1. a claim that the defendant was not in a position to commit the crime charged 2, Diminished capacity test Case-in-chief defense Alter-ego theory M'Naghten test Affirmative defense Mistake of law Mistake of fact Irresistible impulse test Defense of others Alibi Duress

challenges the prosecution's version of the facts but does not introduce an independent legal claim into the case

3. Diminished capacity test Case-in-chief defense Alter-ego theory M'Naghten test Affirmative defense Mistake of law Mistake of fact Irresistible impulse test Defense of others Alibi Duress

the defendant admits committing the acts charged but seeks to justify or excuse the defendant's conduct by establishing additional facts 4. Diminished capacity test Case-in-chief defense Alter-ego theory M'Naghten test Affirmative defense Mistake of law Mistake of fact Irresistible impulse test Defense of others Alibi Duress

an unlawful threat of imminent death or serious bodily injury, which induces a person to commit a crime; may be used as a defense except in the case of murder 5. Diminished capacity test Case-in-chief defense Alter-ego theory M'Naghten test Affirmative defense Mistake of law Mistake of fact Irresistible impulse test Defense of others Alibi Duress

a lack of knowledge of a particular piece of information may be a defense if it negates a material element of the offense