Background
In the early morning hours of September 11, 2016, two men robbed a BP gas station in Howard County, Maryland at gunpoint. Fingerprint evidence identified James Brown as a suspect, and a review of Brown’s cell phone records led police to Lionel Lee Prince. The State charged Prince with multiple offenses arising from the robbery.
At Prince’s second trial in February 2018, Detective Christian Kim testified as a lay witness about cell site data drawn from T-Mobile call detail records for both Brown’s and Prince’s phones. The records, in spreadsheet form, listed the street address, city, state, and zip code of each cell tower the phones communicated with at given times. Detective Kim read those tower locations to the jury. Prince’s trial counsel did not object to this testimony. Counsel did, however, successfully object when Detective Kim attempted to go further — interpreting the data to opine that the two phones were likely in close proximity to each other and were traveling north after the robbery. The court sustained those objections and struck the interpretive testimony. The jury convicted Prince of first-degree assault, robbery with a dangerous weapon, conspiracy to commit robbery with a dangerous weapon, and firearm possession with a disqualifying conviction.
Prince filed a petition for postconviction relief arguing, among other grounds, that trial counsel was ineffective for failing to object to the entirety of Detective Kim’s cell site data testimony — not just the interpretive portions. The postconviction court agreed, concluding that all cell site data testimony required a qualified expert and that counsel’s failure to object to the foundational location testimony was deficient performance prejudicing Prince. The court granted a new trial. The State appealed.
The Court’s Holding
The Appellate Court of Maryland reversed, holding that the postconviction court erred in granting Prince a new trial. The central question was whether Detective Kim’s lay testimony about cell tower locations was admissible without expert qualification. The court held it was. Because Detective Kim simply read the street addresses of cell towers as they already appeared in the T-Mobile call detail records — information the jury itself could have read directly from those same records admitted into evidence — his testimony did not require specialized knowledge, skill, or training beyond the ken of the average juror. It therefore did not cross the line into inadmissible lay opinion on a subject requiring expert qualification under Maryland Rules 5-701 and 5-702.
The court distinguished this testimony from the kinds of cell site data testimony Maryland courts had previously required expert qualification for — such as using software to plot phone locations on a map, analyzing signal strength, or drawing inferences about a phone’s sector or direction of travel. None of that occurred here. Trial counsel had, in fact, successfully objected to Detective Kim’s interpretive testimony about proximity and direction of travel, and the court struck that testimony. What remained was the unobjected-to tower-location testimony, which amounted to reading addresses from a business record already in evidence.
Because the unobjected-to testimony was admissible, counsel’s failure to object to it was not erroneous and therefore not deficient performance under the first prong of Strickland v. Washington, 466 U.S. 668 (1984). The court noted that a failure to object to admissible testimony cannot constitute ineffective assistance, and it need not reach the prejudice prong of Strickland. The court also clarified that, because the relevant facts were undisputed, it was empowered to make its own reasonableness determination on de novo review rather than remanding for factual findings the postconviction court had not made.
Key Takeaways
- A detective’s lay testimony about which cell towers a defendant’s phone communicated with — where the testimony consists of reading street addresses already printed in the carrier’s call detail records — is admissible without expert qualification under Maryland Rules 5-701 and 5-702.
- Expert qualification is required for cell site data testimony only when it involves interpretation, analysis, or inference beyond the understanding of an average juror, such as plotting locations with software, analyzing signal sectors, or opining on direction of travel.
- Failing to object to admissible testimony is not deficient performance under Strickland; ineffective assistance cannot be premised on counsel’s failure to raise an objection that would not have been sustained.
- When the underlying facts of a postconviction reasonableness inquiry are undisputed and the postconviction court made no factual findings, the appellate court may conduct its own reasonableness analysis on de novo review rather than remanding.
Why It Matters
This decision draws a practical line in the ongoing debate over cell site data evidence: not all testimony touching on cell towers triggers the expert-witness requirement. When a law enforcement officer does nothing more than relay location information already contained in a carrier’s business records — information a juror could read for themselves — no specialized knowledge is required and no expert designation is needed. Defense counsel and prosecutors in Maryland now have clearer guidance on where the admissibility boundary falls and, by extension, when a failure to object can and cannot support an ineffective assistance claim.
The ruling also reinforces an important principle for postconviction litigation: the foundation for an ineffective assistance claim based on a failure to object must be that the testimony was actually objectionable. Where the challenged testimony was lawfully admitted, the claim fails at the deficient-performance stage without reaching prejudice. For practitioners, the case underscores the importance of carefully parsing which portions of cell site testimony cross into expert territory — and objecting precisely and strategically, as Prince’s own trial counsel did with the interpretive portions of Detective Kim’s testimony.