I. BASIC DEFINITION - Act + Mental State + Result = Crime – Defenses
II. ACTUS REUS - a voluntary act, omissions do not usually count.
A. VOLUNTARY ACT
COMMON LAW
Requires a voluntary and a social harm An act
is voluntary if  willed the action or if she was
sufficiently free that she could be blamed for
her conduct. The social harm is the wrong
caused by 's voluntary act.
MPC
No person may be convicted of a crime
in the absence of conduct that includes
of which he is physically capable.
DIFFERENCES
MPC
Same as CL criminal liability imposed
for the omission of an act which  is
physically capable.
DIFFERENCES
None
MPC
Involuntary acts: reflex, convulsion,
movements during sleep, movements
under or the result of hypnosis, and
unconscious movements.
DIFFERENCES
MPC extends CL such that acts
done under hypnosis and in
states of unconsciousness are
"no action."
B. EXCEPTIONS
1. OMISSIONS
COMMON LAW
No crime unless there is a legal duty to act
Types:
Statute
Contract
Special Relationship
Assumption of Care
Peril wrongfully created for another
NOTES
Not obtaining reasonably
available help can make 
liable, no matter what ’s
physical capabilities.
2. INVOLUNTARY ACT
COMMON LAW
Can negate the action or serve as an
affirmative defense. Done in a state of
unconsciousness
III. MENS REA - A mental state is required for most crimes.
Strict liability and public welfare offences are the exception. To
prove an offense, the prosecution must prove mens rea as to every element of the offense
A. TYPES
COMMON LAW
Intentionally (willfully) – to consciously
cause the result or when one is virtually
certain that the object will occur as a result of
's conduct.
Recklessness – A heightened criminal
negligence or conscious disregard of a
substantial and unjustifiable risk.
Negligence – Objective fault  should have
been aware that his conduct created a
substantial and unjustifiable risk that the
social harm would result.
Maliciously - when one intentionally or
grossly reckless causes the social harm
prohibited by the statute.
MPC
Purpose - conscious object with
conduct & results. Must be aware of the
existence or believe or hope that such
circumstances do exist
Knowledge – Conscience awareness
that results are practically certain to
occur
Recklessness - Conscious disregard of
a substantial and unjustifiable risk.
Negligence – Should have been aware
of a substantial and unjustifiable risk.
Rule of thumb
Purpose = desire for a certain outcome
Knowledge = indifference to a certain
-1-
DIFFERENCES
MPC splits intentionally into
purpose and knowledge
MPC clear distinction between
negligence and recklessness not on the degree of risk
involved but on D's knowledge
of the risk.
MPC provides that when it is
not clear which element a mens
rea applies to, apply it to all
elements of the offense
Where the statute is silent on
Mens Rea, recklessness is
required.
outcome
Willful Blindness
MPC - if one deliberately
avoids knowledge because of
the belief that knowing would
be bad, then  satisfies mens
rea of knowledge. Requires
high probability
CL - Only have to be aware of
probable existence of element
MPC
For a crime requiring a mens rea of:
Purpose -  must be aware of the
existence of such circumstances
(attendant), or believes or is aware they
exist
DIFFERENCES
B. ATTENDANT CIRCUMSTANCES
COMMON LAW
?
Knowledge - Aware that his conduct is
of that nature or that such
circumstances exist: only requires high
probability of existence.
Reckless: Conscience disregard of
substantial and unjustified risk
Negligence - Should be aware of
substantial or unjustified risk
C. SPECIFIC INTENT/GENERAL INTENT
COMMON LAW
Applies to mens rea. Defined by the crime
MPC
MPC does not distinguish between
general and specific intent.
DIFFERENCES
This is exclusively a CL issue.
General Intent – volitional doing of a
prohibited act. Only require intent to commit
the act constituting the crime. Can infer all
mens rea from observing the conduct.
General intent –  desired to
commit an actus reus;
Special intent –  desired to
bring about something further
Specific Intent – intent to do some further act
or cause some additional consequence beyond
that which must have been committed or
cause in order to complete the crime. Acts in
addition to general intent. Proof of specific
intent is required , but it may be
circumstantial.
An alternative definition
Specific - intent to do conduct
and a further intent.
General - intent to do the
conduct.
To negate specific intent, a mistake must be
honest.
To negate a general intent, the mistake must
be honest and reasonable.
