 2013).
36
Although the court is not bound by a party's concession
of law, both the State's and defendant's briefs in Tate assert
that Brereton, 345 Wis. 2d 563, makes clear that the GPS
tracking was a search within the meaning of the Constitutions
and required a warrant. Brief of Plaintiff-Respondent at 14-15;
Brief and Appendix of Defendant-Appellant-Petitioner at 24-25.
37
Brereton, 345 Wis. 2d 563, ¶34 (internal quotation marks
omitted).

16
 No. 2012AP336-CR.ssa

The privacy interest at issue . . . , where the
government has utilized [the defendant's] property to
apply GPS technology to monitor his movements, is
government usurpation of an individual's property "for
the purpose of conducting surveillance on him, thereby
invading privacy interests long afforded, and
undoubtedly entitled to, Fourth Amendment
protection."38
¶82 Brereton relied on United States v. Jones, 565 U.S.
___, 132 S. Ct. 945 (2012), in which the United States Supreme

Court unanimously determined that the attachment of a GPS device

to a motor vehicle was a search under the United States

Constitution, with three separate opinions reaching their

conclusions by relying on different Fourth Amendment doctrines.

¶83 Jones is instructive in the instant case. The Jones

majority opinion, authored by Justice Scalia and joined by four

other Justices, held that the attachment of the GPS device

constituted a trespass onto the defendant's property.39 Justice

Alito, in a concurrence joined by three other Justices, asserted

that extensive recording of an individual's location "impinges

on expectations of privacy."40 Justice Sotomayor joined the

majority opinion relying on trespass law but wrote a separate

concurrence, asserting that although trespass doctrine settled

the case in Jones, even short-term monitoring of an individual's

38
Id. (citing Jones, 132 S. Ct. at 954).

The Brereton court clearly stated numerous times that "the
use of a GPS device constituted a search . . . ," Brereton, 345
Wis. 2d 563, ¶43, and that "the privacy interest implicated by
the GPS search required judicial authorization," id., ¶44.
39
Jones, 132 S. Ct. at 949-54.
40
Jones, 132 S. Ct. at 964 (Alito, J., concurring in the
judgment).

17
 No. 2012AP336-CR.ssa

location implicates the right to privacy.41 Thus, five Justices

viewed the GPS device and its tracking of an individual's

location as impinging on expectations of privacy.

¶84 Our case law also recognizes that government access to

data stored on cell phones42 and personal computers43 constitutes

a search within the meaning of the Constitutions. Thus, even if

law enforcement officers have consent to search an area, "an

independent analysis" must be performed to determine whether a

personal electronic device can also be searched.44

¶85 I agree with the statements in Justice Prosser's lead

opinion in Subdiaz-Osorio on the importance of privacy and its

relationship to our modern, interconnected, electronic-device-

mediated world. "Privacy is a pillar of freedom."45 "[P]rivacy

serves more than the individual; it is an integral component of

a well-ordered society."46 "[P]rivacy must not become a legal

fiction."47 "[E]fforts to access the information in our

electronic devices invade and expose the marrow of our

41
Jones, 132 S. Ct. at 954-57 (Sotomayor, J., concurring).
42
State v. Carroll, 2010 WI 8, ¶27, 322 Wis. 2d 299, 778
N.W.2d 1. See Riley, 134 S. Ct. 2473 (requiring warrant for
officers to search the cell phone of an arrestee).
43
State v. Sobczak, 2013 WI 52, 347 Wis. 2d 724, 833
N.W.2d 59, cert. denied sub nom. Sobczak v. Wisconsin, 134 S.
Ct. 626 (2013).
44
Sobczak, 347 Wis. 2d 724, ¶30.
45
Subdiaz-Osorio, 2014 WI 87, ¶40 (Prosser, J., lead op.).
46
Id., ¶41 (Prosser, J., lead op.).
47
Id., ¶40 (Prosser, J., lead op.).
18
 No. 2012AP336-CR.ssa

individuality."48 I, like Justice Prosser, am "mindful of the

pervasiveness of wireless technology and of our citizens'

concern for their privacy . . . ."49

¶86 As the United States Supreme Court recently noted in

Riley, 134 S. Ct. at 2494-95, cell phones involve a privacy

interest far beyond what the Founders envisioned:

Modern cell phones are not just another technological
convenience. With all they contain and all they may
reveal, they hold for many Americans "the privacies of
life," [Boyd v. United States, 116 U. S. 616, 625
(1886).] The fact that technology now allows an
individual to carry such information in his hand does
not make the information any less worthy of the
protection for which the Founders fought.
¶87 In light of these twenty-first-century privacy

concerns and our existing case law holding that law

enforcement's access to an individual's electronic data for

information about the individual's location constitutes a search

within the meaning of the Constitutions, why do the majority

opinion in Tate and Justice Prosser's lead opinion in Subdiaz-

Osorio hedge their bets? Indeed, Justice Roggensack's

concurrence in Subdiaz-Osorio chides Justice Prosser's lead

opinion in Subdiaz-Osorio for daring to even insinuate that a

privacy interest might exist in cell phone location data.50

¶88 The majority opinion in Tate and Justice Prosser's

lead opinion in Subdiaz-Osorio assert that they choose not to

48
Id., ¶42 (Prosser, J., lead op.).
49
Id., ¶45 (Prosser, J., lead op.).
50
Subdiaz-Osorio, 2014 WI 87, ¶¶131-132, 139-137
(Roggensack, J., concurring).

19
 No. 2012AP336-CR.ssa

decide whether the accessing of cell phone location data

constituted searches within the meaning of the Constitutions

because of "caution" as urged by the United States Supreme Court

in City of Ontario, Cal. v. Quon, 560 U.S. 746, 759 (2010).
Tate, majority op., ¶26; Subdiaz-Osorio, 2014 WI 87, ¶64

(Prosser, J., lead op.). Justice Prosser's lead opinion in

Subdiaz-Osorio recites language from Quon stating that "[a]

broad holding concerning employees' privacy expectations vis–à-

vis employer-provided technological equipment might have

implications for future cases that cannot be predicted."

Subdiaz-Osorio, 2014 WI 87, ¶64 (Prosser, J., lead op.) (quoting

Quon, 560 U.S. at 760).

