Mistake of Fact as a Defense

The defense of mistake of fact is used when a defendant is accused of committing a particular crime and the defendant admits that he or she committed another crime, which other crime is different from the particular crime and is not a lesser-included offense of the particular crime. The defense is based on the defendant's belief that he or she was committing another crime, which crime is less serious than the crime with which the defendant is charged.

An example of the defense of mistake of fact is when a defendant is charged with possession of a controlled substance or drugs and the defendant claims that he or she believed that he or she was in the possession of stolen property. The defendant claims that he or she does not have the necessary intent to be convicted of the offense of possession of a controlled substance because he or she thought that he or she was in the possession of stolen property.

The defense of mistake of fact does not allow a defendant to evade all criminal liability for an offense. The defendant can be convicted of the offense with which the defendant believed that he or she was committing, even if the defendant was not charged with the offense and even if the offense is not a lesser-included offense of the offense with which the defendant was charged. The defense only prevents the defendant from being convicted of the more serious crime with which the defendant was charged. The defendant may still be convicted of the lesser offense.

The defense of mistake of fact is not a true defense. A defendant does not deny the commission of an offense. The defendant only denies the commission of the offense with which the defendant is charged. However, when the defendant raises the defense, it may eliminate the defendant's criminal liability for an offense because it raises a reasonable doubt regarding the prosecution's proof of an essential element of the offense.

By asserting the defense of mistake of fact, a defendant is generally deemed to have waived his or her right to be charged with the offense that the defendant believed that he or she was committing. In most cases, however, the defendant agrees in writing to waive his or her right to be indicted for the less serious offense after he or she has asserted the defense.

A defendant who claims the defense of mistake of fact is entitled to a jury instruction on the defense. If the jury believes the defendant's evidence, the jury may only convict the defendant of the offense that the defendant admitted. If the jury does not believe the defendant's evidence, the jury may convict the defendant of the offense with which he or she was charged.