What Is the Article 31 Warning and How Does It Differ from the Miranda Warning?
On this page
The Article 31(b) warning is the UCMJ’s rights advisement: before anyone subject to the UCMJ questions an accused or suspect in an official law-enforcement or disciplinary capacity, that person must state the nature of the accusation, advise of the right to remain silent, and warn that any statement may be used at court-martial. The key difference from Miranda is the trigger. Miranda applies to custodial interrogation by police; Article 31(b) applies to official questioning of a suspect by a person subject to the UCMJ, in custody or not, and it requires telling the suspect what the suspicion is.
The text of Article 31(b)
No person subject to this chapter may interrogate, or request any statement from, an accused or a person suspected of an offense without first informing him of the nature of the accusation and advising him that he does not have to make any statement regarding the offense of which he is accused or suspected and that any statement made by him may be used as evidence against him in a trial by court-martial.
Source: 10 U.S.C. § 831(b).
Article 31 has four parts:
- (a) no person subject to the UCMJ may compel anyone to incriminate himself or to answer a question whose answer may tend to incriminate him;
- (b) the warning requirement quoted above;
- (c) no one may be compelled to make a statement or produce evidence before a military tribunal if it is not material to the issue and may tend to degrade him;
- (d) “No statement obtained from any person in violation of this article, or through the use of coercion, unlawful influence, or unlawful inducement may be received in evidence against him in a trial by court-martial.”
Side by side
| Article 31(b) | Miranda | |
|---|---|---|
| Source | Statute (UCMJ, enacted 1950, effective May 31, 1951) | Constitution, Miranda v. Arizona (1966) |
| Who must warn | Any person subject to the UCMJ, and their knowing agents | Law enforcement |
| Trigger | Interrogating or requesting a statement from an accused or suspect, in an official law-enforcement or disciplinary capacity | Custodial interrogation |
| Custody required | No | Yes |
| Must state the accusation | Yes | No |
| Counsel | Not in Article 31 itself; M.R.E. 305(c)(2)-(3) give counsel rights in custodial interrogation and after preferral, and a valid waiver must affirmatively decline counsel (M.R.E. 305(e)(1)) | Warning of the right to counsel |
When the duty arises
Interrogation means “any formal or informal questioning in which an incriminating response either is sought or is a reasonable consequence of such questioning” (M.R.E. 305(b)(2)). A “person subject to the code” includes, for the warning requirement, “a knowing agent of any such person or of a military unit” (M.R.E. 305(b)(1)).
Official capacity. The Court of Appeals for the Armed Forces explained in United States v. Jones, No. 14-0071 (C.A.A.F. July 21, 2014), that warnings are required if the questioner “is participating in an official law enforcement or disciplinary investigation or inquiry,” as opposed to having a personal motivation, determined by “assessing all the facts and circumstances at the time of the interview to determine whether the military questioner was acting or could reasonably be considered to be acting in an official law-enforcement or disciplinary capacity.” Jones expressly rejected the earlier second prong that asked whether the person questioned perceived the inquiry as more than casual conversation, making the test objective.
What that means in practice:
- A superior who calls in a subordinate suspected of misconduct and asks about it is the kind of questioner the rule addresses; no arrest or closed door is needed.
- A purely personal conversation between peers, with no investigative or disciplinary purpose, falls outside the duty.
- A person with no authority over the suspect can still be a “knowing agent” if acting for investigators.
The warning operates alongside other investigation-stage protections, such as limits on searches described in how search and seizure rules apply in the military. A step-by-step account of what happens when investigators call someone in appears in rights of the accused during military investigation.
Counsel rights during questioning
Article 31 does not mention counsel. The Military Rules of Evidence supply the counsel rules:
- Custodial interrogation. If a suspect in custodial interrogation requests counsel, statements made after the request, and evidence derived from them, are inadmissible unless counsel was present (M.R.E. 305(c)(2)).
- After preferral of charges. If an accused against whom charges have been preferred is interrogated about those charges by anyone acting in a law enforcement capacity, and the accused requests counsel or already has counsel, statements are inadmissible unless counsel was present (M.R.E. 305(c)(3)).
- Invoking rights. “If a person chooses to exercise the privilege against self-incrimination, questioning must cease immediately”; if the person invokes counsel in those settings, questioning must stop until counsel is present (M.R.E. 305(c)(4)).
- Free counsel. Counsel requested under the rule is provided “at no expense to the person and without regard to the person’s indigency” (M.R.E. 305(d)).
Waiver. A waiver must be free, knowing, and intelligent; no written waiver is required, but the suspect “must affirmatively acknowledge that he or she understands the rights involved, affirmatively decline the right to counsel, and affirmatively consent to making a statement” (M.R.E. 305(e)(1)). After a custodial request for counsel, a later waiver is invalid unless the prosecution shows the suspect initiated the communication or was not continuously restricted between the request and the waiver (M.R.E. 305(e)(3)(A)).
What happens when the warning is skipped
A statement obtained in violation of Article 31 or M.R.E. 305 “is involuntary” and is treated under M.R.E. 304 (M.R.E. 305(a), (c)(1)). On a timely defense motion, an involuntary statement and evidence derived from it are inadmissible (M.R.E. 304(a)). The motion must be made before the plea is entered, or it is waived unless the judge permits it later for good cause (M.R.E. 304(f)(1)).
There are two limited uses. Such a statement may be used only “to impeach by contradiction the in-court testimony of the accused”, or “in a later prosecution against the accused for perjury, false swearing, or the making of a false official statement” (M.R.E. 304(e)).
A separate safeguard applies to any confession or admission: it may be considered on guilt only if independent evidence has been admitted “that would tend to establish the trustworthiness of the admission or confession” (M.R.E. 304(c)(1)).
Questioning by civilian or foreign officials
When federal, state, or local civilian officials question a person subject to the UCMJ, the right to warnings and the validity of any waiver are determined “by the principles of law generally recognized in the trial of criminal cases in the United States district courts” (M.R.E. 305(f)(1)). Article 31 and Fifth and Sixth Amendment warnings are not required in an interrogation by foreign officials abroad unless U.S. military personnel or U.S. officials conduct, instigate, or participate in it; a foreign statement is still inadmissible if obtained through coercion, unlawful influence, or unlawful inducement (M.R.E. 305(f)(2)).
Sources
- 10 U.S.C. § 831, Article 31, Compulsory self-incrimination prohibited (Cornell LII)
- U.S. Court of Appeals for the Armed Forces, court brochure, History (CAAF)
- United States v. Jones, No. 14-0071 (C.A.A.F. 2014), opinion (CAAF)
- Manual for Courts-Martial, United States (2024 ed.), Military Rules of Evidence 304 and 305
This article is general information about military law, not legal advice for any individual case.