Yes. A co-accused who has resolved his own case through a plea agreement can be called to testify during the sentencing phase of the remaining accused’s court-martial. There is no rule of military justice that disqualifies a witness simply because he was once charged in the same matter or because his cooperation was part of a deal. What the law does is regulate how that testimony comes in, what it may be offered to prove, and how the defense may expose the witness’s motives.
Why the Witness Is Competent
In military practice, the general presumption is that every person is competent to be a witness. A prior or current accused status, a guilty plea, and a cooperation agreement go to credibility and weight, not to competency. So the threshold question, can the co-accused take the stand at all, is answered in the affirmative. The harder and more important questions concern the scope and purpose of the testimony at sentencing.
The Sentencing Framework
Military sentencing is governed by the presentencing procedure in Rule for Courts-Martial 1001. The Government’s evidence in aggravation is limited by RCM 1001(b)(4) to evidence of aggravating circumstances directly relating to or resulting from the offenses of which the accused has been found guilty. That phrase is the key limitation. A cooperating co-accused may testify about the circumstances of the offense, the accused’s role, the planning, the impact, and similar matters, but only to the extent the testimony actually relates to or results from the offenses of conviction. Trial counsel cannot use the cooperator as a vehicle to introduce unrelated bad acts that fall outside that aggravation boundary, and the military judge polices the line.
Because the relevant accused has already been found guilty by the time sentencing begins, whether by plea or by findings, the cooperator’s testimony is typically directed at the gravity of the proven conduct rather than at re-litigating guilt. The Military Rules of Evidence still apply during sentencing, including the balancing test that allows a judge to exclude evidence when its probative value is substantially outweighed by unfair prejudice or needless presentation of cumulative material.
The Cooperation Agreement Is Fair Game
The single most important practical point for the defense is that the witness’s deal is squarely subject to scrutiny. When a co-accused has entered into a plea agreement that requires or contemplates testimony, that agreement and the surrounding circumstances are relevant to the witness’s credibility and may be brought before the sentencing authority. Cross-examination may probe the witness’s potential bias and motive to shade testimony in the Government’s favor. Permissible inquiry typically includes whether the witness had a pretrial or plea agreement, whether he pleaded guilty, whether he entered into a stipulation of fact, whether he received or sought immunity, whether continued cooperation was a condition of his deal, and whether clemency or a sentence benefit was still pending or unresolved at the time he testified. A witness who stands to gain from satisfying the prosecution has an obvious incentive that the factfinder is entitled to consider.
This right to expose bias has constitutional dimensions. The Confrontation Clause protects an accused’s ability to cross-examine adverse witnesses, and that protection extends to revealing the cooperator’s motive to curry favor. At the same time, the right is not unlimited. A military judge may place reasonable limits on cross-examination and may, for example, preclude inquiry into a single specific term of the agreement without violating confrontation rights, so long as the defense is otherwise permitted adequate inquiry into the witness’s bias and motive through other questions about the deal. The governing principle is that the defense must have a meaningful opportunity to show why the witness might be motivated to testify favorably for the Government, not that it may explore every clause without limit.
Immunized Testimony and Related Wrinkles
Sometimes the cooperating co-accused testifies under a grant of immunity rather than, or in addition to, a plea agreement. Immunity affects the witness’s own exposure and must be disclosed, because it bears directly on motive and on the candor calculus the factfinder performs. Counsel should also be alert to the terms of any stipulation of fact that accompanied the cooperator’s own plea, since those terms can constrain what he may say and can be used to test consistency. If the witness deviates from his own stipulation or earlier statements, that inconsistency is classic impeachment material.
What This Means for the Remaining Accused
The takeaway is twofold. First, the prosecution is generally entitled to call a co-accused who has pleaded out, and that witness may give aggravation testimony in sentencing within the RCM 1001(b)(4) boundary, subject to the ordinary rules of evidence. Second, the defense holds a powerful counterweight: full and pointed cross-examination on the existence and terms of the deal, the guilty plea, any stipulation, any immunity, and any pending or unresolved clemency, all of which expose the witness’s incentive to please the Government. The strength of such testimony rises and falls on the witness’s credibility, and credibility is exactly what the cooperation arrangement puts in issue.
Because the admissibility of specific testimony, the precise scope of aggravation, and the permissible limits on cross-examination are all fact dependent and litigated in real time before the military judge, the remaining accused should be represented by counsel experienced in court-martial sentencing practice to preserve confrontation objections, frame the impeachment, and argue the weight the cooperator’s testimony deserves.
Disclaimer
This article is provided strictly for general educational and informational purposes. It is intended to explain how the Uniform Code of Military Justice (UCMJ), the Rules for Courts-Martial, the Military Rules of Evidence, and related military administrative processes work as a matter of public legal education. It does not constitute legal advice, a legal opinion, or a recommendation about any particular case, and it is not a substitute for advice from a qualified military defense attorney who can evaluate the specific facts and command, service, and jurisdictional circumstances involved.
Reading this article, or contacting any website on which it appears, does not create an attorney-client relationship between the reader and any law firm, attorney, or author. Every court-martial, nonjudicial punishment action, administrative separation, and security-clearance matter turns on its own facts, the charged articles, the convening authority, the service branch, and the evidence, and outcomes vary widely from one case to another.
Military law also changes over time. The Military Justice Act of 2016 (effective January 1, 2019) and subsequent National Defense Authorization Acts renumbered and rewrote many punitive articles, revised the Article 32 preliminary hearing, and altered sentencing, clemency, and appellate procedures. Statutes, regulations, executive orders, the Manual for Courts-Martial, and decisions of the service Courts of Criminal Appeals and the Court of Appeals for the Armed Forces may have been amended, superseded, or reinterpreted after this article was written, and article numbers or procedures cited here may have changed.
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