¶89 Contrary to the hand-wringing of the majority opinion

in Tate and Justice Prosser's lead opinion in Subdiaz-Osorio,

recognizing a privacy interest in cell phone location data in

the present cases does not establish far-reaching premises that

define the existence and extent of privacy expectations for all

technology. The court would establish only that government
access to cell phone location data by the means used in these

cases constitutes a search within the meaning of the

Constitutions.

¶90 Technology does change rapidly, but the caution urged

by Quon should hedge in favor of our protecting privacy in the

fact situations presented to us. Caution should steer us to

follow existing Wisconsin case law already recognizing that

government tracking of an individual's cell phone location data

constitutes a search.

20
 No. 2012AP336-CR.ssa

¶91 Regardless of whether one applies the trespass

doctrine or the reasonable expectation of privacy doctrine of

Fourth Amendment jurisprudence, law enforcement access to the

defendants' cell phone location data in both Tate and Subdiaz-
Osorio constitutes a search within the meaning of the

Constitutions.

¶92 I nonetheless analyze both cases through the Fourth

Amendment lenses of both the trespass doctrine and the

reasonable expectation of privacy doctrine.

II

¶93 Under the trespass doctrine, when the government

intrudes upon private property, even if the intrusion is small,

it has performed a search within the meaning of the

Constitutions.51

¶94 The Jones majority opinion held that when law

enforcement "physically occupied private property for the

purpose of obtaining information," a trespassory search occurred

for Fourth Amendment purposes. Jones, 132 S. Ct. at 949-51.
¶95 As Justice Alito notes in his concurrence in Jones,

"some [courts] have held that even the transmission of electrons

that occurs when a communication is sent from one computer to

another is enough" to constitute a trespass.52

51
See Silverman v. United States, 365 U.S. 505, 512 (1961)
("mildest and least repulsive" trespass is still a search).
52
Jones, 132 S. Ct. at 962 (Alito, J., concurring) (citing
CompuServe, Inc. v. Cyber Promotions, Inc., 962 F. Supp. 1015,
1021 (S.D. Ohio 1997); Thrifty–Tel, Inc. v. Bezenek, 46 Cal.
App. 4th 1559, 1566 n.6 (1996)).

21
 No. 2012AP336-CR.ssa

¶96 The defendant's cell phone is private personal

property, a constitutionally protected personal "effect".53 A

physical intrusion into that property with intent to find

information creates a trespassory search.54

¶97 In both Tate and Subdiaz-Osorio, the police received

the defendant's cell phone location data from the cell phone

service provider, but nowhere in either case is it disclosed

exactly how the cell phone location data was accessed.55

See also Jones, 132 S. Ct. at 953 ("Situations involving
merely the transmission of electronic signals without trespass
would remain subject to Katz analysis."). The lead opinion in
Subdiaz-Osorio quotes this language for the proposition that
applying trespass doctrine to electronic data would be
"unnatural," see Subdiaz-Osorio, 2014 WI 87, ¶48 & n.24
(Prosser, J., lead op.), but Jones does not foreclose that
transmission of electronic signals may at times constitute a
trespass.
53
See Carroll, 322 Wis. 2d 299, ¶¶27-28 (treating a cell
phone as a closed container).
54
Courts have treated government intrusions into stored
data on computers as trespasses to a chattel ("an effect" under
the Fourth Amendment). See Sotelo v. DirectRevenue, LLC, 384 F.
Supp. 2d 1219, 1230-32 (N.D. Ill. 2005) (asserting that
intrusion into a computer causing damage to the computer was
sufficient to state a claim for trespass to chattels); see also
Theofel v. Farey-Jones, 359 F.3d 1066, 1072-73 (9th Cir. 2004)
(analogizing violation of the federal Stored Communications Act
with the common law of trespass); International Ass'n of
Machinists and Aeropsace Workers v. Werner-Masuda, 390 F. Supp.
2d 479, 495 (D. Md. 2005) (noting that federal courts treat
computer hackers as "electronic trespassers").
55
"It is not clear from the record exactly how law
enforcement used cell site information . . . ." Tate, majority
op., ¶8.

22
 No. 2012AP336-CR.ssa

¶98 In both Tate and Subdiaz-Osorio, the government
apparently electronically intruded into the defendant's cell

phone by use of either a "ping" from the cell phone company56 or

a "stingray" device,57 both of which implicate a trespassory

search.

¶99 If the cell phone location data was accessed when the

cell phone service provider "pinged" the phone, i.e., actively

sent a signal to trigger the phone to reveal its location, the

entry of an electronic signal into the phone implicated a

trespass.

¶100 If the cell phone location data was accessed through

law enforcement use of a "stingray" device as in Tate, such use

also implicated a trespass.58

The circuit court order issued in Tate required that the
service provider, U.S. Cellular, "shall initiate a signal to
determine the location of the subject's mobile device on the
service provider's network or with such other reference points
as may be reasonable . . . ."
56
Tate, majority op., ¶¶1, 7; Subdiaz-Osorio, 2014 WI 87
¶45 n.19 (Prosser, J., lead op.).
57
Tate, majority op., ¶¶1, 7, 9.
58
A stingray works by mimicking a cellphone tower,
getting a phone to connect to it and measuring signals
from the phone. It lets the stingray operator 'ping,'
or send a signal to, a phone and locate it as long as
it is powered on, according to documents reviewed by
the Journal. The device has various uses, including
helping police locate suspects and aiding search-and-
rescue teams in finding people lost in remote areas or
buried in rubble after an accident.

Jennifer Valentino-Devries, "Stingray" Phone Tracker Fuels
Constitutional Clash, Wall St. J., Sept. 22, 2011, available at
http://online.wsj.com/news/articles/SB10001424053111904194604576
583112723197574 (last visited July 14, 2014).
23
 No. 2012AP336-CR.ssa

¶101 The exact methodology of the "stingray" is of some

secrecy, but a general understanding of its functioning exists.

