There are several defenses that negate criminal capacity. These include:

· Insanity

· Intoxication

· Infancy

· Diminished capacity – only in some jurisdictions.

The defense of insanity can be applied to all crimes and is evaluated by the M’Naghten test.

Intoxication can be either voluntary or involuntary. Voluntary intoxication is a defense to a specific intent crime if the intoxication keeps the defendant from forming the required intent. Involuntary intoxication is a defense to all crimes.

Defendants under 14 years of age under common law, and defendants under age 13 or 14 can raise the defense of infancy. Under common law, anyone under 7 years old has an absolute defense to all crime. If the child is under 14 years old, there is a rebuttable presumption to the offense. Under Modern Statutes, a child who is under 14 years old has a defense to adult crimes, but could be delinquent.

Diminished capacity crimes are usually limited to specific intent crimes.