D. STRICT LIABILITY - Where there is no mental state required for an offense
COMMON LAW
MPC
-2-
DIFFERENCES
Public welfare and traditional crimes. Created
by statute
Under MPC, SL crimes are generally
restricted to violations and are
punishable by fines, not incarceration public welfare crimes;
MPC is generally the same as
CL.
IV. RESULT
A. CAUSE IN FACT - Causation is only required for result crimes.
COMMON LAW
Conduct satisfies the but-for test. Actual
cause exists when the result that constitutes
the criminal offense would not have occurred
when it did but for 's voluntary act (or
omission)
MPC
MPC only requires actual causation and
uses the same but-for test as CL.
Cause in fact
DIFFERENCES
MPC only requires actual
causation.
MPC
MPC handles proximate causation
within the mens rea as to results.
Whether the result was too distant or
accidental in occurrence to have a just
bearing on 's liability or on the gravity
of the offense.
DIFFERENCES
For MPC, proximate causation
is handled within mens rea.
B. PROXIMATE CAUSE
COMMON LAW
Forseeability Test
To determine proximate cause, one must
determine whether the actor was the direct
cause and whether there were any intervening
actors or intervening causes (coincidences)
that severer the causal chain back to 
No intervening causes unless the cause is
foreseeable or de minimus.
Intervening Acts - Intervening acts can
sufficiently break the chain of causation;
Dependent intervening acts: occur where
the intervening actor acts because of a
condition brought upon by the D’s prior
conduct. However, if the dependant
intervening actor was grossly negligent, this is
sufficient to break the chain of causation.
Voluntary Intervening Act: occur where the
intervening actor acts voluntarily. Intentional
acts always break the chain of causation;
reckless acts are sometimes sufficient
(depending on court).
If the result deviates too far from what
is foreseeable, then one will be
exculpated for purpose and knowledge
crimes. If not, then  will be
convicted even if there is an
intervening actor.
For risky crimes, the result must have
been foreseeable in order to convict
Purp/Know: Causation not
established if result was not
what was intended, unless:
1.  just a different person
(Transferred Intent)
2. Injury less than intended
Reck/Neg: Causation not
established if result not within
risk the actor was or should
have been aware of, unless:
1.  just a different person
(Transferred Intent)
2. Injury less than risked
Exceptions to forseeability:
Take the Victim as you find
him - Condition unforeseeable,
but  still liable
Transferred intent - Result
unforeseeable but  still liable
Voluntary intervening act Result foreseeable but  not
held liable.
C. COMPLICITY
1. ACCOMPLICE - An accomplice is one who intentionally assists another person to engage in conduct that constitutes the
offense
COMMON LAW
Types
MPC
Types
-3-
DIFFERENCES
MPC - no actual assistance for
Principal in the 1st degree – Actually engage
in the act or omission that constitutes the
criminal offence
Principal in the 2nd degree – incites or abets
and is present, either actively or constructively
at the time of the crime
Accessory before the fact – incites or abets
but is not present at the time of the crime.
Accessory after the fact - intentionally assists
the principal after the crime.
Actus reus, mens rea and principal’s
completion of the offense
Actus reus
Abetting or inciting - The  must have
directly of indirectly encouraged of facilitated
the commission of the offence.
Abetting -is any significant assistance in the
commission of an offense
The aid must impact upon the actual
perpetrator
aid does not have to be necessary for the
successful commission of the offense.
perpetrator doesn’t’ have to be aware of the of
the accessory’s assistance.
Inciting – encouragement even if not
accompanied by physical aid.
Perpatrator must be aware of encouragement
Being present at crime with prior agreement to
aid is sufficient encouragement
Principal – Acting with the requisite
mens rea, actually engages in the act or
omission that causes the crime, or acts
through an irresponsible or innocent
agent (Innocent Instrumentality) to
commit the offence
Accomplice – incites or abets with
requisite intent before or during the
commission of the offense. Includes
solicitation and omission when a duty
is present.
mens rea
Purposefully promotes or facilitates in
the commission of a crime.
Must act with culpability sufficient for
the commission of the offense
Note that this is especially significant
in jurisdictions with felony murder
because it makes an accomplice in the
conduct (underlying felony) strictly
liable for the resulting death because he
had the requisite mens rea as to the
result. This is how MPC deals with
accomplice liability in reckless or
negligent contexts.
