The impossibility defense can only be applied for incomplete offenses (i.e. attempt). There are two types of impossibility defenses: factual impossibility and legal impossibility.
- Factual Impossibility – the defendant could not complete the crime because…; this defense seeks to negate the actus reus. The defendant is arguing that something got in the way of his completion of the crime. Generally, a factual impossibility defense is not permitted.
- Legal Impossibility – even if the defendant’s conduct was or is completed, it is not illegal. Here, the court looks at the elements of the offense and finds that not all of the elements are present. Even if the defendant thought his conduct was wrong, a legal impossibility defense will be valid.
Example: Defendant burns down his own house in order to collect the insurance proceeds. Under common law, arson required the burning of the dwelling of another. Therefore, it is legally impossible to find the defendant guilty of arson.
Mistake of Law is not a valid defense to a general intent crime. Even if the defendant’s mistake was reasonable, mistake of law is not a valid defense. (See People v. Marrero). The only exception is if a statute proscribing the defendant’s conduct has not been reasonably made available or if the defendant recently relied on a statute or judicial decision that was recently held unconstitutional.
However, under a specific intent crime, the defendant’s mistake of law is a valid defense whether reasonable or unreasonable. (See Cheek v. United States).
Compare to Mistake of Fact Defense
More Helpful Information: List of General Intent and Specific Intent Crimes
Under the Common Law, if the crime only requires general intent, the defendant’s mistake must be reasonable for mistake of fact to be a valid defense. If the crime is a specific intent crime, the defendant’s mistake can be reasonable or unreasonable. This reasonableness is first a legal conclusion, then it goes to the jury to determine whether or not the mistake was reasonable.
Under the MPC Section 2.04, the defendant’s mistake must go towards negating the mens rea required for the crime. If the crime only requires general intent, the mens rea is going to default to recklessness.
See Regina v. Prince for an example of mistake of fact.
Compare to Mistake of Law
Case Name: M’Naghten’s Case
Citation: 8 Eng. Rep. 718 (1843)
Facts: M’Naghten was indicted for the murder of the secretary to the prime minister when he sought to assassinate the prime minister. M’Naghten had many prominent medical experts that provided testimony that he suffered from acute insanity. The jury returned a verdict of “not guilty, on the ground of insanity.”
The discussion surrounds questions that were asked by the House of Lords to the English judiciary about when a jury would be charged with determining the defense of insanity. The House of Lords wanted to have a better policy on when the defense of insanity could be used.
Legal Answer: The House of Lords determined that “every man is to be presumed to be sane” until the “contrary be proved to their satisfaction.” The House required that to establish a defense on the ground of insanity, it must be clearly proved that, at the time of the committing of the act, the party accused was laboring under such a defect of reason, from disease of the mind, as not to know the nature and quality of the act he was doing; or if he did know it, that he did not know he was doing what was wrong – this should not be a question of “actual knowledge of the law of the land” but the presumption that everyone must be taken conclusively to know it, without proof that he does know it.
Case Name: State v. Toscano
Citation: 74 N.J. 421 (1977)
Facts: Toscano was charged with conspiracy to obtain money by false pretenses (through insurance fraud). At trial, Toscano testified that he was under duress after Leonardo, the conspiracy organizer, made threats to Toscano and his wife. The trial judge did not allow the jury to consider the Toscano’s evidence of duress.
State’s argument: Toscano was not under duress because there was not a threat of impending death or serious bodily harm that was imminent, present, and pending. Toscano could have sought police protection and help.
Defendant’s argument: The trial court should have allowed Toscano’s evidence of duress because it was because of the threats to him and his wife that he was involved in the conspiracy to begin with.
Holding: Remanded for new trial.
Reasoning: Toscano provided a factual basis that he and his wife were threatened with physical violence if he refused to assist in the fraudulent scheme. A jury may have found that the threats induced a reasonable fear.
Case Name: People v. Goetz
Citation: 68 NY 2d 96 (1986)
Facts: Goetz was indicted on attempted murder, assault, and other charges for having shot and wounded four youths on a New York City subway train. The youths had approached Goetz and asked him for $5. Goetz had previously been mugged on the subway and believed these youths were going to mug him. The defendant then shot all four of the youths from left to right with his unlicensed pistol. The fifth bullet in the gun he used on one of the boys who “seem[ed] to be all right” so Goetz gave him “another.” None of the youths died but the boy who was shot twice was left paralyzed and with brain damage.
State’s argument: In evaluating the defendant’s self defense claim, the question is whether the defendant’s conduct was that of a reasonable man in the defendant’s situation.
Defendant’s argument: The use of the phrase “reasonably believes” in the penal code means that the analysis is from the point of view of the defendant and whether he reasonably believed he needed to act in self defense.
Holding: The state’s reading of the statute is proper.
Reasoning: The use of the word “reasonable” before belief shows that the drafters wanted to adopt an objective standard. The defendant’s own perceptions could completely exonerate him from any criminal liability.