No, a convening authority cannot arbitrarily deny a defense-requested witness, and a denial without any written justification is a significant procedural error that can be challenged. An accused service member has a fundamental constitutional right to compel the attendance of witnesses on their behalf. While this right is not absolute—the witness’s testimony must be relevant and material to the case—a convening authority who denies a request must have a valid reason for doing so, such as the witness being truly unavailable or their testimony being merely cumulative of other evidence.
A military defense attorney who receives a denial without justification will immediately file a motion with the military judge assigned to the case. The motion will seek to compel the production of the witness. The attorney will first detail for the judge why the witness’s testimony is essential for a fair trial. They will then argue that the convening authority’s failure to provide any written rationale for the denial constitutes an abuse of discretion. This lack of justification suggests the denial was arbitrary and capricious, not based on a reasoned consideration of the request.
The military judge will then require the government to provide a reason for the witness’s unavailability. If the government cannot provide a legitimate and fact-based justification, the judge has the authority to grant the defense motion and order that the witness be produced at government expense. If the government is still unable or unwilling to produce an essential witness, the judge may grant a remedy to the defense, which could include dismissing the charges if the witness was critical to a fair trial.