      IN THE SUPERIOR COURT OF THE STATE OF DELAWARE

STATE OF DELAWARE,                     )
                                       )
      v.                               )         I.D. No. 1610003829
                                       )
STEVEN PIERCE,                         )
                                       )
            Defendant.                 )

                          Submitted: February 8, 2019
                            Decided: March 6, 2019


       Upon Defendant’s Motion in Limine to Exclude Expert Testimony
                                 DENIED



                                  OPINION




Annemarie H. Puit, Esquire, Matthew B. Frawley, Esquire, Jenna R. Milecki,
Esquire (argued), Department of Justice, Wilmington, Delaware, Attorneys for the
State.

Eugene J. Maurer, Jr., Esquire, Elise K. Wolpert, Esquire (argued), Wilmington,
Delaware, Attorneys for Defendant.

Rocanelli, J.
      This is a murder case. The State alleges that Defendant, Steven Pierce, shot

and killed his girlfriend, Heather Stamper, on July 9, 2016 in her Delaware City

home. The State proposes to introduce evidence tracking Defendant’s movements

for the 23-hour period before and after the approximate time of death. Defendant

seeks to exclude the Google Wi-Fi Location Data1 used to “geolocate” Defendant’s

cell phone on the grounds that the proposed evidence is not sufficiently reliable

under the Daubert standard and would mislead and confuse the jury. The State

argues that the technology at issue is reliable and would be helpful to the finder of

fact. The reliability of Google’s Wi-Fi Location Data is an issue of first impression

in Delaware.

                               PROCEDURAL HISTORY

      Defendant was indicted by the Grand Jury on December 5, 2016, and charged

with Murder in the First Degree and Possession of a Deadly Weapon During the

Commission of a Felony for the intentional murder of Heather Stamper. The case

was specially assigned to this Trial Judge. The trial was initially scheduled for

January 2018 but was rescheduled when Defendant retained new counsel who was

unavailable for that trial date.2 A new trial date was set for August 2018.




1
 See infra p. 3.
2
 The State did not oppose rescheduling the trial date. Defendant’s new counsel did
not enter his appearance until obtaining a new trial date.
                                          1
      On June 5, 2018, Defendant sought permission of the Court to file two

motions after the deadline imposed by the Court for pre-trial motions: a motion to

suppress certain evidence and a Daubert motion. The Court did not address the

motion to suppress because the parties reached an agreement that the State would

not use the challenged evidence in the State’s case-in-chief. Regarding the Daubert

motion, the Court conducted an office conference on June 28, 2018, at which time it

became clear that resolution of the novel issue involved would require that the trial

date be rescheduled again. Accordingly, the Court conducted a hearing on July 6,

2018 to address Defendant personally regarding his right to a speedy trial.

      The Court found that Defendant’s waiver of his speedy trial rights was

knowing, intelligent, and voluntary. By Order dated July 6, 2018, the Court granted

Defendant’s Motion to File a Daubert Motion Out-Of-Time, over the State’s

objection. A new Trial Scheduling Order was issued, setting the date for trial as April

2, 2019, and setting forth deadlines for discovery and briefing in connection with

Defendant’s Daubert motion.

      The Court conducted a Daubert hearing on November 27, 2018. In support of

the reliability of the State’s proposed evidence, the State presented the testimony of

Andrew Rist, an engineer, and Anthony Vega, a law enforcement officer. The State’s

two witnesses were subject to cross-examination by Defendant. The parties

submitted post-hearing briefs.

                                          2
                        THE TECHNOLOGY AT ISSUE3

      According to the United States Supreme Court, in 2018, there were 396

million cell phone service accounts in the United States.4 The High Court

emphasized that there are more cell phone accounts in the United States than there

are people.5 The most popular mobile devices have one of two operating systems

that control the functioning of the phone. For Apple phones, it is iPhone Operating

System (“iOS”) and for Google phones and many other phone manufacturers, it is

Android.

      Defendant’s phone was a MetroPCS phone with the Android operating

system. While there are similarities between Apple’s iOS and Google’s Android as

it relates to capturing user data, the technology at issue in this case involves location

data derived from communications between an Android mobile device and Google.