Apparently the stingray device mimics a cell tower and sends a

signal into the cell phone to trigger a response. The

manufacturers of stingray devices will not discuss how the

technology works. The Wisconsin Department of Justice uses

stingray technology but refuses to disclose the functioning or

use of the stingray device.59
¶102 Even though the State has failed to disclose how the

cell phone location data was obtained in the two cases, it

appears that the government access to cell phone location data

in both cases implicated trespassory intrusions. Nevertheless,

59
See Eric Litke, State Cops Can Track Residents'
Cellphones, Oshkosh Northwestern, Mar. 28, 2014, available at
http://www.thenorthwestern.com/article/20140331/OSH0198/30329010
7/State-cops-can-track-residents-cellphones (last visited July
14, 2014).

Increasingly, local and state law enforcement officers are
tapping into cell phone data using a variety of tools including
stingray devices. Use of these secretive tools has raised
privacy concerns in many jurisdictions. See John Kelly,
Cellphone Data Spying: It's Not Just the NSA, USA Today, June
10, 2014, available at
http://www.usatoday.com/story/news/nation/2013/12/08/cellphone-
data-spying-nsa-police/3902809/ (last visited July 14, 2014).

Additionally, the Obama administration has encouraged state
and local law enforcement to withhold or heavily censor
documents regarding the use of cell phone surveillance tools,
increasingly intervening in routine state public records cases
and criminal trials regarding use of the technology. See Jack
Gillum & Eileen Sullivan, US Pushing Local Cops To Stay Mum on
Surveillance, U.S. News & World Report, June 12, 2014, available
at http://www.usnews.com/news/politics/articles/2014/06/12/us-
pushing-local-cops-to-stay-mum-on-surveillance (last visited
July 14, 2014).

24
 No. 2012AP336-CR.ssa

the majority opinion in Tate and Justice Prosser's lead opinion
in Subdiaz-Osorio do not consider trespass relevant to their

inquiries.

¶103 The majority opinion in Tate simply ignores the

possibility that the intrusion in the instant case constituted a

trespassory search. The Tate majority opinion, ¶¶18-19,

analyzes the case as one in which "physical trespass on a

defendant's property does not apply" or one involving "the

absence of a trespass."

¶104 Justice Prosser's lead opinion in Subdiaz-Osorio

asserts, without citation to any authority or analysis of the

electronic intrusion, that the intrusion did not constitute a

trespass.60 Justice Prosser's lead opinion in Subdiaz-Osorio

concludes that holding electronic manipulation to be a trespass

"would be unnatural."61

¶105 Justice Prosser's lead opinion in Subdiaz-Osorio does

not explicate what makes electronic manipulation "unnatural" and

cites no cases or authority for its proposition, simply stating,
ipse dixit, that "the present case falls under the category of a

non-trespassory search . . . ."62 The basis for the lead

opinion's reasoning remains a mystery.

¶106 The court imprudently assumes that no trespass existed

in the two cases. The determination of trespass should be based

on the State's disclosure of how it obtained the information.

60
Subdiaz-Osorio, 2014 WI 87, ¶50 (Prosser, J., lead op.).
61
Id., ¶48 (Prosser, J., lead op.).
62
Id., ¶49 (Prosser, J., lead op.).

25
 No. 2012AP336-CR.ssa

Any electronic signal entering the individual's phone and

modifying it or triggering a response in any way, however

slight, implicates a trespassory search.

III

¶107 Justice Prosser's lead opinion in Subdiaz-Osorio
correctly recites the two-part test set out in Katz v. United

States, 389 U.S. 347 (1967), of the "reasonable expectation of

privacy" standard for what constitutes a search within the

meaning of the Constitution.63

¶108 Katz states that a search occurs when a person has

both: a) a subjective expectation of privacy; and b) an

expectation of privacy "that society is prepared to recognize as

'reasonable.'" Katz, 389 U.S. 347, 361 (Harlan, J.,

concurring).64

¶109 Justice Prosser's lead opinion in Subdiaz-Osorio

explains why the individual defendant in that case had a

subjective expectation of privacy in cell phone location data,

Subdiaz-Osorio, 2014 WI 87, ¶53-64 (Prosser, J., lead op.), and
why society recognizes an expectation of privacy in cell phone

location data, Subdiaz-Osorio, 2014 WI 87, ¶¶42, 45, 65-68

(Prosser, J., lead op.). Yet, in the end, Justice Prosser's

lead opinion in Subdiaz-Osorio refuses to recognize an

individual's right to privacy in cell phone location data.

63
Id., ¶¶51-52 (Prosser, J., lead op.).
64
The United States Supreme Court has acknowledged that the
Katz test "has often been criticized as circular, and hence
subjective and unpredictable." Kyllo v. United States, 533 U.S.
27, 34 (2001).

26
 No. 2012AP336-CR.ssa

¶110 I would hold that the government access to cell phone

location data in both cases violated both the subjective and

objective reasonable expectations of privacy.

A

¶111 In order to determine whether government access to

cell phone location data constitutes a search within the meaning

of the Constitutions, a court addresses the first prong of the

Katz test, namely that the person must have a subjective
expectation of privacy in the area being searched.

¶112 Although individuals may be generally aware that their

locations may be tracked through their cell phones, most do not

realize the extent of tracking possible65 and reasonably do not
65
If you have a cell phone in your pocket, then the
government can watch you. At the government's
request, the phone company will send out a signal to
any cell phone connected to its network, and give the
police its location. [In 2009] law enforcement agents
pinged users of just one service provider——Sprint——
over eight million times. The volume of requests grew
so large that the 110-member electronic surveillance
team couldn't keep up, so Sprint automated the process
by developing a web interface that gives agents direct
access to users' location data. Other cell phone
service providers are not as forthcoming about this
practice, so we can only guess how many millions of
their customers get pinged by the police every year.

United States v. Pineda-Moreno, 617 F.3d 1120, 1125 (9th Cir.
2010) (Kozinski, J., dissenting) (citations omitted).

The Tate warrant approves collecting open-ended and
undefined data from the cell phone service provider, such as:
"any historical information law enforcement may request to
include historical cell site information from 6/9/2009 through
this order's duration . . . ." The order's duration extends
over a long period of time——60 days——and requires that the cell
phone service provider "shall provide all technical assistance
necessary to accomplish this order and disclose the records and
other information described herein twenty-four hours a day."
27
 No. 2012AP336-CR.ssa

expect the cell phone service provider to report their precise

location to law enforcement officers. It does not comport with

the reality of the modern telecommunications age that

individuals lose their constitutional right to privacy in their

location simply by purchasing a cell phone.

