DC Superior Court Judge Michael Ryan heard testimony from an expert witness, who the defense in a fatal shooting case seeks to exclude, during a motions hearing on April 21.
D’Andre Montgomery, 20, is charged with conspiracy, felony murder while armed with aggravating circumstances, premeditated first-degree murder while armed, assault with intent to kill while armed, attempt to commit robbery while armed, four counts of possession of a firearm during a crime of violence, carrying a pistol without a license outside of a home or business, and unauthorized use of a vehicle during a crime of violence for his alleged involvement in a Dec. 16, 2023 shooting that fatally injured 28-year-old Kenneth Barksdale on the 1200 block of 44th Place, SE.
Montgomery’s co-defendant, Eric Sheffield, 21, faces the same charges as Montgomery for his alleged involvement in the same incident and Kevin Hider, 20, is also charged with first-degree murder while armed.
Montgomery’s attorney, Sylvia Smith, filed a number of motions in advance of the trial, including a Daubert motion which seeks to exclude the testimony of a GPS technology expert on various technical grounds. The requests will be considered by DC Superior Court Judge Danya Dayson. She was originally assigned the case and continues to evaluate many of the motions. .
Prosecutors called the expert, vice president of Sentinel Offender Services, the company that manufactured the GPS monitor worn by Montgomery at the time of the incident. The vice president testified that the GPS technology is 98 percent accurate within the accuracy range. Accuracy is determined by comparing the “actual location” to the “location reported.”
On cross-examination, Smith questioned the vice president on the source of the 98 percent figure. The vice president testified that this is an estimate based on his experience and “various unpublished studies,” adding that the 98 percent figure is not published.
The witness also testified about a March 2026 report testing the accuracy of the GPS technology in the ankle monitors that his company manufactures. In order to conduct the test, he placed two ankle monitors in an open field during “optimal conditions.” He concluded that both monitors fell within the accuracy range provided by the chipset, or electronic components, in the monitor. Smith questioned the expert’s methodology and the technology’s lack of third-party review.
The vice president also testified that he is familiar with the process to determine accuracy but is not aware of “specific algorithms” that are used to determine the accuracy range. The chipset is manufactured by a different company that has not shared their “secret formula” with the public.
In addition to Smith’s Daubert motion, Judge Ryan also reviewed three other motions filed by the defense including one regarding the use of body worn camera and autopsy photos by the prosecution. Another motion pertained to whether statements in an evidence document will be admissible during trial.
Parties are slated to reconvene April 22 for Judge Ryan to rule on the motions.