Mens rea
Mental state required for commission of the
target offense
Intend for action to assist or encourage in the
successful completion of the crime
Substantiality of aid can also
create complicity. Complicity
may also be established if there
is sufficiently substantial
benefit to the knowing
facilitator.
Generally, this second element can be inferred
from the first.
Accomplice is liable for all crimes that are a
reasonably foreseeable result of the
contemplated crime. Some jurisdictions allow
's to be accomplices to reckless or negligent
crimes.
a. DEFENSES
COMMON LAW
Withdrawal
Must take place before the events are
unstoppable
Inciter – communicate an renunciation of the
crime to the perpetrator
accomplice liability is
necessary. Agreement to aid is
enough.
MPC - accomplice can be
convicted even if the
perpetrator has not yet been
prosecuted, has been convicted
of a lesser crime, has been
acquitted, or is feigning.
MPC - does not recognize the
natural and probable
consequences rule for homicide
found in CL. MPC - one who is
legally incapable of committing
an offense may be accountable
for the crime if another person
for whom he is legally
accountable commits it.
MPC - knowing facilitation is
not enough to establish liability.
A victim cannot be an
accomplice.
MPC includes the crime of
attempt to aid and abet.
CL - If the perpetrator is
justified, then there is no
accomplice liability because
there is no crime.
CL- excuses do not transfer
from perpetrator to accomplice
A victim accomplice (underage
girl in statutory rape) cannot be
an accomplice unless there is a
legislative exception.
Knowing or reckless facilitation
is sufficient to establish
complicity in some courts
MPC
Withdrawal
Wholly depriving his prior assistance
of effectiveness,
Provide a timely warning of the plan to
law enforcement
-4-
DIFFERENCES
Abettor – Must render the assistance  gave
ineffective
Make an effort to prevent the
commission of the offence
V. CRIME
A. INCHOATE
1. ATTEMPT - an act done with the intention of committing a crime, that falls short of completing a crime
COMMON LAW
Mens Rea For the Attempt - Specific intent to commit
the acts or cause the resulting target crime.
For the Target crime - Intent necessary for the
target crime (specific or general depending of
the offence) For strict liability must only show
intent to attempt, no target crime mens rea
Reckless crimes – Courts generally do not try
for attempts of reckless crimes.
Negligent crimes - Attempt to commit is
logically impossible
Actus Reus
Tests
Proximity test – conduct must be physically
proximate to the intended crime. Focuses on
what remains to be done.
Indispensable Elements – Control over all
factors in the commission of the crime.
Nothing must be left undone
MPC
Mens Rea For the attempt – Purposely or
knowingly engages in conduct which
would constitute the crime if the
attendant circumstances were as 
believes them to be.
For the Target crime –  acts with the
kind of culpability otherwise required
for the commission of the offense.
However, here too, the mens rea for
attempt is often higher than the one
required for the target offense.
Generally, the required mens rea is
purpose.
DIFFERENCES
Under MPC,  may still be held
for the attempt even if the target
offense is neither committed
nor attempted by  or anyone
else.
CL - no definitive Actus Reus
test
MPC - does not use general vs.
specific intent language.
Most states no attempt for
Felony Murder
Actus Reus
 must perform a substantial step
toward committing the crime.
’s conduct must be corroborative of
's purpose.
.Attempt is a felony.
Probable desistance - Likelihood that  would
cease efforts to commit the crime given the
conduct  has already committed.
Unequivocal (res ipsa loquitur) – An act
amounts to attempt only if it firmly shows the
’s intent to commit the crime. The act
“speaks for itself”
Last Proximate Act - test has been universally
rejected, is traditional common law
Attempt is a misdemeanor.
a. DEFENSES
COMMON LAW
mistake of fact
no mistake of law
legal impossibility
no factual impossibility
MPC
No mistake of fact
No mistake of law
Legal impossibility.
No factual impossibility
No hybrid impossibility
-5-
DIFFERENCES
MPC – Only “true” legal
impossibility is a defense
’s conduct is an attempt if it
was only prevented by 's
mistake of fact.
Abandonment
Traditionally never a se. Abandonment is a
se when it is complete and voluntary. Once
's actions have passed the point of being an
attempt is not generally a se.