¶113 In accord with the comments in Justice Prosser's lead

opinion in Subdiaz-Osorio,66 I would hold that the defendants had
a subjective reasonable expectation of privacy in the cell phone

location data.

¶114 I turn to the questions of whether the cell phone

service provider's contract or an individual's disclosure of his

cell phone location data to the cell phone service provider (a

third party) undermined the individual's subjective expectation

of privacy in cell phone location data.

1

¶115 The cell phone service provider contract is referenced

in Justice Prosser's lead opinion in Subdiaz-Osorio. The State

argues that the contract removes the defendant's subjective
expectation of privacy in his cell phone location data.

¶116 I conclude that the contract in question in Subdiaz-

Osario was a contract of adhesion, a "take-it-or-leave-it"

This surveillance goes far beyond the traditional scope of
a search warrant, aided by technology that has now rendered
broad searches practicable.
66
Subdiaz-Osorio, 2014 WI 87, ¶¶53-61 (Prosser, J., lead
op.).

28
 No. 2012AP336-CR.ssa

contract that the individual could not and did not negotiate.67
Consequently, I would at a minimum construe ambiguous or vague

terms against the drafter.68

¶117 Justice Prosser's lead opinion in Subdiaz-Osorio

points out a variety of potentially unclear language in the

defendant's cell phone service provider contract. Subdiaz-

Osorio, ¶¶56-58 (Prosser, J., lead op.).

¶118 Justice Prosser's lead opinion in Subdiaz-Osorio also

avers that such a complex and potentially confusing contract

should not constitute the basis for consent to a search.

Subdiaz-Osorio, 2014 WI 87, ¶59 (Prosser, J., lead op.). Why

not? Law enforcement officers are already expected to navigate

a thicket of case law and facts when performing a consent

search. The "totality of the circumstances" analysis when

determining whether consent to a search has been properly given

often involves careful weighing of a variety of legal

67
See Wis. Auto Title Loans v. Jones, 2006 WI 53, ¶52, 290
Wis. 2d 514, 714 N.W.2d 155 (quoting Acorn v. Household Int'l,
Inc., 211 F. Supp. 2d 1160, 1168 (N.D. Cal. 2002)).
68
"The principle that ambiguities are construed against the
drafter is a deeply rooted doctrine of contract interpretation."
Maryland Arms Ltd. P'ship v. Connell, 2010 WI 64, ¶44, 326
Wis. 2d 300, 786 N.W.2d 15 (internal quotation marks omitted).

29
 No. 2012AP336-CR.ssa

relationships between family members, romantic partners,

roommates, landlords and tenants, etc.69
¶119 I also look, as I have stated previously, to the

reality of cell phone usage by the everyday purchaser of a cell

phone: When accepting an adhesion contract to purchase cell

phone service——an increasingly necessary component of everyday

life——the purchaser is not bargaining for unfettered government

access to the purchaser's cell phone location data.

¶120 The breadth of the data covered by the contract and

the lack of clarity regarding the circumstances enabling the

cell phone service provider to transmit the data to the

government mandate that the court hold that the purchaser did

not consent to government access to his or her cell phone

location data.

¶121 Thus, I conclude that the defendant in Subdiaz-Osorio

did not relinquish his subjective expectation of privacy or

69
See, e.g., State v. Kieffer, 217 Wis. 2d 531, 577
N.W.2d 352 (1998) (requiring police to ask additional clarifying
questions when third-party landowner's apparent authority to
search the tenant-defendant's apartment was unclear); State v.
Tomlinson, 2002 WI 91, 254 Wis. 2d 502, 648 N.W.2d 367
(determining that police could reasonably assume that 14-year-
old girl at the door of a residence had apparent authority to
consent to its search even though they had no evidence that the
girl was the resident's daughter); Sobczak, 347 Wis. 2d 724
(deeming it reasonable for police to assume that a defendant's
girlfriend had actual authority to consent to a search of the
defendant's laptop, even though the girlfriend was a houseguest
and not a cotenant); State v. St. Germaine, 2007 WI App 214, 305
Wis. 2d 511, 740 N.W.2d 148 (holding that when a tenant-
defendant did not object to the landlord's consent to search the
entire residence, and when the police did not know that a
particular room belonged to the tenant-defendant, the landlord
had apparent authority to consent to the search).

30
 No. 2012AP336-CR.ssa

consent to a search based on the cell phone service provider

contract.

2

¶122 I turn now to the "third-party doctrine," which is

often broadly stated as follows: When an individual voluntarily

provides information to a third party, the individual does not

have a reasonable subjective expectation of privacy in the

information.70
¶123 In the instant cases, the defendants' cell phones

conveyed location information to the cell phone service

provider, a third party, as a necessary component of the

functioning of the phone. The defendants apparently cannot opt

out of giving this information to the service provider.

¶124 Thus the very use of the cell phone, as well as the

contract with the cell phone service provider, implicates the

third-party doctrine.

¶125 Justice Roggensack's concurrence in Subdiaz-Osorio

opines that the defendants in Tate and Subdiaz-Osorio had no

70
See United States v. Miller, 425 U.S. 435 (1976) (holding
a bank depositor had no reasonable expectation of privacy in his
or her bank records); Smith v. Maryland, 442 U.S. 735 (1979)
(holding that use of a pen register, a device that records the
phone numbers dialed by an individual, does not constitute a
search under the reasonable expectation of privacy analysis).

Congress and many state legislatures, including the
Wisconsin legislature, subsequently created a procedure for
issuing pen registers that protects an individual's privacy
interests. See 18 U.S.C. § 3123 (2006); Wis. Stat. §§ 968.34-
.36. See also Right to Financial Privacy Act of 1978, 12 U.S.C
§§ 3401-3421 (1980) (protections to prevent government access
into private bank records without meeting specific
requirements).

31
 No. 2012AP336-CR.ssa

reasonable expectation of privacy because "a defendant typically

retains no constitutional reasonable expectation of privacy in

information conveyed to a third party." Subdiaz-Osorio, 2014 WI
87, ¶135 (Roggensack, J., concurring) (internal quotation marks

& citation omitted); see also Tate, majority op., ¶25.

