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Expert Testimony in Florida Criminal Trials: Can Cell Phone Mapping Evidence Be Used Against You?
In Florida criminal trials, cell phone mapping evidence is increasingly used to place defendants near the scene of a crime. Prosecutors rely on call detail records and tower data to create digital maps that suggest a person’s location based on cell site activity. But how accurate is this evidence, and can it be challenged? Recent Florida case law has upheld the admissibility of such expert testimony—even when the testifying detective doesn’t understand the software’s internal algorithm or error rate. As courts lean toward accepting this digital evidence, it’s critical to understand both its power and its limitations. This page explores the legal standards, challenges, and defense strategies related to cell phone mapping and expert testimony in Florida criminal courts.
By W.F. “Casey” Ebsary, Jr.
Board Certified Criminal Trial Lawyer
Tampa, Florida | 
(813) 222-2220
View My Bio | Contact Now
Introduction: What Is Cell Phone Mapping Evidence?
Expert testimony in Cell phone mapping evidence is often used in criminal cases to suggest a defendant’s location at the time a crime occurred. Prosecutors use it to argue that your phone connected to a specific cell tower near the scene.
But how reliable is this information? Do detectives and expert witnesses truly understand the technology they’re presenting?
In a recent appellate decision, the court held that it was not an error to allow a detective to testify about a cell site coverage map placing a defendant near a crime scene. Even though the detective did not know the underlying algorithm or the error rate of the mapping software, the court found that his experience and training made the evidence admissible. This precedent has major implications for anyone accused based on digital cell phone data.
Frequently Asked Questions About Cell Phone Mapping in Florida Criminal Cases
Cell phone mapping is the process of using call detail records (CDRs), tower locations, and specialized software to estimate where a mobile device was at a given time. This includes:
Historical cell site location information (CSLI)
Computer-generated cell site maps
Timestamps from call logs or text messages
These maps are based on tower coverage, not GPS coordinates.
Yes. Florida courts have allowed testimony from detectives and other law enforcement personnel who can demonstrate:
Knowledge of how the software works in practice
Training in cell phone analysis and data interpretation
Experience using the technology in investigations
Even if the witness does not understand the software’s internal algorithms, their testimony may still be admissible under § 90.702, Fla. Stat.
Read the Statute on Justia
Not necessarily. Under the Daubert standard, Florida judges evaluate:
Whether the method is scientifically valid
Whether it’s been tested or peer-reviewed
The error rate (if known)
Whether it’s generally accepted in the field
A recent ruling confirmed that experts don’t need to know the underlying code or algorithm, as long as the output is reliable and the expert can explain how it’s used in the field.
Daubert v. Merrell Dow Pharmaceuticals
Cell mapping is not exact science. It’s more like estimating a location, not pinpointing it.
📉 Here’s How Cell Phone Mapping compares to GPS:
| Feature | Cell Site Mapping | GPS Tracking |
|---|---|---|
| Accuracy | 0.5–2+ miles radius | Within a few feet |
| Based on | Tower ping triangulation | Satellite positioning |
| Real-Time? | No (historical) | Yes (real-time possible) |
| Used by Police? | Common | Less common unless installed |
| Challenged in Court? | Frequently | Rarely |
More Frequently Asked Questions About Cell Phone Mapping
Courts have ruled that the absence of an exact error rate does not make the evidence inadmissible—especially if the detective:
Underwent specialized training
Used standard investigative software
Explained how the data fit the investigation
Courts can rule it would be unrealistic and unworkable to expect every expert who uses technology with a computer component to testify to the workings of the algorithm.
These individuals may qualify: Detectives trained in digital forensics, FBI CAST team analysts, and Telecom engineers or consultants. The key is that the witness must understand and explain the mapping software’s application, even if they don’t understand the full engineering behind it.
Yes—and you absolutely should. Common strategies include:
Daubert challenges to the method’s reliability
Cross-examining the officer about software limitations
Highlighting that the phone’s owner may not be the user
Showing the coverage map includes large areas Florida Rule of Criminal Procedure 3.190(h) – Motions to Suppress
Not anymore. In Carpenter v. United States, the U.S. Supreme Court ruled that accessing historical CSLI without a warrant violates the Fourth Amendment. If police got your records without a judge’s approval, a skilled defense attorney may be able to suppress the evidence.
Carpenter v. U.S. (2018) on Justia
Contact an attorney immediately. You need someone who understands:
Digital forensics and telecom protocols
The Daubert standard
How to question expert testimony
How to file motions to exclude unreliable evidence Call me at (813) 222-2220 or send a message today.
Yes. I’ve helped clients fight—and beat—serious criminal charges where prosecutors relied on shaky digital evidence.
I understand the technical flaws behind cell mapping
I’ve successfully cross-examined digital “experts”
I’ve had evidence excluded that would have led to wrongful convictions
See My Bio and Case Experience Request a Free Case Evaluation
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Key Legal Resources
§ 90.702, Fla. Stat. Expert Testimony Rules Justia
Rule 3.190(h), Fla. R. Crim. P. Motion to Suppress Florida Courts
Testimony Reliability Standard, Daubert v. Merrell Dow Justia
Warrant Required for CSLI, Carpenter v. United States Justia
Call a Digital Evidence Defense Attorney Today
Don’t let misunderstood technology decide your future. If you’re facing criminal charges involving cell phone location data, cell tower mapping, or expert testimony you don’t trust, you need a lawyer who understands both the law and the tech.
I’m W.F. Casey Ebsary Jr., a Board Certified Criminal Trial Lawyer with a track record of defending clients in high-tech cases.
Schedule Your Confidential Consultation Now »
Or call: (813) 222-2220
Related Pages on Cell Phone Usage
Crime Mapping Systems in Tampa Bay – Keeping Score(Opens in a new browser tab)
I, Spybot(Opens in a new browser tab)
Cell Phone Tower Data Admissible(Opens in a new browser tab)
Defense Attorney on Cell Phone Search | Evidence Suppressed(Opens in a new browser tab)