Abandonment:
Is a se only if:
It is fully voluntary and not made
because of the difficulty of completing
the crime or because of an increased
risk of apprehension
It is a complete abandonment of the
plan made under circumstances
manifesting a renunciation of criminal
purpose, not just a postponement
2. CONSPIRACY
COMMON LAW
Actus Reus
MPC
Actus Reus
agreement to commit a criminal act or series
of acts, or to accomplish a legal act by
unlawful means.
Object of Agreement - need only be unlawful /
wrongful.
Nature of the Agreement - need not be written
or even express. Can be implied from the
action of the actors
Act Doctrine - no further act is necessary in
most jurisdictions.
Merger - does not merge into an attempt or the
completed offense.
Agreement to commit a crime; attempt
to commit a crime; solicit another to
commit an offense; aid another in
planning or commission of an offense.
Object of Agreement - must be a
criminal act.
Nature of Agreement - ?
Act Doctrine - No overt act is required
for serious (1st or 2nd degree) felonies,
but required for all other offences.
Merger - merges unless there are
further conspiratorial crimes to be
carried out.
Mens Rea
Mens Rea
CL lets  off if state cannot
prove that there was another
person with the requisite mens
rea.
Specific intent crime with 2 parts:
intent to agree
intent to carry out the object crime.
purpose to promote or facilitate the
object crime.
Overt act requirements differ.
MPCe merges and CL does not.
Mere knowledge is not usually enough,
but can be when combined with a stake
in the success of the object crime.
MPC has heavier punishments.
Some courts allow conviction if the second
mens rea (as to object crime) is merely
knowledge.
Attendant Circumstances - court has held that
mens rea here is the same as for the
substantive crime, even if it is strict liability.
Attendant Circumstances - Code is
silent here, expressly leaving this to the
court to decide.
Number of Parties Needed - two or more with
the requisite mens rea (multilateral theory).
Number of Parties Needed - one with
the requisite mens rea (unilateral
theory).
Punishment - some jurisdictions treat all
conspiracies as misdemeanors, usually graded
in relation to the target offense.
Punishment - punishment is the same
for conspiracy as for the object crime in
all cases but 1st degree felonies.
Pinkerton Test - all members of a conspiracy
can be held as accomplices of the crime and of
any foreseeable result of it. Liability holds
even if the co-conspirator did not assist the
perpetrator.
Pinkerton Doctrine is rejected - if the
conspiracy goes beyond the intended
purpose, one is not guilty of any
foreseeable crime unless he can be said
to have aided and abetted in its
-6-
DIFFERENCES
MPC - knowledge is not
enough. CL - knowledge may
be enough.
MPC does not speak on
attendant circumstances.
Object of agreement must be
criminal under MPC vs.
unlawful / wrongful in CL
MPC is unilateral.
MPC rejects the Pinkerton
Doctrine.
CL Attendant Circumstances is
counter-intuitive because how
can you agree to do something
of which you are not aware.
CL - In jurisdictions that do not
accept Pinkerton, you can be a
conspirator and not an
accomplice.
Hearsay evidence may be
brought in to prove the
conspiracy, but not the
substantive offense.
commission.
a. DEFENSES
COMMON LAW
No factual Impossibility
No legal impossibility
MPC
No factual impossibility
No legal impossibility
Abandonment
Abandonment
once the offense is completed (once there is
agreement) abandonment is not a defense.
Can relieve liability for future crime of former
conspirators.
if the conspirator renounces his
criminal purpose and thwarts the
success of the conspiracy under
circumstances demonstrating a
complete an voluntary renunciation of
criminal intent.
DIFFERENCES
B. HOMICIDE
1. MURDER - unlawful killing of a human being
COMMON LAW
Homicide with malice aforethought.
Malice Aforethought has four possible states
of mind
intention to kill another human - One may,
but need not, infer the intent to kill from the
use of a deadly weapon
MPC
A killing committed purposely or
knowingly, or gross recklessness.
Premeditation and deliberation are not
required.
Gross recklessness – reckless under
circumstances manifesting extreme
indifference to human life.
intention to inflict serious bodily harm (great
bodily injury)
DIFFERENCES
MPC includes GBH under
recklessness.
MPC's mens rea is equivalent to
CL's intent.
When MPC uses recklessness
as the mens rea, it is similar to
CL's malignant heart killings.