(The data is referenced herein as “Google Wi-Fi Location Data”). Specifically, the

subject of the Daubert motion in this case was the Wi-Fi-sourced geolocation

information associated with a unique Google account transmitted from the Android

operating system on Defendant’s mobile device and stored by Google.




3
  Unless noted otherwise, the Court’s discussion of the technology at issue is based
on the testimony and expert report of Andrew Rist. Daubert Hearing Tr. 5:21—
170:5 (J.A. 3); Andrew Rist Expert Rep. (J.A. 6).
4
  Carpenter v. United States, 138 S.Ct. 2206, 2211 (2018).
5
  Id.
                                           3
      A cell phone using the Android operating system serves as a data collection

device as it continuously collects and sends information to Google as “events”

approximately every 10-20 minutes. Meanwhile, other programs on the phone are

running, either actively by the cell phone user, or idly in the background. These

applications often rely upon Google Wi-Fi Location Data to customize information

sent by Google to the user.6 With each event, there are various categories of

information sent back to Google, including the device’s location history which is

comprised of GPS, cellular data, and recognized Wi-Fi signals. Google collects and

retains fairly detailed location information, including time-stamped barometer

readings to determine the device’s altitude, such as the floor within a building, and

Wi-Fi scans recorded with a time stamp for each location, noting latitude, longitude,

and estimated accuracy.

      Google Wi-Fi Location Data is not considered first-generation technology for

geolocation. Global Positioning System (“GPS”), a utility owned by the United

States government, uses satellites for positioning, navigation, and timing (“PNT”)

services.7 GPS receiver equipment is found in many mobile devices, including cell



6
  Countless applications rely upon the location of devices to provide cell phone users
with accurate local weather forecasts, driving directions, nearby restaurant
recommendations and reviews, the location of a lost device, news headlines, and a
myriad of other information.
7
  The Global Positioning System: GPS Overview, GPS. GOV,
https://www.gps.gov/systems/gps/.
                                          4
phones and vehicle navigation systems. Mobile devices exchange signals with GPS

satellites and use the transmitted information to calculate the user’s position.8 Under

open skies, “GPS-enabled smartphones are typically accurate to within a 4.9 meter

radius.”9 The accuracy of GPS can be compromised by many factors, including

satellite signal blockage due to tall buildings or trees, indoor or underground use,

and poor atmospheric conditions.10 Nevertheless, the reliability of GPS is well

established.11

      Another method for geolocation is Cell-Site Location Information (“CSLI”),

which refers to the information collected as a cell phone connects to nearby cell

towers.12 Although cell site records are generated by cell phone service providers for

commercial purposes, law enforcement agencies routinely request and use historical

CSLI for criminal investigatory purposes.13 With information from multiple cell

towers, a technique called “triangulation” is used to identify the location of a cell




8
  Id.
9
  GPS Accuracy, GPS.GOV,
https://www.gps.gov/systems/gps/performance/accuracy/.
10
   Id.
11
   See, e.g., United States v. Brooks, 715 F.3d 1069, 1078 (8th Cir. 2013); United
States v. Maynard, 615 F.3d 544, 562 (D.C. Cir. 2010).
12
   Carpenter, 138 S.Ct. at 2211.
13
   See Id. at 2223.
                                          5
phone, and by extension, the cell phone user’s approximate location within 50

meters.14 Like GPS, the reliability of CSLI is well established.15

      The underlying premise of Google Wi-Fi Location Data is the same as GPS

and CSLI. A Wi-Fi positioning system relies upon Wi-Fi signals to determine the

distance between the device and the signal access point (“AP”). Wi-Fi Access Points

are the devices that create a wireless local area network, such as a router in an office,

business, or home, by projecting a Wi-Fi signal to a designated area. Included in the

location data sent to Google by Android devices are Wi-Fi scans, which include a

list of the Wi-Fi APs the device could “see” at that particular time and location.16

Generally, in order for a device to see a Wi-Fi AP, the device will be within 150 feet

of a signal, much closer than with cell tower positioning. Google collects and stores

the locations and strength of Wi-Fi APs, identified by their Media Access Control

(“MAC”) address, in order to locate mobile devices. When multiple signals are in

range, Google Location Services uses multilateration to identify the device location,

with more signals providing a more accurate location.


