A map with a red dot on it is not a location. It is an inference built on carrier records, sector assumptions, and a chain of reasoning that is rarely written down. Since December 1, 2023, Rule 702(d) has required whoever offers that analysis to show, more likely than not, that the method was reliably applied to the facts of this case. A cell site analysis review is a $2,750 flat fee: an independent examiner's critique memo plus the cross-examination questions to go with it.
The state produced call detail records, an analyst mapped them, and now there is an exhibit showing your client's phone near the scene. The exhibit looks authoritative. The underlying reasoning usually is not in the record at all.
This review puts a court-qualified digital forensics examiner on the other side's analysis before you have to question its author. What records did they actually receive, and for what date range? Which fields did they use, and which did they quietly ignore? Does the map show a coverage area, or does it show a conclusion drawn on top of one? Where did a sector become a point?
The review is performed by a court-qualified digital forensics examiner. The practice is led by Eric L. Waldrep, who brings 19 years in digital forensics and 27 years in law enforcement, holds the MCFE (Magnet Certified Forensics Examiner) credential, and serves as a U.S. State Department ATA Cyber Mentor, with casework in federal and state courts. These analyses get read the way an examiner reads any evidence: for method, for documentation, and for the distance between what the data supports and what the report claims.
Send the analysis and the underlying records, confirm scope on a free consultation, and receive the memo and question set on a stated date. The engagement runs remotely, serving attorneys nationwide.
Most pages in this corner of the market blur the line. This one states it, because an expert who cannot say where their expertise ends is the easiest witness in the room to take apart.
That work belongs to an RF engineer or a CAST-trained analyst. If your matter needs it, you will hear so on the first call, before you retain anyone. Knowing which expert you actually need is worth a free consultation on its own.
Courts have drawn this line for well over a decade, and the 2023 amendment to Rule 702 sharpened it. The proponent of expert testimony must now demonstrate, by a preponderance of the evidence, that each requirement is met, including subsection (d):
"the expert's opinion reflects a reliable application of the principles and methods to the facts of the case." Fed. R. Evid. 702(d), as amended effective December 1, 2023
In United States v. Evans, 892 F. Supp. 2d 949 (N.D. Ill. 2012), the court held a Rule 702 hearing on cell site testimony and split the difference in a way that still frames these fights. The agent was qualified to explain how cellular networks operate, and that testimony came in. The "granulization" theory used to narrow the phone's position, along with the estimated coverage ranges built on it, was excluded as unreliable, in part because it rested on the assumption that a phone connects to the closest tower.
That assumption is the recurring problem. It is also the one most often left unstated. A phone associates with the sector offering the best overall connection, which weighs signal quality and network congestion alongside proximity. The FCC's own consumer guidance on coverage notes that terrain, structures, and weather all affect which site serves a call. A handset sitting in one place across five successive calls can register on more than one antenna.
Two questions worth putting to any analyst, on the record, before the map goes to the jury:
Which training does the witness actually hold? The FBI's Cellular Analysis Survey Team certification runs to more than 500 hours, and by the Bureau's own account fewer than 100 agents hold it. The FBI also offers a separate two-day Basic Historical Cell Site Analysis course for state and local investigators. Both are legitimate. They are not the same qualification, and Rule 702(a) asks which one is behind the opinion being offered.
Was there any drive testing? CAST's own practice contemplates using survey equipment to establish a sector's true coverage. When an analyst maps coverage without measuring it, the map is a model, not an observation. That distinction belongs in the record, and it is a subsection (d) question, not a jury argument.
Separately, and on the suppression side rather than the reliability side: Carpenter v. United States, decided June 22, 2018, held that acquiring historical cell site location information is a Fourth Amendment search, and that seven days or more of it requires a warrant. How the records were obtained is counsel's issue, not an examiner's. It is noted here only because the production paperwork is part of what this review reads.
Each area gets checked against the analysis itself, its exhibits, and whatever underlying carrier production you can obtain.
What training stands behind the opinion, and whether it reaches as far as the opinion does. A two-day course and a 500-hour certification support very different testimony.
The date range produced against the date range analyzed. Selective windows, missing days, and the calls that fall conveniently outside the exhibit.
A serving sector is an area, often a large and irregular one. The review marks every place that area quietly became a dot, an arc, or an overlap the records do not support.
Whether it was made, whether it was disclosed, and whether anything in the record supports it for these calls, this network, and this terrain.
Carrier records do not all speak in local time. Normalization errors move events by hours and are among the easiest defects to demonstrate once they are found.
A background data registration is not a call, and a phone in a pocket generates them without its owner touching it. Treating the two alike inflates a timeline and misstates intent.
Google Location History, Apple significant locations, app geolocation, Wi-Fi joins, photo EXIF. Device artifacts routinely qualify or contradict a tower narrative, and they are squarely digital forensics work.
Records never requested, alternative explanations never ruled out, error and uncertainty never acknowledged. The silences get catalogued too.
The work product is two documents, written for the trial team rather than for another examiner.
First, a written critique memo in plain English. It walks the analysis finding by finding: what the records actually establish, what the exhibit claims, and where those two part company, with each weakness tied to the page, exhibit, or record range where it lives.
Second, a set of deposition or cross-examination questions built from those weaknesses. Not generic expert-deposition boilerplate: questions keyed to this analysis, sequenced to commit the analyst to a method and to the limits of their training before reaching the gaps.
As soon as the analysis is disclosed. It is most useful before you depose the analyst and before Daubert or motion deadlines, while there is still time to act on what it finds. If a deadline is close, say so on the first call and you will get a plain answer on whether the timeline works.
You know the cost before you send the records, and the initial consultation is free. The full fee schedule for every other service is on the rates page.
Flat fee, defined scope. If the matter later calls for a rebuttal report or testimony, that work is quoted and billed separately.
Hourly consulting for work outside the flat-fee scope, quoted before it begins.
Flat rate per device. Testimony and all other services are listed on the fee schedule.
Some reviews end with the memo. Others surface enough that counsel wants a response on the record. Both paths are scoped and billed separately, so the flat fee stays a flat fee.
A formal report responding to the analyst's opinions, built for disclosure and confined to the scope above. If the critique memo identifies grounds for one, you will hear it plainly, with a quote before any work begins. See forensic reports and declarations.
Deposition and trial testimony as a retained expert, available nationwide with travel as needed, on digital forensics and the reliability of the analysis reviewed. Terms are on the expert witness page.
Cell site exhibits show up far outside criminal court, and the review works the same way regardless of which table you sit at.
The questions to ask of any digital forensics report before you depose its author. Free, no strings.
The flat fee, the scope line, turnaround, and the materials the review needs.
Send the analysis and the underlying records, confirm scope on a free consultation, and have the critique memo and question set in hand before the deposition. A written fee agreement comes before any work begins.
Free initial consultation · $2,750 flat fee, defined scope · Serving attorneys nationwide from Addison, Alabama
Tell us what the matter involves and we will respond personally. Initial consultations are free, and nothing you send here is a retention.