Statutes have been enacted
whick give degrees of to CL
murder
Gross recklessness (malignant heart)- Acts in
the face of an unusually high risk that conduct
will cause death of serious bodily harm. Under
certain exceptional circumstances.
first degree includes certain
enumerated types of homicide
(lying in wait; by poison, etc.);
or a willful, deliberate, and
premeditated (WDP) killing; or
felony murder (enumerated
felonies include arson, rape,
robbery, or burglary).
Felony murder - during the commission or
attempted commission of a felony in which
death results.
All other forms are 2nd degree
murder. "malignant heart" is
usually 2nd degree
a. PROVOCATION - mitigates murder to voluntary manslaughter
COMMON LAW
MPC
Must committed in sudden heat of passion
Extreme Mental or Emotional
under adequate provocation
Disturbance - Homicide committed
under the influence of extreme mental
Heat of passion
or emotional disturbance for which
Adequate provocation:
Aggravated assault or battery
there is reasonable explanation or
Mutual combat
excuse.
Serious crime against close relative
MPC equivalent of provocation
-7-
DIFFERENCES
MPC requires that  be aware
of the risk being taken
(recklessness). MPC’s use of
EMED is a broader form of the
CL provocation defense.
Illegal arrest
Observation of infidelity
No cooling off period
Causal link between provocation, passion
and homicide
EMED v Heat of Passion
(HoP)
EMED applies to all types of
homicide vs. HoP se only
applies to intentional homicides
EMED words alone may be
adequate vs. HoP where they
are not
EMED has no cooling time
requirement and HoP does.
b. FELONY MURDER
COMMON LAW
One is guilty if she kills another person, even
accidentally, during the commission or
attempted commission of any felony.
Inherently dangerous test – The lower bound
for acceptable felonies. The felony must be
inherently dangerous.
Merger Rule – Upper bound for acceptable
felonies. Felony must be independent from
the murder. This excludes felonies arising
during the commission of a murder.
The causation limitation requires that the
killing be in furtherance of the felony. The
mere fact that a death occurs during the
commission of a felony will not necessarily
subject the felon to felony M.
MPC
Does not distinguish felony murder, but
MPC raises a presumption of
“recklessness and indifference to
human life” if the  during the
commission or attempt of certain
felonies. However, this is not absolute,
the prosecution must still prove it. The
jury is simply permitted to infer
extreme indifference to human life
from the commission of the felony. 
may present evidence that the felony
was committed the in a manner that
does not manifest extreme indifference
to human life. It is up to the jury to
decide. Therefore, gross recklessness
during a felony can be a predicate for
felony M.
DIFFERENCES
Code does not have an express
felony M rule.
MPC
Reckless - unlike reckless M, here the
conduct, although reckless, does not
manifest an extreme indifference to the
value of human life
DIFFERENCES
If the felony is one of the
enumerated felonies (arson,
burglary, robbery, or rape), then
this M is 1st degree. If not, then
it is 2nd degree.
The central issue is the foreseeable risk of
death. In most jurisdictions, no felony M if
the person who commits the homicide is a
non-felon who is resisting the felony.
A few states apply a proximate causation test
which holds a felon responsible for the killing
by a non-felon if the felon proximately caused
the death / set in motion the events that lead to
the death.
Suicide Exception - if the co-felon shoots
himself, it is not homicide at all, but a suicide
2. MANSLAUGHTER
COMMON LAW
Voluntary MS – homicide without malice
aforethought
"Heat of passion" - Intentional killing
committed in response to legally adequate
provocation
Extreme Mental or Emotional
-8-
Disturbance (EMED)
Imperfect justification – A killing that is the
result of an act, lawful in itself, but done in an
unlawful manner.
Involuntary MS – unintended killing
Criminal Negligence – Killing resulting from
gross negligence. (This would include MPC
recklessness as well)
Unlawful Act “Misdemeanor manslaughter” an unintentional killing that occurs during the
commission of an unlawful act. Includes
malum in se (wrong in itself) felonies and
misdemeanors.
3. NEGLIGENT HOMICIDE
COMMON LAW
None
MPC
A criminally negligent killing
DIFFERENCES
Equivalent to involuntary MS
under the Common Law
VI. DEFENSES
A. JUSTIFICATION - conduct that is otherwise criminal, but that here is either "right" or "not wrong" under the circumstances.