14
   See Id. at 2219.
15
   Taylor v. State, 23 A.3d 851, 856 (Del. 2011) (finding no abuse of discretion
where, after a Daubert hearing, the trial court allowed expert testimony on cell phone
data mapping, a recognized process deemed reliable by the law enforcement
community); State v. Thompson, I.D. No. 1602016732 (Del. Super. May 30, 2017)
(TRANSCRIPT) (admitting historical cell site evidence and denying Defendant’s
Daubert Motion without a hearing).
16
   Andrew Rist explains that when cell phones “see” access points, this means that
the phone is in the presence of one or more Wi-Fi signals.
                                           6
      Wi-Fi APs were first mapped by Google as part of its Street View program

using vehicles which physically drove around with Wi-Fi receivers to collect street

level pictures and record Wi-Fi signals, a process known as “wardriving.” This

mapping method was the subject of the Zandbergen paper published in 2004.17 Since

that time, Wi-Fi AP locations have been mapped and maintained by Google through

a process called “crowdsourcing,” whereby information sent back to Google by

individual cell phones is used to identify the location of Wi-Fi APs.18 Crowdsourcing

allows more data to be collected more frequently and provides for greater accuracy

as more users contribute to data regarding the location of Wi-Fi APs.

                    PROPOSED EVIDENCE
        PLACING DEFENDANT AT OR NEAR MURDER SCENE19

      Defendant’s cell phone (“Target Device”) was seized on July 9, 2016, the day

Heather Stamper was found dead in her home in Delaware City, Delaware. The




17
   Paul A. Zandbergen, Accuracy of iPhone Locations: A Comparison of Assisted
GPS, WiFi and Cellular Positioning (2009).
18
   An example of crowd-sourcing technology is a navigational system that uses real-
time information collected from individual drivers to notify other local drivers of
traffic, motor vehicle accidents, potholes, and law enforcement speed monitoring
and to re-route a driver to a more efficient route using the crowd-sourced
information. Parmy Olson, What Waze Adds to Google: A View from Waze’s CEO
(June 13, 2013).
19
   Unless noted otherwise, the Court’s discussion of the proposed evidence placing
Defendant at or near the murder scene is based on the testimony and report of
Anthony Vega. Daubert Hearing Tr. 170:12—223:15 (J.A. 3); Anthony Vega Rep.
(J.A. 11).
                                         7
phone number for the Target Device matches the phone number that Defendant

identified as his own phone number during his July 9, 2016 interview with the police.

      Through a search warrant,20 Detective Csapo of the Delaware State Police

obtained Google location data for the Target Device, International Mobile

Equipment Identity (“IMEI”) number 359696076323056 (“Target IMEI”).21

Google responded to the search warrant in accordance with the Federal Electronic

Communications Privacy Act22 and provided the following information for each

time-stamped event for the time period from 6:53 p.m. on July 8, 2016, through 5:49

p.m. on July 9, 2016: identity of account as piercesteve91@gmail.com; date;

Universal Time Coordinated (UTC); date and time in Eastern Daylight Time (EDT)

using military time; latitude; longitude; map display radius in meters; map display

radius in miles; source (GPS or Wi-Fi); and device tag.

      Agent Vega analyzed the data associated with the Target IMEI and mapped

the geolocation of the Target Device by plotting the latitude, longitude, and

estimated radius of GPS and Wi-Fi coordinates, showing those locations using



20
   To satisfy the Fourth Amendment, a search warrant is required based on a finding
of probable cause for a government search of a cell phone. Carpenter, 138 S.Ct. at
2221. There is no challenge in this case to the search warrants by which the
surveillance video, Defendant’s cell phone data, or Google Wi-Fi Location Data was
acquired by the State.
21
   An IMEI is a unique identifier for a cell phone made of numerical digits that
identify the make, model, and serial number for each mobile device.
22
   18 U.S.C. § 2703.
                                         8
Google Earth. In addition to the Google Wi-Fi and GPS location data, Agent Vega

used surveillance video to prepare a PowerPoint presentation tracking Defendant.

