Mobile Location Data Expert Witness
Expert analysis of phone location evidence — including historical cell-site location information (CSLI) and cell site analysis — distinguishing precision from accuracy, and whether the data proves device location, user location, account activity, or application activity.
⚖︎Led by Daniel B. Garrie, Esq. — Founder, Law & Forensics · Neutral, JAMS · Faculty, Harvard · retained or court-appointed in 100+ disputes. Same-day conflict checks on most new matters, capacity permitting.
Sources of Location Evidence
Many sources, very different reliability
Location evidence comes from sources that vary enormously in precision, accuracy, and meaning. Treating them interchangeably is a common — and serious — error.
GPS data
Satellite-derived coordinates and their stated accuracy radius.
Wi-Fi location
Position inferred from nearby networks — accurate at times, misleading at others.
Historical cell-site location information (CSLI)
Tower connections that indicate area, not a precise point.
Apple Significant Locations
On-device location history and what it actually records.
Google Location History
Account-level location timeline aggregated across signals.
Photo EXIF data
Embedded coordinates — and how easily they can be absent, altered, or copied.
App-specific logs
Location stored by individual apps under their own logic.
Map applications
Search, routing, and saved-place artifacts.
Ride-share & delivery apps
Trip and order artifacts that may reflect account, not device, activity.
The Central Distinction
Precision is not accuracy. Device is not user.
A coordinate can be precise and still wrong. And a location tied to a device or account does not, by itself, establish who was holding the phone or where a person was.
We also evaluate time-zone handling, which can shift a location's apparent time by hours and change the story entirely.
From Our Insights
Related reading
Mobile Evidence
Local vs. Cloud: Correctly Attributing Mobile and Digital Evidence
Read the analysis →Authentication
Metadata: The Forensic Backbone of Digital and Mobile Evidence
Read the analysis →Authentication
Authenticating Digital and Mobile Evidence in the Age of AI: Is Rule 901 Ready?
Read the analysis →FAQ
Frequently asked questions
How accurate is mobile phone location data?
Accuracy varies widely by source — GPS, Wi-Fi, and cell-site data have very different precision, and a single data point can be misleading. We distinguish precision from accuracy and explain what the data can actually establish.
Can cell-site (tower) data pinpoint someone's exact location?
Generally no. Cell-site records show which tower and sector served a connection, which can cover a broad and variable area. That data is often misused to imply a precision it does not have.
What location sources can be examined?
GPS, Wi-Fi, cell-site records, Apple Significant Locations, Google Location History, EXIF data in photos, and app logs — each with different reliability and interpretation.
Evaluate Phone Evidence Before Deposition
Location evidence in your matter?
Before location data is presented as fact, have it evaluated for source, precision, accuracy, and meaning.
Submitting a request does not create an attorney-client, expert, or consulting relationship. Do not send privileged or confidential materials until a conflict check is complete and an engagement agreement is in place.