•The
defendant is not required to present a
defense, but can simply force the government
to prove their case.
•For a conviction to occur, the prosecutor must
establish that a defendant committed a crime
beyond a reasonable doubt.
•Possible defenses:


Defendant presents evidence that no crime
has been committed
Example: no carnal knowledge because the
woman was of age when she consented to
sex
no criminal intent was involved
Example: a woman picks up a handbag from
the table that looks exactly like hers without
knowledge that it wasn’t hers
 Mistaken
identity
 Defendant has an alibi
 DNA evidence

Self-defense/ defense of others- reasonable
force was used against an unlawful attack
-can not use more force than appears to be
necessary to defend self or others
-if after stocking an attacker, the defender
continues to use force the roles reverse and
the defender can no longer claim self
defense
-deadly force can only be used if the
defender believes that there is an imminent
danger of death or serious bodily harm

-in defense of other can be used if the other
can claim self-defense
Defense of property
-only non deadly force may be used
-Make my day laws enacted by some states
allows persons the right to use deadly force
to defend their property against unwarranted
intrusion
Lack of criminal responsibility even
though they acknowledge that he or
she committed the act

Infancy
-children of a young age, 7 in most states,
are legally incapable of committing a crime
-children between the ages of 7 and 14 are
generally presumed incapable of committing
a crime, but could be shown to be a wrong
presumption
-some states do not try children, simply
turn them over to the juvenile courts
-some states allow prosecutors to decide
whether or not to try a child as an adult


So drunk on alcohol or high on drugs that
they did not know what they were doing
Typically, voluntary intoxication is not a
defense to a crime unless the crime requires
proof of a mental state



Developed from the Greeks, Romans, and
English courts
Modern standard grew from an attempted
murder case of a British Prime Minister in
1843
-people who have a mental disease or
disorder should not be convicted if they do
not know what they or doing or the difference
between right and wrong
Used by about 50% of states and the federal
government




Other 50% must acquit if they lack substantial
capacity to appreciate the nature of the act or
to conform their conduct to the requirements
of the law
Mental state can be an issue in determining
whether
1. defendant is competent to stand trial
2. the defendant was sane at the time of the
crime, and
3. the defendant is sane at trial
Insanity defense only applies is insane at time
of crime
Insanity only at time of trial only delays trial
-does not affect criminal liability
Insanity defense usually means the person
will be automatically committed to a mental
institution
 About 1/3 of states have a fourth verdict:
guilty, not guilty, guilty by reason of insanity,
guilty but mentally ill
-persons found guilty by the 4th verdict
would send them to a hospital and later
transferred to a prison when they are found
sane
-abolished by the states of Montana, Idaho,
and Utah
-used in about 1% of criminal cases and is
seldom successful





Defendant admits to committing the crime
but claims that law enforcement persuaded
them to do so
Does not apply to the officer only providing
the opportunity to commit the crime
Defense must show that the defendant would
not have committed the crime but for the
inducement of the officer
Difficult to prove



When the defendant does something as a
result of coercion or threat of immediate
danger
Person cannot exercise free will
Not a defense to homicide


Compelled to react to a situation that is
unavoidable in order to protect life
Not a defense to homicide