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