There are four types of recognized criminal law defenses:
Alibi. A Latin word that means “in another place.” The defendant could not have committed the crime because he or she was elsewhere during the crime commission.
Justification. The defendant admits to the act but claims that it was necessary to avoid a greater evil. Examples include self-defense, defense of others, and defense of property, consent, necessity, and resisting unlawful arrest.
Excuse. Some personal condition or circumstance at the time of the act was such that the actor should not be held accountable under the criminal law. Examples include duress, age, mistake, provocation, unconsciousness, insanity, involuntary drunkenness, diminished capacity, and mental incompetence.
Procedural Defense. In some significant ways, the defendant was discriminated against in the justice process. Or some critical aspects of the official procedure were not correctly followed in the investigation or prosecution of the crime charged. Examples include entrapment, double jeopardy, collateral estoppel, prosecutorial misconduct, denial of a speedy trial, police fraud, and selective prosecution.