Case Title: State v. Tate

Citation: 2014 WI 89

Docket Number: 2012AP000336-CR

State: wisconsin

Court: Wisconsin Supreme Court

Date: 2014-07-24T00:00:00Z

Document:
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 App. 2012 – Unpublished)  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, 
 
     v. 
 
Bobby L. Tate, 
 
          Defendant-Appellant-Petitioner. 
FILED 
 
JUL 24, 2014 
 
Diane M. Fremgen 
Clerk of Supreme Court 
 
 
 
 
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unpublished decision of the court of appeals1 affirming the 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1 State v. Tate, No. 2012AP336-CR, unpublished slip op.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   
 
2 
 
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).  
No. 
2012AP336-CR   
 
3 
 
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. 
No. 
2012AP336-CR   
 
4 
 
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 
No. 
2012AP336-CR   
 
5 
 
¶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). 
No. 
2012AP336-CR   
 
6 
 
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 
No. 
2012AP336-CR   
 
7 
 
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).   
No. 
2012AP336-CR   
 
8 
 
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").  
No. 
2012AP336-CR   
 
9 
 
¶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."  
No. 
2012AP336-CR   
 
10 
 
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 
No. 
2012AP336-CR   
 
11 
 
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 
No. 
2012AP336-CR   
 
12 
 
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.  
No. 
2012AP336-CR   
 
13 
 
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.) 
No. 
2012AP336-CR   
 
14 
 
¶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). 
No. 
2012AP336-CR   
 
15 
 
¶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 
No. 
2012AP336-CR   
 
16 
 
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. 
No. 
2012AP336-CR   
 
17 
 
¶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. 
No. 
2012AP336-CR   
 
18 
 
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 
No. 
2012AP336-CR   
 
19 
 
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."). 
No. 
2012AP336-CR   
 
20 
 
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 
No. 
2012AP336-CR   
 
21 
 
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).   
No. 
2012AP336-CR   
 
22 
 
¶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.  
No. 
2012AP336-CR   
 
23 
 
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 
No. 
2012AP336-CR   
 
24 
 
¶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 
No. 
2012AP336-CR   
 
25 
 
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"). 
No. 
2012AP336-CR   
 
26 
 
¶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.  
No. 
2012AP336-CR   
 
27 
 
¶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").  
No. 
2012AP336-CR   
 
28 
 
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 
No. 
2012AP336-CR   
 
29 
 
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.  
 
 
 
No.  2012AP336-CR.ssa 
 
1 
 
¶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 
No.  2012AP336-CR.ssa 
 
2 
 
¶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. 
No.  2012AP336-CR.ssa 
 
3 
 
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)). 
No.  2012AP336-CR.ssa 
 
4 
 
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. 
No.  2012AP336-CR.ssa 
 
5 
 
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. 
No.  2012AP336-CR.ssa 
 
6 
 
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. 
No.  2012AP336-CR.ssa 
 
7 
 
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.)). 
No.  2012AP336-CR.ssa 
 
8 
 
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.   
No.  2012AP336-CR.ssa 
 
9 
 
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. 
No.  2012AP336-CR.ssa 
 
10 
 
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.  
No.  2012AP336-CR.ssa 
 
11 
 
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. 
No.  2012AP336-CR.ssa 
 
12 
 
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. 
No.  2012AP336-CR.ssa 
 
13 
 
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. 
No.  2012AP336-CR.ssa 
 
14 
 
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). 
No.  2012AP336-CR.ssa 
 
15 
 
¶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). 
No.  2012AP336-CR.ssa 
 
16 
 
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). 
No.  2012AP336-CR.ssa 
 
17 
 
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). 
No.  2012AP336-CR.ssa 
 
18 
 
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.). 
No.  2012AP336-CR.ssa 
 
19 
 
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). 
No.  2012AP336-CR.ssa 
 
20 
 
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.   
No.  2012AP336-CR.ssa 
 
21 
 
¶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)). 
No.  2012AP336-CR.ssa 
 
22 
 
¶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. 
No.  2012AP336-CR.ssa 
 
23 
 
¶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). 
No.  2012AP336-CR.ssa 
 
24 
 
¶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). 
No.  2012AP336-CR.ssa 
 
25 
 
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.).     
No.  2012AP336-CR.ssa 
 
26 
 
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).  
No.  2012AP336-CR.ssa 
 
27 
 
 
¶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." 
No.  2012AP336-CR.ssa 
 
28 
 
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.). 
No.  2012AP336-CR.ssa 
 
29 
 
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). 
No.  2012AP336-CR.ssa 
 
30 
 
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). 
No.  2012AP336-CR.ssa 
 
31 
 
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). 
No.  2012AP336-CR.ssa 
 
32 
 
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). 
No.  2012AP336-CR.ssa 
 
33 
 
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." 
No.  2012AP336-CR.ssa 
 
34 
 
¶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). 
No.  2012AP336-CR.ssa 
 
35 
 
 
¶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. 
No.  2012AP336-CR.ssa 
 
36 
 
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). 
No.  2012AP336-CR.ssa 
 
37 
 
¶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). 
No.  2012AP336-CR.ssa 
 
38 
 
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. 
No.  2012AP336-CR.ssa 
 
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¶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. 
No.  2012AP336-CR.ssa 
 
40 
 
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. 
No.  2012AP336-CR.ssa 
 
41 
 
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 
No.  2012AP336-CR.ssa 
 
42 
 
 
¶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. 
No.  2012AP336-CR.ssa 
 
43 
 
                                                                                                                                                             
(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 
No.  2012AP336-CR.ssa 
 
44 
 
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. 
No.  2012AP336-CR.ssa 
 
45 
 
¶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. 
No.  2012AP336-CR.ssa 
 
46 
 
¶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). 
No.  2012AP336-CR.ssa 
 
47 
 
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.   
No.  2012AP336-CR.ssa 
 
48 
 
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. 
No.  2012AP336-CR.ssa 
 
1 
 
APPENDIX 
 
No.  2012AP336-CR.ssa 
 
2 
 
 
 
No.  2012AP336-CR.ssa 
 
3 
 
 
 
No.  2012AP336-CR.ssa 
 
1