United States v. Poynter, Jr.: Fourth Circuit Re-Affirms the Reliability of Historical Cell-Site Analysis and Clarifies Plain-Error Review of Rule 702/403 Challenges

1. Introduction

The Fourth Circuit’s unpublished opinion in United States v. Keith Poynter, Jr., No. 23-4540 (4th Cir. June 25 2025), addresses the admissibility of (1) expert testimony based on historical cell-site location information (CSLI) and (2) co-conspirator testimony referencing prior robberies. Although the decision is non-precedential, it crystallises two practical rules:

• Historical CSLI testimony that satisfies Daubert is “generally reliable” and therefore unlikely to be deemed plainly erroneous when admitted without objection.
• Challenges to potentially prejudicial testimony under Rules 401 and 403 must be timely raised; failure to object triggers a demanding plain-error standard that is seldom met in the presence of strong corroborating evidence.

2. Background of the Case

Between 10–22 December 2019, a series of armed robberies unfolded across Baltimore, Maryland. Keith Poynter, Jr. and several accomplices—including Tiffany Gardner and Benjamin Bunn, Jr.—were indicted on multiple federal counts, ranging from Hobbs Act robbery to firearm offences. A federal jury convicted Poynter on eight counts, and the District Court (Gallagher, J.) imposed a 312-month sentence.

On appeal, Poynter attacked two evidentiary rulings:

1. Admission of the Government’s expert on historical CSLI.
2. Admission of co-conspirator Gardner’s testimony describing Bunn’s previous robberies and his practice of hiring others.

Because trial counsel raised no contemporaneous objection to either item, only plain-error review applied.

3. Summary of the Judgment

A per curiam panel (King, Rushing & Floyd, JJ.) affirmed the convictions and sentence, finding:

• No plain error in admitting the CSLI expert’s testimony—the methodology was sufficiently explained, widely accepted, and relevant.
• No plain error in admitting Gardner’s testimony—the evidence was relevant under Rule 401, not unduly prejudicial under Rule 403, and even any error would be harmless given overwhelming proof of guilt.
• Even had error existed, it did not affect Poynter’s substantial rights because other evidence (eyewitness identifications, surveillance videos, additional co-conspirator testimony) was compelling.

4. Analysis

4.1 Precedents Cited

• United States v. Walker, 32 F.4th 377 (4th Cir. 2022) – Framework for plain-error review of unobjected-to evidentiary rulings.
• United States v. Ojedokun, 16 F.4th 1091 (4th Cir. 2021) – Defines “plain” and “affecting substantial rights.”
• United States v. Oceanic Illsabe, Ltd., 889 F.3d 178 (4th Cir. 2018) – “Jumps off the page” articulation of plain error.
• United States v. Hill, 818 F.3d 289 (7th Cir. 2016) – Leading appellate approval of historical CSLI expert analysis.
• United States v. Morgan, 45 F.4th 192 (D.C. Cir. 2022) – Noted for the remark that courts “generally find historical cell-site analysis reliable.”
• Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579 (1993) – Supreme Court’s seminal decision on scientific expert admissibility under Rule 702.
• United States v. Potter, 927 F.3d 446 (6th Cir. 2019) – On relevancy of prior bad acts even where Rule 404(b) not invoked.
• United States v. Chaudhri, __ F.4th __, 2025 WL 1037524 (4th Cir. Apr. 8 2025) – Balancing under Rule 403.
• United States v. Carthorne, 726 F.3d 503 (4th Cir. 2013) – Explains “settled law” criterion in plain-error analysis.
• In re Lipitor, 892 F.3d 624 (4th Cir. 2018) – Emphasises reliability & relevance as Daubert’s core.

4.2 Court’s Legal Reasoning

Step 1 – Plain-Error Framework. The panel reiterated the four-part test: (1) error, (2) plainness, (3) effect on substantial rights, and (4) discretionary remedial action based on fairness and integrity of the proceeding (citing Cohen, 888 F.3d 667).

Step 2 – Historical CSLI Expert.

• The expert described her methodology and data sources (provider switch logs, tower maps).
• She conceded limitations (phone often—but not invariably—connects to the closest tower), displaying methodological transparency.
• Field testing and error-rate testimony are helpful but not dispositive under Daubert; reliability existed because the method is “generally accepted” (Hill; Morgan).
• No Supreme Court or Fourth Circuit authority labels such testimony inadmissible; therefore any error could not be “plain.”

Step 3 – Gardner’s Co-Conspirator Testimony.

• Relevancy: Prior acts by Bunn were circumstantial proof of Bunn’s modus operandi, and hence probative of whether Bunn hired Poynter for the charged robberies.
• Rule 403: Even if evidence implied Poynter’s involvement in earlier robberies, it was not more sensational than the charged conduct; prejudice did not substantially outweigh probative value (citing Chaudhri).
• Harmlessness: Given corroborating eyewitnesses, surveillance video, and other testimony, any evidentiary misstep would not have affected the verdict.

4.3 Impact on Future Litigation

• Strategic Obligation to Object. The decision underscores how failure to lodge a contemporaneous Rule 702 or Rule 403 objection all but forecloses appellate relief under plain-error review.
• CSLI Admissibility. Counsel should anticipate that, at least within the Fourth Circuit, historical cell-site analysis will ordinarily be deemed reliable if the expert explains methodology and data-source integrity, even without live field testing.
• Bad-Acts Testimony. Litigants should frame objections under Rule 404(b) in addition to Rules 401/403 when prior conduct surfaces; omission of 404(b) arguments may weaken an appellate challenge.
• Unpublished but Persuasive. Although non-binding, the opinion will likely be cited for its detailed recitation of the “plain-error plus Daubert” intersection and may influence district judges evaluating CSLI experts.

5. Complex Concepts Simplified

• Historical Cell-Site Location Information (CSLI): Cellphone carriers log which tower (and sometimes sector) a phone connects to during calls, texts, or data sessions. Mapping those logs to tower coordinates allows experts to infer—within a variable radius—the handset’s position at a given time.
• Daubert Standard (Rule 702): Courts act as “gatekeepers,” admitting expert testimony only if (1) the expert is qualified, (2) the methodology is reliable (tested, peer-reviewed, error rate known, generally accepted), and (3) the testimony fits the facts at issue.
• Plain-Error Review: Applied when no objection is lodged at trial. The appellant must show a clear (plain) legal or factual mistake that probably changed the outcome, and the appeals court must additionally opt to correct it.
• Rule 401 vs. Rule 403: Rule 401 asks, “Does this evidence make a fact of consequence more or less probable?” – a low threshold. Rule 403 balances probative value against dangers such as unfair prejudice, confusion, or waste of time.

6. Conclusion

United States v. Poynter, Jr. is a cautionary tale on the importance of timely objections and an instructive reaffirmation that historical CSLI analysis, when properly explained, meets the reliability and relevance yardsticks of Daubert. The Fourth Circuit’s reasoning elucidates how, absent settled contrary authority, admitting such evidence cannot constitute “plain error.” Likewise, testimony regarding related bad acts will survive Rule 401/403 scrutiny when its probative value dovetails with the charged conspiracy. In the broader legal landscape, the opinion fortifies the growing consensus that CSLI evidence is here to stay, and it reminds practitioners that procedural default can be as fatal as substantive weakness.