Time-stamped photographs taken from video surveillance correspond to the Google

Wi-Fi Location Data and GPS data to show Defendant and/or the Target Device

travelling throughout this time period: in Heather Stamper’s vehicle; driving on the

streets of Delaware City and heading towards New Castle; at a check-out counter in

a New Castle liquor store; driving towards Delaware City; in the vicinity of Heather

Stamper’s home; travelling towards and in the vicinity of Defendant’s mother’s

home; with Defendant’s mother entering a convenience store; and in various other

locations nearby during the next day.

      STANDARD FOR ADMISSIBILITY OF EXPERT TESTIMONY

      The Delaware Supreme Court has adopted the Daubert standard to determine

the admissibility of expert testimony.23 Under this standard, the Court asks whether:

(i) the witness is “qualified as an expert by knowledge, skill, experience, training or

education;” (ii) the evidence is relevant and reliable; (iii) the expert’s opinion is

based upon information “reasonably relied upon by experts in the particular field;”

(iv) the expert testimony will “assist the trier of fact to understand the evidence or




23
 See Eskin v. Carden, 842 A.2d 1222, 1231 (Del. 2004) (citing Daubert v. Merrell
Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993)).
                                          9
to determine a fact in issue;” and (v) the expert testimony will not create unfair

prejudice or confuse or mislead the jury.24

      When assessing the second factor of the Daubert standard—the reliability of

the expert’s opinion—trial courts consult a non-exclusive list of four more questions:

(1) whether the opinion at issue is susceptible to testing and has been subjected to

such testing; (2) whether the opinion has been subjected to peer review; (3) whether

there is a known or potential rate of error associated with the methodology used and

whether there are standards controlling the technique’s operation; and (4) whether

the theory has been accepted in the scientific community.25

                    THE TECHONOLOGY IS RELIABLE
                   AND WILL ASSIST THE FACT-FINDER

      As the gatekeeper, the trial judge’s role “is to make certain that an expert,

whether basing testimony upon professional studies or personal experience, employs

in the courtroom the same level of intellectual rigor that characterizes the practice of

an expert in the relevant field.”26 Neither the parties nor the Court has identified a

reported decision applying the Daubert standard involving testimony by a computer




24
   Id. at 1227 (quoting Cunningham v. McDonald, 689 A.2d 1190, 1193 (Del.1997)).
25
   Sturgis v. Bayside Health Ass’n Chartered, 942 A.2d 579, 584 (Del. 2007).
26
   Rodriguez v. State, 30 A.3d 764, 769 (Del. 2011) (quoting Kumho Tire Co. v.
Carmichael, 526 U.S. 137, 152 (1999)).
                                          10
scientist or engineer addressing reliability of Google Wi-Fi Location Data.27

Accordingly, this Court’s reasoned analysis regarding the reliability of Google Wi-

Fi Location Data is not informed by rulings of other trial courts.

     (i)     The State’s expert witnesses are qualified as experts by knowledge,
             skill, experience, training and education.

           Defendant does not challenge Andrew Rist as an expert in the computer

science field. Rist has an undergraduate degree in mechanical engineering and a

master’s degree in manufacturing engineering, and has worked as an engineer for




27
   The State has identified state courts in Virginia, California, and Colorado, and a
federal court in New York, that have permitted FBI Agents to offer testimony based
on Google Wi-Fi Location Data, including where admissibility of the evidence was
not challenged by the defendant, and one instance where a trial court in New York
disallowed such evidence using the Frye standard. United States v. Pizarro, 17-CR-
151, at 1319, 1337 (S.D.N.Y.) (TRANSCRIPT) (finding FBI CAST agent to be
qualified as an expert in historical cell site analysis and admitting Google Wi-Fi
Location Data without challenge); Commonwealth of Virginia v. Rolland Ellisworth
Anderson, Cases No. CR17-4909, 4910, 4911, 4913-00F (Va. Cir. Ct. Jan. 8, 2019)
(ORDER) (denying the defendant’s motion in limine to preclude the commonwealth
from presenting data reports and testimony concerning Google location services);
People of the State of Colorado v. Glen Law Galloway, Case No. 16CR2749, at 2
(Colo. Dist. Ct. Mar. 6, 2018) (ORDER) (denying motion to preclude expert opinion
testimony concerning Google Wi-Fi Location Data because the defendant’s
objections go to the weight of the evidence and not its admissibility); The People of
the State of New York v. Johnny Oquendo, Indictment No. 16-1154, Index No.
254831, at 2 (N.Y. Sup. Ct. Oct. 26, 2017) (citing Frye v. United States, 293 F. 1013,
1014 (D.C. Cir. 1923)) (precluding evidence of Google Wi-Fi Location Data where
the testifying witness was neither a scientist nor an engineer); Commonwealth of
Virginia v. Nathanial Howard Moone III, CR-16000297-00, CR-16000298, at 11
(Va. Cir. Ct. June 8, 2016) (TRANSCRIPT) (admitting Google Wi-Fi Location Data
without objection).
                                          11
Oracle Corporation for more than 20 years.28 Since 2008, Rist has been an

