H. Michael Steinberg has 38+ years of experience practicing Colorado criminal law. Mr. Steinberg strives to stay current with the ever changing aspects of criminal law issues and updates resulting in his extensive knowledge of successful criminal defense as well as appellate work. He is also an active member of the National Association of Criminal Defense Lawyers, the Colorado Criminal Defense Bar Association, the Colorado Trial Lawyer's Association, and the Colorado and Arapahoe Bar Associations.
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The Impossible Defense of Impossibility in Colorado

The Impossible Defense of Impossibility in ColoradoBy H. Michael Steinberg Colorado Criminal Defense Lawyer


The complexities of successfully defending a Colorado criminal case require a thorough and comprehensive review of any and all of the possible legal defenses available for the case at hand. One of those defenses that should be explored is the defense of impossibility.

There are two kinds of impossibility-based defenses – factual impossibility and legal impossibility.

Helping the reader to understand the distinction between these two defenses is the purpose of this brief piece.

Legal impossibility can be asserted as a defense to such crimes as the commonly charged inchoate (unfinished) crime of attempt – Section 18-2-101.

On the other hand, with very few exceptions, factual impossibility is difficult to assert and is also legally barred as a defense to the primary crime against which it may be asserted, the crime of attempt under Colorado law.

Factual Impossibility

Factual impossibility means that the accused could not complete the crime they are attempting to commit because the accused’s comprehension of the facts of the case is skewed.

Factual impossibility is NOT a defense in Colorado and most other states.

The best example of factual impossibility is a “sting” operation such as the carefully staged sale of controlled substances using an undercover police agent as the buyer.

Another “sting” operation commonly used in economic crime cases where a false business for the sole purpose of catching a thief.  Yet another is the “To Catch a Predator” operation designed to locate and then lure and arrest internet predators.

A “sting ” operation, by definition, makes the crime the accused is attempting to commit, factually impossible.

Another example of factual impossibility is the person who intends to poison their spouse with the poison strychnine by adding the substance to their spouse’s morning coffee – but mistakenly uses sugar instead. The crime that was attempted – murder – was factually impossible because of the error, but the crime is nevertheless prosecuted in Colorado as an attempt to commit murder, an incomplete crime called an inchoate crime.

The “mens rea” or mental state for the crime is present but the act itself fails because of an error made by the accused …. no poison.

More examples – the person who believes that he or she has received stolen goods but again it is a police sting operation and the goods are not, in fact, stolen.

A pickpocket reaches into another’s breast pocket intending to steal only to find an empty pocket. The killer pulls the trigger to kill but the gun jams.

The Model Penal Code, (MPC) which serves as  a template for many states criminal codes, disallows factual impossibility as a defense in the attempted commission of a crime by defining attempt as “purposely engages in conduct which would constitute the crime if the attendant circumstances were as he believes them to be”

Model Penal Code § 5.01(1) (a)

Factual impossibility exists when the accomplishment of the crime is rendered impossible by:

(1) the physical inability of the actor,
(2) some inactive prevention, or
(3) the intervention of some natural force.

Sidebar: Compare the Mistake of Fact Defense

Factual impossibility is the opposite of a “mistake of fact” defense. A mistake of fact is where a person is unaware of circumstances that actually exist. Whereas factual impossibility is where the person believes that a circumstance exists when in reality, it does not exist.

Legal Impossibility

The legal impossibility defense means that the defendant believes the crime they have attempted to commit was illegal – but in fact – it is not illegal.

A person asserting a legal impossibility defense may actually complete all of his or her intended acts. They may have taken all of the steps to complete what they perceive is a crime, however, the completion of those intended acts do not meet the well-established elements of crimes enumerated in Colorado’s criminal code.

Crimes are committed when all of the elements, the parts that make up the crime itself, have been completed. Legal impossibility is a complete defense to a criminal investigation unless there exists, at the time of the acts in question, a law prohibiting those acts and making those acts a crime.

Even for the crime of attempt, a defendant who engages in conduct that he thinks is illegal but it is not, cannot be convicted of an attempt.

An example: if a person, a would-be trespasser, enters a public park at 10 pm thinking the park is closed when, in fact, the park actually closes at 11 pm that night. Under these facts, notwithstanding his intention, he cannot be convicted of the crime of attempted trespassing.

One law professor has described the difference between the two defenses this way:

Unless the objective sought is legally proscribed, the doing of it is not criminal nor is any conduct falling short of it a criminal attempt.

If the end sought is legally proscribed, the failure to attain it, because of the lack of a factual condition necessary to its attainment, is no defense.

Colorado Law of Attempt Expressly Provides that the Defense of Impossibility is Impossible

The Crime of Attempt – Section 18-2-101 – is a crime is commonly charged in Colorado. As noted above it is an inchoate or unfinished crime. It is in the context of the crime of attempt, the defense of impossibility is most often raised.

Colorado law has clarified that NEITHER defense is available to the charge of attempt

What follows is the relevant portion of the Colorado crime of attempt:

Section 18-2-101 – Criminal Attempt

(1) A person commits criminal attempt if, acting with the kind of culpability otherwise required for commission of an offense, he engages in conduct constituting a substantial step toward the commission of the offense. A substantial step is any conduct, whether act, omission, or possession, which is strongly corroborative of the firmness of the actor’s purpose to complete the commission of the offense.

Factual or legal impossibility of committing the offense is not a defense if the offense could have been committed had the attendant circumstances been as the actor believed them to be, nor is it a defense that the crime attempted was actually perpetrated by the accused.

Summary and Conclusion – The Impossible Defense of Impossibility in Colorado

To summarize this brief article:

Legal impossibility can possibly be a defense. It depends on the circumstances as more fully described above. Legal impossibility ONLY applies to those situations in which the intended act or acts, even if carried out, do not amount to a crime.

Factual impossibility is not a defense under Colorado law to the crime that has been attempted. The abolition of the defense of factual impossibility is codified in Colorado’s criminal attempt statute – reprinted above.

“A person charged with a crime requires the guiding hand of counsel at every step in the proceedings against him. Without it, though he be not guilty, he faces the danger of conviction because he does not know how to establish his innocence.”

United States Supreme Court – Powell v. Alabama, 287 U.S. 45, 69 (1932)

If you found any information I have provided on this web page article helpful please share it with others over social media so they may also find it. Thank you.

Never stop fighting – never stop believing in yourself and your right to due process of law.

BEST-STANDING-CHOICE-200x300ABOUT THE AUTHOR: H. Michael Steinberg – Email The Author at hmsteinberg@hotmail.com – A Denver Colorado Criminal Defense Lawyer – or call his office at 303-627-7777 during business hours – or call his cell if you cannot wait and need his immediate assistance – 720-220-2277. Attorney H. Michael Steinberg is passionate about criminal defense. His extensive knowledge of Colorado Criminal Law and his 38 plus years of experience in the courtrooms of Colorado may give him the edge you need to properly defend your case.