¶126 In the modern world, in which we regularly disclose

information to third parties as part of everyday life, the

third-party doctrine is ailing as a principle of law.

¶127 The third-party doctrine has been limited in scope

since it was stated broadly in United States v. Miller, 425 U.S.

435, 443 (1976), a case that predates cellular phones. In

Miller, the Court held that a bank depositor had no reasonable

expectation of privacy in his or her bank records.

¶128 Smith v. Maryland, 442 U.S. 735 (1979), applied the

reasoning of Miller, rejecting the argument that telephone

subscribers harbor any general expectation that the numbers they

dial, which are conveyed to the telephone company, will remain

secret.
¶129 Miller and Smith represented the high-water mark for

the third-party doctrine, which has receded ever since.

Although the third-party doctrine has been defended vigorously

by at least one prominent scholar, Orin Kerr, on the grounds

that it provides clarity and ensures technological neutrality,71

the Miller opinion was met with criticism as both overly broad

and unsatisfactory in its failure to balance privacy rights of

71
See Orin Kerr, The Case for the Third-Party Doctrine, 107
Mich. L. Rev. 561 (2009).

32
 No. 2012AP336-CR.ssa

individuals against the law enforcement interest in

investigating crimes.72

72
See Note, Government Access to Bank Records, 83 Yale L.J.
1439, 1464-65 (1974) (criticizing the doctrine as outdated, and
asserting that denial of a privacy interest in third-party
records "leads to the anomalous conclusion that, while
safeguarded against all others, the depositor's privacy would be
nonexistent when the prying eye belongs to the government");
Albert W. Alschuler, Interpersonal Privacy and the Fourth
Amendment, 4 N. Ill. U. L. Rev. 1, 22 (1983) (noting that
reactions to Miller were "overwhelmingly negative" and decrying
the alarming breadth of the third-party doctrine announced
therein); Matthew Tokson, Automation and the Fourth Amendment;
96 Iowa L. Rev. 581, 585-86 (2011) (criticizing the third-party
doctrine as "problematic in an age where an ever-growing
proportion of personal communications and transactions are
carried out over the Internet," all accessible to third-party
Internet service providers, among others).

Professor LaFave has joined others in criticizing the
third-party doctrine. 1 Wayne R. LaFave, Search & Seizure
§ 2.7(c) (5th ed. 2012) (footnotes omitted):

The result reached in Miller is dead wrong, and the
Court's woefully inadequate reasoning does great
violence to the theory of Fourth Amendment protection
the Court had developed in Katz.

. . . .

The Court's assertion in Miller that there can be no
protected Fourth Amendment interest where there is
"neither ownership nor possession" is contrary to the
purposes underlying the Fourth Amendment, the
teachings of Katz, and the realities of modern-day
life. Ownership and possession are property concepts
which, the Court wisely concluded in Katz, "cannot
serve as a talismanic solution to every Fourth
Amendment problem," and which surely do not lead to
the proper solution in this context. Unquestionably,
the "Fourth Amendment's drafters were . . . concerned
with privacy in the sense of control over
information."

33
 No. 2012AP336-CR.ssa

¶130 Since Miller and Smith, courts have used the third-
party doctrine with decreasing frequency and have limited third-

party cases to the facts at hand, leading some commentators to

deem the doctrine either dead or of limited viability.73

¶131 Either ignoring or contravening the third-party

doctrine, courts now recognize a reasonable expectation of

privacy in certain types of information regardless of their

disclosure to third parties, such as health records,74 heat

emanating from a house,75 files entrusted to an attorney by a

client,76 tax records entrusted to a tax preparer,77 or e-mail

records.78

73
See, e.g., Stephen E. Henderson, After United States v.
Jones, After the Fourth Amendment Third Party Doctrine, 14 N.C.
J.L. & Tech. 431 (2013) (reasoning that courts have been
hesitant to apply the third-party doctrine in recent years, and
attacking the doctrine as incongruent with modern culture).
74
In Ferguson v. City of Charleston, 532 U.S. 67 (2001),
the Court recognized that pregnant women had a privacy interest
in collected urine samples and invalidated a program that shared
samples given at a hospital with law enforcement. The dissent,
authored by Justice Scalia, noted that the Court did not address
the third-party doctrine.
75
Kyllo, 537 U.S. 27.
76
DeMassa v. Nunez, 770 F.2d 1505 (9th Cir. 1985).
77
People v. Gutierrez, 222 P.3d 925 (Colo. 2009).
78
United States v. Warshak, 631 F.3d 266 (6th Cir. 2010)
(asserting that an individual enjoys a reasonable expectation of
privacy in e-mails vis-à-vis his or her internet service
provider and that government agents violated the individual's
Fourth Amendment rights by compelling disclosure of his emails
from the internet service provider without a warrant).

34
 No. 2012AP336-CR.ssa

¶132 Justice Sotomayor got it right in her concurrence in

Jones, 132 S. Ct. at 957, which casts doubt on the continued
viability of a broad third-party doctrine in the digital age:

This approach is ill suited to the digital age, in
which people reveal a great deal of information about
themselves to third parties in the course of carrying
out mundane tasks. People disclose the phone numbers
that they dial or text to their cellular providers;
the URLs that they visit and the e-mail addresses with
which they correspond to their Internet service
providers; and the books, groceries, and medications
they purchase to online retailers. . . . . I for one
doubt that people would accept without complaint the
warrantless disclosure to the Government of a list of
every Web site they had visited in the last week, or
month, or year. But whatever the societal
expectations, they can attain constitutionally
protected status only if our Fourth Amendment
jurisprudence ceases to treat secrecy as a
prerequisite for privacy. I would not assume that all
information voluntarily disclosed to some member of
the public for a limited purpose is, for that reason
alone, disentitled to Fourth Amendment protection.79
¶133 Although Justice Roggensack's concurrence in Subdiaz-

Osorio reproaches Justice Prosser's lead opinion in Subdiaz-

Osorio for "question[ing] the continued viability of the third

party disclosure doctrine itself,"80 the viability of the third-

party disclosure doctrine is already questioned by existing case

law and by Justice Sotomayor's concurrence in Jones, which the

Tate majority opinion cites favorably.81 Indeed, the Eleventh
79
The third-party doctrine also arose in Riley, 134 S. Ct.
at 2492-93. The Court did not adopt the government's argument
to uphold the search based on the third-party doctrine as stated
in Smith, 442 U.S. 735.
80
Subdiaz-Osorio, 2014 WI 87, ¶135 (Roggensack, J.,
concurring).
81
Tate, majority op., ¶25.

