As part of a criminal defense strategy, a defendant may seek to present evidence which includes justifications, excuses, or mitigating factors concerning criminal acts. If successfully established, three defenses may work to either negate criminal liability or decrease the sentencing of a criminal case.


If a defendant can present a successful justification for his actions, he will be fully cleared from criminal liability. In other words, society accepts that his otherwise criminal act as appropriate under the circumstances. Here are several examples:

  • Self-defense and defense of others, as well as defense of property (providing deadly force is not used).
  • Crime prevention (with use of deadly force usually restricted to dangerous felonies).
  • Necessity – where a person causes harm in order to prevent an even greater harm to society (i.e., breaking water pipe to stop fire threatening to the neighborhood, etc).
  • Reasonable mistake of fact.


Unlike justifications, excuses don’t negate a defendant's wrongful act. However, while the defendant's act is considered criminal, the defendant lacks moral guilt and is therefore excused from punishment. Here are some examples of excuse defenses:

  • Duress or coercion – where the defendant commits the criminal act under threat of immediate bodily harm or death. Duress can never be used to justify homicide.
  • Involuntary Intoxication – if the defendant became intoxicated through no fault of his own (i.e., somebody mixed narcotic into his drink), he is not liable for getting intoxicated and for committing crimes in such a state.
  • Legal Insanity – where the defendant's mental defect prevented him from understanding or controlling his actions.
  • Entrapment – if the criminal act originated with an inducement from law enforcement, the defendant would be acquitted.
  • Infancy – today, many criminal statutes set a certain minimal age for criminal liability (usually 13 or 14).
  • Reasonable mistake of fact.

Mitigating Factors

If mitigating factors are present, the defendant will not be acquitted, but he may be charged with a lesser offense. Mitigating factors usually focus on the defendant's mental state, eliminating the defendant's specific intent. Examples include:

  • Voluntary intoxication – this may negate some specific intent or premeditation to commit a crime.
  • Diminished capacity – when full insanity cannot be established, some jurisdictions allow the use of some mental defects to negate the defendant’s intent to commit a crime.
  • Mistake, reasonable or unreasonable, can serve as mitigating factor by negating specific the intent required for some crimes.
  • Heat of passion – where the defendant commits a crime while provoked. The defendant's criminal charge may be mitigated from murder to voluntary manslaughter.
  • Imperfect self-defense – if the defendant applies deadly force, making an honest but unreasonable mistake that such force is necessary for self-defense, he may be guilt of voluntary manslaughter instead of murder.

How Can an Attorney Help?

A qualified criminal defense attorney may clarify your specific situation to develop a successful criminal defense strategy. An attorney may examine and recommend various excuses, justifications, and mitigating factors that may decrease criminal liability.