1. Defences to crimes Defences
First thing to say is that there are huge differences between states
Model Penal Code – model set of criminal laws, but while lots of states have adopted some of its provisions, very few states have used all of it
Means that on matter looking at – remember there can be big difference between jurisdictions – between states (and federal law)

2. Defences Justifications and excuses defences in criminal law
admit that the defendant committed an act proscribed by law
lead to acquittal
Both defences in criminal law
Both admit that the defendant committed an act proscribed by law
Both types if successful lead to acquittal
If a defence, like the ones we will look at today succeeds > then the defendant is found not guilty / acquitted
Defences are not mitigating factors Mitigating factors > lower sentence
Defences lead to acquittal

3. Justifications
The principle behind these defences is that the D should not be convicted of a crime, as his acts were justified

4. 1. The defence of necessity
D had a reasonable belief in an actual and imminent threat
There was no other reasonable alternative response
D’s response prevented a greater harm (= he chose the lesser of two evils)
D must not have contributed to creating the threat
D ceased the criminal conduct as soon as possible
The defense of necessity may apply when an individual commits a criminal act during an emergency situation in order to prevent a greater harm from happening.
For example, breaking into a house is usually illegal. But if it is done in order to save occupants from a fire, then it is justified.
It’s use is limited by strict conditions. (From Florida case, Bozeman v. State 1998)
1) The defendant must reasonably have believed that there was an actual and specific threat that required immediate action
Threat - danger
Imminent – the harm is about to happen
2) that there existed no other reasonable alternative response to avoid the threatened harm except the criminal conduct
3) D’s response prevented a greater harm (= he chose the lesser of two evils) that the harm D sought to be avoid must be worse than the criminal conduct perpetrated to avoid it
4) D must not have contributed to the threat > Bozeman, made more specific > D did not intentionally or recklessly place himself in a situation in which it would be probable that he would be forced to choose the criminal conduct
5) D ceased the criminal conduct as soon as the necessity or apparent necessity for it ended

5. 2. Self-defense and defense of others
If someone physically harms somebody else, they may find themselves charged with a crime, such as assault, or murder.
However, it is an accepted legal principle that someone generally has the right to protect themselves from an aggressor.
Consequently, SD is a legal defence to crimes against the person -.

6. Justifications: self-defense
A person can use physical force to defend himself or someone else if
he reasonably believes that there is an imminent threat of immediate injury
his response is proportional to the threat
Duty to retreat
in some states, using lethal force in self-defence is only justified if D has first attempted to flee
stand your ground laws remove this duty
the castle doctrine removes this duty within one’s home
A person can use physical force to defend himself or someone else if
he reasonably believes that there is an imminent threat of immediate injury
his response is proportional to the threat D's response must be proportional to the threat – in some jurisdictions (states) there must be a threat of death to justify the use of deadly force, in others a threat of serious injury suffices
Duty to retreat
in some states, using lethal force in self-defence is only justified if D has first attempted to flee > must try to run away or otherwise avoid confrontation
Other states explicitly remove this duty, using stand your ground laws – vary between states, but in some states apply in any public place where the D legally had the right to be, others limited to cars and homes
Most states have some variation of The castle doctrine: means there is no duty to retreat if the D is in his own home

7. Excuses
D committed a crime, but he is not culpable, because the act was not entirely voluntary

8. 1. Involuntary intoxication
Involuntary consumption of drugs / alcohol
Specific intent crimes:
aggravated battery “intentional and harmful physical contact with another with the intent to maim or disfigure.”
intoxication must prevent the defendant from forming the required intent
General intent crimes:
intoxication prevented the defendant from understanding the nature of his or her actions or differentiating between right and wrong.
Involuntary intoxication occurs when someone is tricked into consuming a substance like drugs or alcohol, or when someone is forced to do so. For instance, a woman who has a date rape drug placed in her drink without her knowledge is involuntarily intoxicated. Involuntary intoxication may also occur as a result of an allergy to, or the unintended effects of, a legal prescription medication.
The operation of this defence depends on type of offence;
specific intent crime, means that the prosecutor must prove that the defendnat had a specific intention, >, aggravated battery “intentional and harmful physical contact with another with the intent to maim or disfigure.”> involuntary intoxication can be a defense to criminal charges if it prevents the defendant from forming the intent that is required..
General intent crimes: don’t require a specific intent > action must be intentional or reckless, buit doesn’t require that the defendnat was trying tio achieve a specific result.
battery as “intentional and harmful physical contact with another person.”
Involuntary intoxication can also be a defence to a general intent crime if the defendant can establish that the involuntary intoxication prevented the defendant from understanding the nature of his or her actions or differentiating between right and wrong.
Unlike involuntary intoxication, voluntary intoxication is never a defense to a general intent crime. However, voluntary intoxication may be used as a defense to specific intent crimes if, as with involuntary intoxication, it prevents the defendant from forming the criminal intent necessary to commit the crime. Thus, a defendant could argue voluntary intoxication as a defense to burglary because he was so intoxicated that he was unable to form an “intent to commit a crime therein.” However, in most states, the crime of voluntary intoxication is an affirmative defense, which means that the burden is on the defendant to prove that he or she lacked the necessary intent.
In some cases, the defense of voluntary intoxication does not completely absolve the defendant of liability but instead reduces the overall culpability for the crime. Thus, the defendant might find charges reduced to a lesser crime if he or she successfully proves that intoxication limited his or her intent or comprehension of the crime.

9. 2. Duress
Requires:
an actual threat of immediate or imminent death or serious bodily harm
which creates a reasonable fear in the defendant, and
which leaves D with no reasonable means to escape the threat except by committing the crime.
The defense of duress is available to criminal defendants who were forced to commit a crime under threat of violence or because of the actual use of violence. In these circumstances, the courts have determined that a defendant was deprived of the free will to make a decision to commit the crime and thus should not be held legally responsible for it.
Requires:
an actual threat of immediate or imminent death or serious bodily harm to D or someone he has a significant relationship with
which creates a reasonable fear in the defendant, and > means a reasonable person in the same situation would have taken the threats seriously, well-grounded fear that the threats would be carried out
which leaves D with no reasonable means to escape the threat except by committing the crime.
Most states will not accept duress as a defence to murder

10. 3. The insanity defence
If D can prove that he was insane when he committed a crime, he will
be found “not guilty by reason of insanity”
be committed to a secure mental institution

11. The insanity defence In many states the D must prove
that he suffered from a mental disorder
which meant that he did not know what he was doing, or did not know that it was wrong
(or he could not stop himself from committing the crime)
In many states the D must prove
that he suffered from a mental disorder
which meant that he did not know what he was doing, or did not know that it was wrong
Comes from an English case 1843 M’Naghten rules
In some states – irresistible impulse component : (or he could not stop himself from committing the crime)
Federal law – requires a serious mental disease or defect
4 states have abolished the insanity defence
In a majority of states, the burden is placed on the defendant, who must prove insanity by a preponderance of the evidence.(more than 50%)
In federal court, and in Arizona, the burden is placed on the defendant, who must prove insanity by clear and convincing evidence
In a minority of states, the burden is placed on the prosecution, who must prove sanity beyond a reasonable doubt.