35
 No. 2012AP336-CR.ssa

Circuit Court of Appeals has rejected the use of the third-party

doctrine in evaluating whether government access to cell phone

location data was a search, reasoning that because the defendant

probably had no idea that he was allowing the cell phone

provider to follow his movements, he "has not voluntarily

disclosed his cell site location information to the provider in

such a fashion as to lose his reasonable expectation of

privacy." Davis, 2014 WL 2599917 at *10.
¶134 The ABA standards for law enforcement access to third-

party records, cited favorably by Justice Roggensack's

concurrence in Subdiaz-Osorio,82 advocate a finer-grained

approach to data disclosed to third parties, rejecting a broad

third-party doctrine in favor of differing protections for

differing levels of expected privacy in data.83

¶135 I conclude that neither defendant lost his expectation

of privacy in his cell phone location data simply because the

location data was disclosed to the cell phone service provider.

People do not buy cell phones to have them serve as government
tracking devices.

B

¶136 For several reasons I conclude that society recognizes

a reasonable expectation of privacy in an individual's cell

phone location data.

82
Subdiaz-Osorio, 2014 WI 87, ¶135 (Roggensack, J.,
concurring).
83
ABA Standards for Criminal Justice, Law Enforcement
Access to Third Party Records Standard 25-4.1 & cmt., at 63 (3d
ed. 2013).

36
 No. 2012AP336-CR.ssa

¶137 First, the Wisconsin GPS case law (Brereton)84 has

recognized an individual's subjective expectation of privacy in

the individual's location and has declared that government

access to GPS location data is a search within the meaning of

the Constitutions.85 Justice Sotomayor's concurrence in Jones

similarly recognizes that even short-term GPS monitoring can

reveal a wealth of information about a person's private behavior

that he or she chooses not to expose to the world at large and

that society should protect this choice.86

¶138 Second, in addition to the case law determining that

government access to an individual's GPS location data is a

violation of an individual's objective reasonable expectation of

privacy, state and federal laws have long protected individual

communications and records disclosed to third parties from

government access.

¶139 Our statutes recognize that individuals have a privacy

interest in electronic and communications data, including oral,

electronic, and wire communications;87 dialed phone numbers;88 and

84
Brereton, 345 Wis. 2d 563.
85
See ¶¶79-81, supra (discussing Brereton).
86
Jones, 132 S. Ct. 945, 955-56 (2012) (Sotomayor, J.,
concurring).
87
See Wis. Stat. § 968.31 (prohibiting the interception of
wire, electronic, or oral communication, except as provided and
authorized by judicial order)
88
See Wis. Stat. § 968.34 (prohibiting any person,
including law enforcement, from installing a pen register or
trap-and-trace device absent a court order).

37
 No. 2012AP336-CR.ssa

other records stored by communications services, such as name,

address, session times and durations, billing information, etc.89
¶140 Third, society recognizes an individual's subjective

reasonable expectation of privacy in location data regardless of

whether the tracking is in public or private spaces.

¶141 The majority opinion in Tate suggests that tracking of

cell phone location in Tate required a warrant "because the

tracking led law enforcement to discover Tate's location within

his mother's home."90 The Tate majority opinion cites United

States v. Knotts, 460 U.S. 276, 281 (1983), and State v. Sveum,

2010 WI 92, ¶79, 328 Wis. 2d 369, 787 N.W.2d 317 (Ziegler, J.,

concurring) for the proposition that tracking in public places

does not constitute a search. Tate, majority op., ¶23.

¶142 Yet the facts of Tate and Subdiaz-Osorio demonstrate

that the public/private space distinction has become blurry. In

Tate, when law enforcement officers initiated the tracking, they

did not know whether the cell phone would be in public or

private areas. Stingray devices owned by law enforcement gather
location information about a cell phone whether it is in a

public or private space. Similarly, the law enforcement

officers did not know in Subdiaz-Osorio whether the defendant

would be on a public highway or in a private residence (or

similarly protected space, e.g., a hotel room).

89
See Wis. Stat. § 968.375 (creating statutory subpoenas
for disclosure of certain information by electronic
communications services and prohibiting disclosure unless the
disclosure fits into certain exceptional categories).
90
Tate, majority op., ¶2; see also id., ¶¶23, 51.

38
 No. 2012AP336-CR.ssa

¶143 True, in older jurisprudence, the United States

Supreme Court distinguished between police surveillance of

location in which the tracking device entered a home and

surveillance in which the tracking device monitored movements

only in public spaces. Compare Knotts, 460 U.S. at 281–83 (no
Fourth Amendment violation when beeper surveillance on a vehicle

tracked the vehicle on public streets and highways) with United

States v. Karo, 468 U.S. 705, 714 (1984) (warrant was required

to use a beeper to monitor the location of a container that was

inside a vehicle on public roads, and then moved inside a

private space).

¶144 This distinction between tracking in public and

private spaces is eroded in the case of cell phone location

data, which can be used to track movements across both public

and private spaces.

¶145 This difficulty does not erode core privacy

protections of residences. In Tate, upon determining the

location of the phone, law enforcement officers entered the home
of the defendant's mother. Entry into the home was a search

separate and distinct from law enforcement's access to the cell

phone location data. The warrantless entry into the home was

not covered by the warrant in Tate, which authorized the

officers to search only for the location data. Rather, the

warrantless entry into the home was based on consent, an

exception to the warrant requirement.91 Simply because new

91
The defendant in Tate disputed the issue of consent at
the circuit court, but did not raise the issue in this court.

39
 No. 2012AP336-CR.ssa

technology reveals new areas of privacy does not mean that

existing privacy interests are lost.92
¶146 Fourth, the Wisconsin legislature has recognized the

public's reasonable expectation of privacy in cell phone

location data. The Wisconsin legislature has recently enacted

2013 Wis. Act 375, creating Wis. Stat. § 968.373 (2013-14), with

support across ideological and partisan lines.93

¶147 Newly enacted Wis. Stat. § 968.373, reprinted as an

appendix, contains protections for location data from wireless

or mobile devices. Subsection 968.373(2) explicitly prohibits

law enforcement from identifying or tracking the location of a

communications device without first obtaining a warrant as

defined by the statute:

PROHIBITION. Except as provided in sub. (8) [the
statutory emergency exception], no investigative or
law enforcement officer may identify or track the
location of a communications device without first
obtaining a warrant under sub. (4).
By creating this statute, the Wisconsin legislature has

reflected society's willingness to recognize the individual's
subjective expectation of privacy.

