1. Criminal Defenses

2. Criminal defenses
For conviction, prosecutor must establish defendant committed act beyond a reasonable doubt
Defendant not required to present a defense
Instead, can simply force gov’t to prove its case
However, some defenses are available to defendants…

3. No crime has been committed
Defendant may present evidence that…
No criminal act was committed
No criminal intent was involved
Ex: Defendant may admit to carrying a gun, BUT had a valid license
Ex: Defendant may claim to having MISTAKENLY taken another’s coat

4. Defendant did not commit the crime
Often, no doubt exists that a crime has been committed
Question is: WHO committed it?
Defendant might present evidence of a mistake in identity or offer an alibi
Evidence defendant was somewhere else at time of crime
DNA evidence has made it possible to connect offender conclusively to crime

5. Excusable or justifiable act
Self-defense, defense of property, defense of others
Law recognizes right to use reasonable force in self- defense
Cannot use more force than appears necessary
Deadly force can usually be used only by person who reasonably believes life is in danger

6. Excusable or justifiable act
Some states have passed Stand Your Ground laws giving people right to use deadly force to defend property against unwarranted intrusion
Police can only use deadly force in self-defense when suspect poses significant threat of death or bodily harm

7. Defendant Committed the Act, But is not criminally responsible

8. Infancy
Children under 7 usually considered legally incapable of committing crime
Ages 7-14 considered legally incapable of committing crime, but presumption could be proven wrong
Children under certain age have defense of infancy
Some states (1) do not have infancy defense or (2) allow prosecutors to decide whether to try defendant as adult

9. Intoxication
Defendants claim intoxication when, at time of crime, they were so drunk or high that they did not know what they were doing
In general, voluntary intoxication not a valid defense
However, it may sometimes be valid if the crime requires proof of a specific mental state
Ex: Defendant charged with assault with intent to kill, but claims to be so drunk, she could not have formed intent

10. Insanity
People who have a mental disease or disorder should not be convicted if they do not know what they are doing or do not know right from wrong
About half of U.S. states & federal gov’t use this standard
During proceedings, mental state can be issue in determining if defendant…
Is competent enough to stand trial
Was sane at time of act
Is sane after the trial

11. Insanity In most states, 3 verdicts exist: Guilty Not guilty
Not guilt by reason of insanity
Last verdict requires automatic commitment to mental institution
Usually requires psychiatrist to testify
In recent years, some states developed new verdict: “guilty, but mentally ill”
1/3 of states have this verdict
Only ~1% of criminal cases use this defense, seldom successful

12. Duress
Persons acts under duress when he/she does something as a result of coercion or threat to personal safety
Individual lacks ability to exercise free will
Ex: Someone points gun at your heads, demand that you steal money or be killed.
Duress would be good defense if charged with theft
Duress is not a defense to homicide

13. Necessity
Applies when defendant is compelled to react to situation that is unavoidable in order to protect life
Ex: If lifeboat is sinking & you throat cargo overboard to make boat lighter
Necessity a good defense to charge of destruction of property
Necessity not a defense to homicide