Interoperability Architect reporting to Oracle’s Chief Technology Officer, and his

recent professional focus has been collection and interpretation of communications

data, particularly data sent back to Google by cell phones.

       Defendant also does not challenge Anthony Vega as an expert witness. Agent

Vega is a Detective with the Philadelphia Police Department’s Major Crimes Unit,

Task Force Officer with the Federal Bureau of Investigation (“FBI”), and member

of FBI’s Cellular Analysis Survey Team (“CAST”). Agent Vega testified regarding

his training as a law enforcement officer generally and with respect to cell phone

technology.

       Andrew Rist has the knowledge, skill, experience, training and education to

be qualified as an expert in the field of computer technology and specifically with

respect to Google Wi-Fi Location Data. Anthony Vega has the knowledge, skill,

experience, training, and education to be qualified as an expert in the use of computer

technology for criminal investigations. Thus, the first factor of the Daubert standard

is satisfied.




28
  The Court rejects Defendant’s argument that a long-running feud between Google
and Oracle undermines Rist’s credibility. To the contrary, as an employee of Oracle,
Rist has no incentive to inflate the reliability or exaggerate the accuracy of Google’s
technology.
                                          12
     (ii)         Google’s Wi-Fi Location Data is relevant and reliable.29

            The relevance of the evidence is not challenged. However, Defendant

challenges the reliability of the methodology underlying Google Wi-Fi Location

Data.

            (1)      The use of Google’s Wi-Fi Location Data to geolocate an
                     individual based on signals sent to Google by that
                     individual’s cell phone is susceptible to testing and has been
                     subjected to such testing by the State’s expert, Andrew Rist.

            By employing an industry standard testing method, Rist and his team at Oracle

constructed a device, referred to as a “test rig,” to understand the communications

sent back and forth between Google and the Android operating system. The device

consists of a bag containing 20 cell phones, each with an associated Google account,

which operates as a “man-in-the-middle” exploit to observe the signals sent by the

devices to Google.30 For a period of approximately two years, Rist has tested and

confirmed the accuracy of the Google Wi-Fi Location Data and other

communications data by analyzing communications between the phones in the test

rig and Google Application Programming Interface (“API”) locations and various

Google-owned domains. Over the two years of testing, Oracle has collected



29
   Unless noted otherwise, the Court’s discussion of the technology at issue is based
on the testimony and expert report of Andrew Rist. Daubert Hearing Tr. 5:21—
170:5 (J.A. 3); Andrew Rist Expert Rep. (J.A. 6).
30
   The test rig includes both Android and Apple phones. The Oracle team has also
studied the information that is sent back to Apple from iPhones.
                                               13
approximately 70,00 location data points from the devices in the test rig. Rist

testified that the Google Wi-Fi Location Data is accurate and reliable.

      In addition to Oracle’s general testing of Google Wi-Fi Location Data

collection through the use of the test rig, Rist deployed the test rig specifically in the

vicinity of Heather Stamper’s home to determine the strength of Wi-Fi signals in

that area.31 Rist concluded that the density of Wi-Fi signals for the Google Wi-Fi

Location Data produced by Google in response to the search warrant in this case is

reliable to identify the location of the Target Device within approximately 100 feet.32

Rist also reviewed the report prepared by Agent Vega and concluded that the

location information for the Target Device located in Agent Vega’s PowerPoint

presentation are consistent both generally with the data revealed by Rist’s general

testing and also consistent with Rist’s specific findings using the test rig in the area

around Heather Stamper’s home.