1. SELF DEFENSE
COMMON LAW
 if not the aggressor is justified in using
force if
MPC
 if not the aggressor is justified in
using (deadly) force if
 reasonably believes it is necessary to defend
’s person
 must be threatened with a physical harm
 reasonably believed the threatened harm is
unlawful
The force used must be proportional.
 honestly believes such force is
immediately necessary to protect ’s
person
harm is unlawful
Deadly force must additionally show
reasonable belief  is imminently facing
deadly force.
 had no opportunity to retreat (Old common
law standard)
 may always use non-deadly force to protect
oneself against an unlawful aggressor.
When  is the aggressor, he loses his right to
use force.  may purge himself of his status as
the aggressor and regain his right to selfdefense by removing himself from the fray
and successfully communicating that fact.
If , as the aggressor uses non-deadly force,
and victim responds with deadly force,  may
immediately regain his right to self-defense.
Deadly force is justified if one faces a
threat of death, GBH, forcible rape, or
kidnapping. A threat without that
purpose is not deadly force, even if a
weapon backs up the threat.
If  know/realizes he can be
completely safe by retreating  must
if  unlawfully starts a non-lethal
conflict, he does not lose his privilege
of self-defense if V escalates it into a
lethal assault.
Retreat is required within one's home or
office if the actor was the initial
aggressor and he wishes to regain his
right to self-defense or even if he was
not the aggressor
 no duty to retreat from home, even
from a co-dweller.
-9-
DIFFERENCES
MPC looks at the 's subjective
belief, the belief need not be
reasonable.
If 's belief was negligently or
recklessly formed, one can be
liable for reckless or negligent
use of deadly force
MPC replaces imminence with
the phrase "immediately
necessary" so that one may use
force sooner under than CL.
MPC - deadly force is more
broad than CL one who acts
with the purpose causing death
or GBH qualifies
In CL force not likely to cause
death or GBH is not deadly
force even if it was the 's
purpose to kill.
MPC does not include the nondeadly aggressor
 does not have to retreat within 's own
dwelling even if one could do so in complete
safety.
2. NECESSITY
COMMON LAW
 is justified if he reasonably believes that he
is avoiding the greater evil.
Balance of evils must be positive.
There must not be an alternative.
The harm must be imminent.
 may not have created the necessity.
 can never take another's life out of
necessity.
se only applies when a natural force created
the necessity.
When the balance of evils is negative,  may
be held strictly liable.
MPC
 is not justified unless  not only
reasonably believe that  is avoiding
the greater harm, but  is actually
avoiding the greater harm.
Balance of evils must be positive.
There is no immediacy requirement a
 may not have intentionally caused the
necessity.
 may take a life if the balance of evils
is positive. se may apply in homicide
cases
This se applies but not limited to
emergencies created by natural forces,
nor is limited to physical harm to
persons or property.
If 's belief is mistaken, can be held for
crime requiring either negligence or
recklessness.
If  negligently or recklessly caused
the necessity, he may be held for
crimes of negligence and recklessness.
DIFFERENCES
MPC requires that 's
reasonable belief actually be
true.
MPC does not have an
immediacy requirement.
MPC if  caused it accidentally,
he can still claim necessity
though if he recklessly or
negligently created the
necessity, he may be held for
crimes of recklessness and
negligence.
MPC allows se in cases where
a natural force did not create the
necessity.
.
B. EXCUSE - wrongful conduct, but under the circumstances, D is not morally culpable or blameworthy
1. DURESS
COMMON LAW
 may be excused if
 was threatened with death or GBH (or if a
3rd party is so threatened) by another human
 reasonably believes that the threat is
genuine
felt that the threat was "present, imminent,
and impending" at the time of the act
 felt that the only way to avoid the harm was
to give in to the threat
 was not at fault in exposing himself to the
threat.
Duress is not a defense to an intentional
killing. Some states recognize an imperfect
defense whereby murder is reduced to
manslaughter.
MPC
Duress is an affirmative defense to
unlawful conduct by  if
was compelled to commit the offense
by the use or threatened use of force by
the coercer upon her or another
A person of reasonable firmness in 's
situation would (also) have been unable
to resist the coercion.
se is not available if  recklessly
placed herself in the position where she
would likely be subject to coercion.
If  negligently put herself into such a
position, the se is available to her for
all cases except those in which
negligence suffices to establish
culpability.
