Often yes. Under Article 80 of the Uniform Code of Military Justice, a service member can be convicted of an attempt even when a mistake about the facts made the intended crime impossible to complete. The classic example is the member who enters the wrong room intending to commit an offense, only to find no one there or nothing to take. That kind of mistake is a factual impossibility, and factual impossibility is not a defense to attempt. What matters is the member’s intent and the step taken toward the crime, not whether external facts made success achievable. A different kind of mistake, however, can defeat an attempt, so the distinction has to be drawn carefully.
The elements of attempt under Article 80
Article 80 makes it an offense to attempt to commit any offense under the code. It has four elements: an overt act, done with the specific intent to commit a particular offense, that amounts to more than mere preparation, and that apparently tends to effect the commission of the intended offense. Military law applies the substantial step standard to the more than preparation element, requiring conduct that strongly corroborates the accused’s criminal intent. The focus throughout is on what the accused intended and did, which is why a mistake about the surrounding facts usually does not help the accused.
Factual impossibility is not a defense
Factual impossibility exists when the accused intended to commit a crime and took a substantial step toward it, but some fact unknown to the accused made completion impossible. The member who breaks into the wrong room intending to steal, finding it empty, has still attempted larceny. The member who reaches into a pocket to steal a wallet that is not there has still attempted larceny. The member who tries to buy contraband from a person who turns out to be an undercover agent has still attempted the drug offense. In each case the accused had the specific intent, took a substantial step, and would have completed the crime had the facts been as the accused believed them to be. The law treats that as a punishable attempt because the accused has demonstrated both the intent and the dangerous conduct that attempt liability targets.
Why the wrong room scenario fits this rule
The wrong room hypothetical is a textbook factual impossibility. Suppose a member intends to enter a specific room to steal property or to confront a particular person, but mistakenly enters the wrong room and the object of the intended crime is not there. The member intended the offense and took a substantial step toward it. The only reason the crime was not completed is a mistaken belief about which room contained the target. That mistake does not negate intent. The member meant to commit the offense and acted on that intent, so the attempt is complete the moment the substantial step occurred, regardless of whether the room held what the member expected.
When a mistake of fact does defeat liability
A mistake of fact helps the accused only when it negates the specific intent that attempt requires. If the member’s mistaken belief means the member never actually intended to commit the offense, there is no attempt, because the specific intent element is missing. For example, a member who enters a room genuinely believing it is their own assigned space, with no intent to commit any offense, has not attempted anything, because there was no criminal purpose to begin with. The line is between a mistake about whether the crime can succeed, which does not excuse, and a mistake that means the member never had the criminal intent at all, which does.
Legal impossibility and the limits of attempt
There is also a separate doctrine, legal impossibility, which can be a defense. Legal impossibility arises when the act the accused intended to do would not be a crime even if fully carried out. If a member believes certain conduct is prohibited and tries to do it, but the conduct is in fact lawful, there is no offense to attempt, because the law does not criminalize a wish to break a nonexistent rule. This is distinct from the wrong room situation, where the intended act, theft, would plainly be a crime if completed. The mistake there goes to the facts, not to whether the conduct is legally an offense.
What the prosecution must prove
To convict of attempt where the accused misunderstood the facts, the government must prove the specific intent to commit the particular offense, an overt act that was a substantial step toward it, that the act was more than mere preparation, and that the act apparently tended to effect the crime as the accused believed the circumstances to be. The government does not have to prove that completion was actually possible. The defense, in turn, will look for a way to show that the accused lacked the specific intent, because that is the element a factual mistake almost never defeats but a genuine absence of criminal purpose does.
Bottom line
A service member can be punished for attempt even when a mistake about the facts, such as entering the wrong room, made the intended crime impossible to complete, because factual impossibility is not a defense under Article 80. The decisive questions are whether the member had the specific intent to commit the offense and took a substantial step toward it. A mistake helps only when it shows the member never had that criminal intent, or when the intended act would not have been a crime at all, which is legal impossibility. A simple mistake about where the target was or whether success was achievable does not excuse the attempt.
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.
For these reasons, no reader should act or decline to act based on this content without first consulting a licensed attorney experienced in military justice about their own situation. The author and publisher make no warranty, express or implied, as to the accuracy, completeness, timeliness, or current applicability of the information provided, and disclaim any liability for any action taken or not taken in reliance on it. If you are facing investigation, charges, or an adverse administrative action, time limits may apply, and you should seek qualified counsel promptly.