31
   Defendant’s challenge to the two-year gap between the data produced by Google
for the Target Device and the data collected by Rist’s test rig can be addressed by
cross-examination. These challenges go to the weight of the evidence and not the
admissibility. Daubert, 509 U.S. at 596 (“Vigorous cross-examination, presentation
of contrary evidence, and careful instruction on the burden of proof are the
traditional and appropriate means of attacking shaky but admissible evidence.”).
32
   Rist was not provided with the raw data produced by Google in response to the
search warrant for the Target Device. Rather, the data collected and relied upon by
Rist was gathered independently of the data produced by Google and utilized in
Agent Vega’s Powerpoint presentation.

                                           14
      Accordingly, the accuracy of the Google Wi-Fi Location Data has been tested.

The Court is satisfied with the testing generally regarding the reliability of the

Google Wi-Fi Location Data and specifically as determinative of the reliability of

Google Wi-Fi Location Data for the Target Device.

      (2)    Google Wi-Fi Location Data has been subjected to peer
             review in the relevant scientific community.

      The accuracy of Wi-Fi location data is the subject of computer science

publications and blogs. For example, a 2015 publication from the Technical

Information Center of Denmark found that “APs can be very efficiently geolocated

in a way that covers a large majority of individuals’ mobility patterns.”33 The

reliability of Wi-Fi positioning systems is supported by this study which finds “Wi-

Fi scans containing at least one visible AP can be used for discovering the location

of the user, with a typical spatial resolution on the order of the tens of meters.”34 The

Court is satisfied that the relevant scientific community is in agreement regarding

the reliability of Google Wi-Fi Location Data. Accordingly, the accuracy of Google

Wi-Fi Location Data has been subjected to peer review in the relevant scientific

community.35




33
   Piotr Sapiezynski, et al., Tracking Human Mobility Using WiFi Signals 9 (2015).
34
   Id. at 3.
35
   The pace of technology advances within the computer science field results in peer
review different from the peer review process in other sciences, such as life sciences.
                                           15
      (3)   Google Wi-Fi Location Data is verified by other mechanisms
            of determining geolocation of the Target Device.

      A mobile device will switch between GPS and Wi-Fi based on the strength of

available signals to improve the accuracy of a location reading.36 The mobile device

prefers Wi-Fi because it uses less power and is available in settings where GPS

signals are more limited, such as indoors, but GPS is used to supplement the

available Wi-Fi signals. Data for GPS and Wi-Fi APs are both included in the Google

location data provided in response to the search warrant for the Target Device.

Importantly, Google Wi-Fi Location Data is consistent with the fixed GPS location

data.37 Where fixed GPS location data is not available, time stamps from video

surveillance footage substantiate the reliability of the Wi-Fi-sourced readings.

Accordingly, the accuracy of Google Wi-Fi Location Data is verified by other

mechanisms of determining the geolocation of the Target Device.

      (4)   The reliability of Google Wi-Fi Location Data has been
            accepted in the marketplace and has also been accepted in
            the community as a whole.

      Accurate geolocation of a mobile device is an important part of Google’s

business plan for the Android operating system.38 Users of Google’s applications


36
   Any questions regarding the strength of each Wi-Fi signal goes to the weight and
not the admissibility of the evidence. Daubert, 509 U.S. at 596.
37
   Defendant is not challenging the accuracy of the GPS data and concedes its
accuracy.
38
   The Carpenter Court noted the business purposes of collecting accurate CSLI data
in its discussion of the reliability of that data. Carpenter, 138 S.Ct. at 2212.
                                        16
do not pay a fee; Google’s applications are free of charge to the user. Individuals

everywhere rely upon this technology every day in myriad ways to access a variety

of information based on their own location.39 Merchants pay fees to Google for

access to information collected by Google about users of Google applications,

including user location. Merchants use this location information provided by Google

to promote products, often targeting advertisements to specific geographical

locations. For example, Google can send advertisements to users who are near a

certain restaurant. Accordingly, the reliability of Google Wi-Fi Location Data is

accepted by the community as a whole, and in the marketplace.