¶148 Although the new legislation post-dates the searches

in Tate and Subdiaz-Osorio, this court has examined legislation

92
See Kyllo, 533 U.S. at 37-40 (noting that although heat-
imaging technology was novel, core protections of privacy in
homes remained intact).
93
Of the bill's 22 Assembly sponsors, 14 were Republicans
and 8 were Democrats. The bill's two co-sponsors in the Senate
were John Lehman (D-Racine) and Glenn Grothman (R-West Bend).
It was also unanimously approved by the Wisconsin Assembly
Committee on Judiciary.

40
 No. 2012AP336-CR.ssa

not applicable to the case before it to help us understand the

state's public policy. See Kimble v. Land Concepts, Inc., 2014
WI 21, ¶65 n.24, 353 Wis. 2d 377, 845 N.W.2d 395 ("While the

statute is not applicable to this case, it is nonetheless

appropriate to consider the legislature's judgment of a

reasonable disparity of punitive to compensatory damages.");

McGarrity v. Welch Plumbing Co., 104 Wis. 2d 414, 427, 312

N.W.2d 37 (1981) (interpreting purpose of child labor laws based

on later enactments on the same topic).

¶149 For all these reasons, I conclude that society is

willing to recognize as reasonable and protect individuals'

subjective reasonable expectation of privacy in cell phone

location data.

IV

¶150 Because I conclude that in both Tate and Subdiaz-

Osorio the government's access to the defendant's cell phone

location data was a search within the meaning of the

Constitutions, the warrant requirement applies. Thus, law
enforcement needed a valid warrant to access the defendants'

cell phone location data. In Tate, no warrant was obtained in

compliance with the state statutes. No warrant was obtained at

all in Subdiaz-Osorio.94

94
Justice Prosser's lead opinion in Subdiaz-Osorio does,
however, comment on warrant requirements, although its precise
meaning for courts and law enforcement is unclear:

A court order that meets the requirements of the
Fourth Amendment may function as a warrant. State v.
Tate, 2014 WI 89, ¶2 & n.4, ___ Wis. 2d ___, ___
N.W.2d ___; see also State v. Sveum, 2010 WI 92, ¶39,
328 Wis. 2d 369, 787 N.W.2d 317. However, when a
41
 No. 2012AP336-CR.ssa

¶151 Our state legislature has promulgated statutes

governing search warrants since 1849.95
¶152 Existing statutes governing warrants apply directly to

a search for cell phone location data held by a cell phone

provider, as the Tate majority opinion concedes.96 The Tate

majority opinion states that existing warrant statutes, Wis.

Stat. §§ 968.1297 and 968.135,98 are clear and directly on point,

statute provides procedures for obtaining a warrant in
a given set of circumstances, law enforcement should
follow the statute to ensure that a search conducted
under the circumstances contemplated by the statute
does not violate a person's Fourth Amendment rights.

Subdiaz-Osorio, 2014 WI 87, ¶5 n.2 (Prosser, J., lead op.).
95
See Wis. Stat. ch. 142, §§ 1-4 (1849).
96
Tate, majority op., ¶¶45-50.
97
Wisconsin Stat. § 968.12 states as follows:

Search warrant

(1) Description and issuance. A search warrant is an
order signed by a judge directing a law enforcement
officer to conduct a search of a designated person, a
designated object or a designated place for the
purpose of seizing designated property or kinds of
property. A judge shall issue a search warrant if
probable cause is shown.

(2) Warrant upon affidavit. A search warrant may be
based upon sworn complaint or affidavit, or testimony
recorded by a phonographic reporter or under sub.
(3)(d), showing probable cause therefor. The
complaint, affidavit or testimony may be upon
information and belief.

(3) Warrant upon oral testimony. (a) General rule. A
search warrant may be based upon sworn oral testimony
communicated to the judge by telephone, radio or other
means of electronic communication, under the procedure
prescribed in this subsection.
42
 No. 2012AP336-CR.ssa

(b) Application. The person who is requesting the
warrant shall prepare a duplicate original warrant and
read the duplicate original warrant, verbatim, to the
judge. The judge shall enter, verbatim, what is read
on the original warrant. The judge may direct that
the warrant be modified.

(c) Issuance. If the judge determines that there is
probable cause for the warrant, the judge shall order
the issuance of a warrant by directing the person
requesting the warrant to sign the judge's name on the
duplicate original warrant. In addition, the person
shall sign his or her own name on the duplicate
original warrant. The judge shall immediately sign
the original warrant and enter on the face of the
original warrant the exact time when the warrant was
ordered to be issued. The finding of probable cause
for a warrant upon oral testimony shall be based on
the same kind of evidence as is sufficient for a
warrant upon affidavit.

(d) Recording and certification of testimony. When a
caller informs the judge that the purpose of the call
is to request a warrant, the judge shall place under
oath each person whose testimony forms a basis of the
application and each person applying for the warrant.
The judge or requesting person shall arrange for all
sworn testimony to be recorded either by a
stenographic reporter or by means of a voice recording
device. The judge shall have the record transcribed.
The transcript, certified as accurate by the judge or
reporter, as appropriate, shall be filed with the
court. If the testimony was recorded by means of a
voice recording device, the judge shall also file the
original recording with the court.

(e) Contents. The contents of a warrant upon oral
testimony shall be the same as the contents of a
warrant upon affidavit.

(f) Entry of time of execution. The person who
executes the warrant shall enter the exact time of
execution on the face of the duplicate original
warrant.

(4) Location of search. A search warrant may
authorize a search to be conducted anywhere in the
43
 No. 2012AP336-CR.ssa

and discusses these statutes and the important protections they

provide. Tate, majority op., ¶¶45-50.
¶153 Indeed, the Tate majority opinion acknowledges that

the circuit court's order for such data "should have" complied

with the statutes governing warrants and governing subpoenas for

documents in criminal cases, Wis. Stat. §§ 968.12 and 968.135,

and that these statutes "express legislative choices about

procedures to employ for warrants and criminal subpoenas."

