What is a "defense of necessity" in criminal law?

The "defense of necessity" in criminal law refers to a legal argument indicating that an individual committed an act considered criminal, but did so to prevent a greater harm from occurring. This defense acknowledges that the act itself is illegal but asserts that it was necessary under the circumstances to avert a more significant danger or harm.

For example, if a person breaks into a cabin during a snowstorm to avoid freezing to death, they may claim necessity, arguing that their illegal entry was warranted to save their life. The key element of this defense is the balancing of harms: the harm avoided must outweigh the harm caused by the illegal act.

This defense is distinct from a justification for reckless behavior, which would not align with the legal reasoning behind necessity. It also differs from simply being based on circumstantial evidence, as necessity requires a clear demonstration of the urgency and legitimacy of the threat faced. Lastly, it is not a tactic to confuse the jury; instead, it seeks to rationalize the defendant's actions in light of the circumstances that compelled those actions.