      Therefore, the Court has assessed the second factor of the Daubert standard:

the reliability of the Google W-Fi Location data has been tested; it has been subject

to peer review in the relevant scientific community; it is substantiated by other

mechanisms of geolocation; and it is accepted by the community as a whole. The

Court finds that the methodology underlying Google Wi-Fi Location Data is reliable.

Thus, the second factor of the Daubert standard is satisfied.




39
   The information collected by Google for any given device with a Google account
is accessible at maps.google.com/timeline, although the information available at this
site is less detailed than the information produced by Google in response to the
search warrant in this case. Daubert Hearing Tr. 27:11—28:5 (J.A. 3).
                                         17
     (iii)   Google Wi-Fi Location Data is widely accepted in the computer
             science industry and reasonably relied upon by law enforcement.

         It is acceptance by the scientific community, rather than by the courts, that is

identified under Daubert as an indicator of a technique’s reliability.40 Google Wi-

Fi Location Data is widely accepted as reliable in the computer science community.

In addition, Google Wi-Fi Location Data is generated for commercial purposes,

which was recognized by Carpenter as an indicia of reliability.41 Furthermore, law

enforcement relies upon GPS, historical cell cite analysis,42 and, more recently,

Google Wi-Fi Location Data to place an individual at a specific location at a specific

time. Thus, the third factor of Daubert is satisfied.

     (iv)    Expert testimony based on the Google Wi-Fi Location Data will
             assist the jury to understand the evidence and to determine a fact
             in issue.

         Expert testimony must help the fact finder understand the evidence or

determine a fact in issue.43 The jury in this case will be charged with determining

whether the State has established beyond a reasonable doubt that Defendant

murdered Heather Stamper. Google Wi-Fi Location Data associated with

Defendant’s own cell phone will assist the jury in understanding Defendant’s


40
    United States v. Reynolds, 626 Fed.Appx. 610, 616 (6th Cir. 2015) (citing
Daubert, 509 U.S. at 593-94).
41
   As recognized by the United States Supreme Court in Carpenter, cell-site records
are generated for commercial purposes. Carpenter, 138 S.Ct. at 2217.
42
   See Id. at 2218.
43
   Cunningham, 689 A.2d at 1193.
                                            18
approximate location before, during, and after the murder. Thus, the fourth factor

of Daubert is satisfied.

      (v)      The expert testimony will not create unfair prejudice or confuse or
               mislead the jury.

            The technology at issue will not confuse or mislead the jury. Indeed, “cell

phones and the services they provide are ‘such a pervasive and insistent part of daily

life’ that carrying one is indispensable to participation in modern society.”44 The

technology, once explained, will be well within the jury’s capability to comprehend

and weigh. According to Defendant, the State has sufficient evidence, referencing

GPS and surveillance footage specifically, without also using Google Wi-Fi

Location Data, which according to Defendant, is duplicative and will mislead and

confuse the jury. The Court is satisfied that the probative value of the Google Wi-Fi

Location Data substantially outweighs the danger of unfair prejudice, confusion of

the issues, misleading the jury, or needlessly presenting cumulative evidence.45

Thus, the fifth factor of Daubert is satisfied.




44
     Carpenter, 138 S.Ct. at 2220 (citing Riley v. California, 573 U.S. 373, 385 (2014)).
45
     D.R.E. 403.
                                             19
                                   CONCLUSION

      The evidence is relevant and the experts presented by the State are qualified

by knowledge, skill, training and education. The State has established by a

preponderance of the evidence that the Google Wi-Fi Location Data is reliable: the

Google Wi-Fi Location Data at issue is susceptible to testing and has been subjected

to such testing; it has been subjected to peer review in the relevant scientific

community; it is verified by other mechanisms of determining geolocation of the

Target Device; it is accepted in the computer science/high tech community; and it is

widely relied upon in the marketplace and by the community as a whole. Moreover,

Google Wi-Fi Location Data will assist the trier of fact to understand the evidence

and to determine a factual issue. Finally, the evidence will not create unfair prejudice

or confusion.

      NOW, THEREFORE, the Defendant’s Motion in Limine to Exclude

Expert Testimony is hereby DENIED.

      IT IS SO ORDERED.

                                               Andrea L. Rocanelli
                                               ______________________________
                                               The Honorable Andrea L. Rocanelli




                                          20