DIFFERENCES
MPC abandons the CL
requirements of deadly force
and immanency in favor of
excusing  whenever a person
of reasonable firmness would
also have yielded to coercion;
MPC se is one of general
applicability may be used in
murder cases
MPC does not require that an
imperiled party be s relative.
MPC similar to CL in that se
is limited to threats or use of
unlawful force and does not
apply to coercion by natural
sources.
MPC does not recognize se
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when any interest other than
bodily integrity is threatened.
2. INSANITY
COMMON LAW
M'Naghten Rule –  is insane if, at the time
of the criminal act, he was laboring under
such a defect of reason, arising from a disease
of the mind, that he
Did not know the nature and quality of the act
he was doing; or
If he did know it, if he did not know that what
he was doing was wrong (i.e. he did not know
the difference between right and wrong).
Irresistible impulse test - that states that 
was insane if
She acted from an irresistible and
uncontrollable impulse;
She lost the power to choose between right
and wrong and to avoid doing the act in
question, as that her free agency was at the
time destroyed; or
The 's will … has been otherwise than
voluntarily so completely destroyed that her
actions are not subject to it, but are beyond her
control.
Pure cognitive test concerned with 's ability
to appreciate the nature and quality of his
conduct. Is the current law
C.
MPC
Substansial capacity- One is not
responsible for her criminal conduct if,
at the time of the act, as a result of a
mental disease or defect:
 lacked substantial capacity to
Appreciate the
wrongfulness/criminality of  conduct
or
To conform  conduct to the
requirements of the law
DIFFERENCES
MPC incorporates a revised
version of the M'Naghten test +
pure cognitive test.
MPC
Must negate the mental state required
to establish any element of the offense.
DIFFERENCES
 steals diamonds believing
they’re glass - MPC  petty
larceny; CL  grand larceny.
 steals glass believing it‘s
diamonds, MPC  petty
larceny and attempted grand
larceny and CL  petty larceny
and attempted grand larceny.
MPC – Look at the world
through the ’s eyes in a factual
(not legal) manner
MPC/CL - No mistakes get you
off for strict liability.
GENERAL
1. MISTAKE
a. OF FACT
COMMON LAW
Must negate mens rea of the crime charged. .
 not guilty if MoF negates the specific intent
portion of the offense.
For general intent offenses not guilty if MoF
was honest and reasonable. Guilty if MoF
was honest, but unreasonable
Moral Wrong test – If granted MoF, will hold
 for a higher offense when were the situation
as he supposed it to be, his conduct
constituted this lesser offense.
b. OF LAW
COMMON LAW
No defense, but exceptions.
Exceptions - mistake must be reasonable and
honest.
Collateral Law
Reliance on Official Statement
No reasonable notification/publishing
Logical Relevance Test - figure out the
mens rea for each and every element of
the crime.
If granted MoF, will hold  for a lesser
offense when were the situation as he
supposed it to be, his conduct
constituted this lesser offense.
MPC
MPC does not recognize a defense of
mistake of law unless there is express
negation
Specification in Statute that knowledge
of law is req’d.
Collateral Law
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DIFFERENCES
CL and MPC approaches are
similar. In general, unless
falling into a recognized
exception, ignorance of the law
is no defense.
MPC codifies the CL
Specification in Statute that knowledge of law
is req’d.
Reliance on Official Statement
No reasonable notification/publishing
reasonable reliance doctrine.
MPC
Same as common law.
DIFFERENCES
MPC
Same as common law. No Hybrid legal
impossibility. (MPC looks at mens rea)
DIFFERENCES
2. IMPOSSIBILITY
a. OF FACT
COMMON LAW
None; that is, the person who tries to shoot
someone with a water gun, thinking it was a
real gun, would not have a defense of factual
impossibility. If the facts were as he believed
them to be the victim would be dead. Some
cases look like factual impossibility but are
not; ex. man attempts to kill victim with
voodoo doll. While this is impossible, it is
inherently impossible, not per se factually
impossible; in the voodoo case the victim
would still be alive if the facts were as he
supposed them.
b. OF LAW
COMMON LAW
Cannot punish for a crime that is not a crime.
Hybrid legal impossibility - Where the actors
goal is illegal but impossible due to a factual
mistake of a legal status of an attendant
circumstance. ie. Man has sex with girl
thinking she is 15 when she is really 18.
Some courts recognize this se
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