Tate, majority op., ¶¶49-51.99

state and may be executed pursuant to its terms
anywhere in the state.
98
Wisconsin Stat. § 968.135 states as follows:

Subpoena for documents

Upon the request of the attorney general or a district
attorney and upon a showing of probable cause under s.
968.12, a court shall issue a subpoena requiring the
production of documents, as specified in s. 968.13(2).
The documents shall be returnable to the court which
issued the subpoena. Motions to the court, including,
but not limited to, motions to quash or limit the
subpoena, shall be addressed to the court which issued
the subpoena. Any person who unlawfully refuses to
produce the documents may be compelled to do so as
provided in ch. 785. This section does not limit or
affect any other subpoena authority provided by law.
99
Indeed, we made clear in State v. Popenhagen, 2008 WI 55,
¶84, 309 Wis. 2d 601, 749 N.W.2d 611, that "the objective of
[the criminal subpoena statute, Wis. Stat.] § 968.135[,] is to
allow the State to acquire and use documents while also ensuring
that the State meets statutory requirements that protect the
privacy interests of persons affected by the subpoena."

We further held in Popenhagen that failure to comply with
the requirements of Wis. Stat. § 968.135 results in an invalid
warrant and that such a violation justified suppression of
evidence obtained by the invalid warrant. Popenhagen, 309
Wis. 2d 601, ¶97.

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¶154 Despite its acknowledgement of the existence of

statutes directly applicable to the circumstances in Tate, the
Tate majority opinion asserts that failure to comply with these

statutes does not invalidate the search warrant. Tate, majority

op., ¶42. The majority opinion in Tate turns a blind eye to the

failure of the warrant to comply with multiple requirements of

Wis. Stat. § 968.135, which clearly governs the fact situation

in Tate, instead asserting that "[n]o specific statutory

authority is necessary" in the instant case.

¶155 If the statutes "express legislative choices," why

does the Tate majority opinion rule that these legislative

choices require only compliance with the "spirit" of the statute

rather than compliance with the text of the statute? Tate,

majority op., ¶¶2, 51.

¶156 The Tate majority opinion assures us that, despite

compliance "in spirit" rather than actual compliance with the

text, "[the defendant] was not deprived of Wis. Stat.

§ 968.135's safeguards." Tate, majority op., ¶50.100
¶157 Yet the warrant in Tate failed to comply with almost

all of the statutory requirements of the subpoena statute.

Wisconsin Stat. § 968.135 requires that "[t]he documents shall

be returnable to the court which issued the subpoena." The

order in the instant case does not mention the return of any of

the data recovered to the circuit court.

100
Wisconsin Stat. § 968.135 asserts that it "does not
limit or affect any other subpoena authority provided by law,"
but the majority opinion describes a nonstatutory "warrant," not
subpoena authority.

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¶158 Wisconsin Stat. § 968.135 requires that "[m]otions to

the court, including, but not limited to, motions to quash or

limit the subpoena, shall be addressed to the court which issued

the subpoena." The order in the instant case never provided any

opportunity for motions to the court, because it was immediately

ordered to "be sealed until otherwise ordered by the court."

¶159 Wisconsin Stat. § 968.135 does not authorize the

sealing of subpoenas. The circuit court sealed documents,

relying on the statute that authorizes the sealing of orders for

pen registers or trap-and-trace devices.101 The instant case did

not involve either a pen register or trap-and-trace device.

¶160 These defects should have rendered the warrant invalid

under Wis. Stat. § 968.135.

¶161 To avoid this result, the Tate majority opinion

devises a new rule: A statute directly governing a warrant in

the particular circumstances of a case need not be followed.

¶162 Tate's new rule ignores the longstanding jurisprudence

in this state. When a statute exists governing the warrant at
issue, it must be followed unless the legislature expressed its

intent otherwise. If the statutory requirements are not met,

101
See Wis. Stat. § 968.36(5).

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the warrant is invalid.102 If no statute covers the search in

question, law enforcement may seek a warrant if the warrant

would have been permissible at common law. See Meek v. Pierce,

19 Wis. 318 (*300), 322 (*303) (1865).103 How will the majority

opinion in Tate apply to the new statute directly governing law

enforcement access to cell phone location data?

¶163 For the reasons set forth, I conclude that the law

enforcement officers in Tate had to comply with Wis. Stat.

§ 968.135 to obtain a valid warrant to access the defendant's

cell phone location data. They did not. Consequently, I

conclude that no valid warrant was obtained in Tate.

* * * *

¶164 Unlike the majority opinion in Tate and Justice

Prosser's lead opinion in Subdiaz-Osorio, I conclude that

government access to cell phone location data in the present

cases is a search within the meaning of the Constitutions that

requires a warrant, and that the warrant must comply with the

102
See, e.g., State v. Baltes, 183 Wis. 545, 198 N.W. 282
(1924) (determining that when law enforcement failed to secure
sworn testimony as required by the warrant statute, Wis. Stat.
§§ 4839-40 (1923), the warrant was invalid for failing both the
statutory and constitutional requirements); Glodowski v. State,
196 Wis. 265, 220 N.W. 227 (1928) (determining that when a
search warrant was issued to search a private residence for
liquor without evidence of "unlawful manufacture for sale,
unlawful sale, or possession for sale, of liquor" as required by
the statute, the warrant was void).
103
In Meek, no statute gave magistrates the power to
authorize warrants against private persons in criminal matters
and no statute denied this power to magistrates. Meek, 19 Wis.
at 321 (*302-303). The Meek court held that the prior common-
law rules applied as a matter of statutory interpretation.

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existing directly applicable statutes. The warrant in Tate did
not comply with the existing statutes and is invalid. No

warrant was obtained in Subdiaz-Osorio.

¶165 Because the various writings in Tate and Subdiaz-

Osorio fail to protect privacy, I write in dissent.

¶166 I am authorized to state that Justice ANN WALSH

BRADLEY joins Parts I-IV of this dissent.

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APPENDIX

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2
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3
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1