Mental State and Crime
“Nature, Mr. Allnut, is
what we are put in this
world to rise above.”
Katherine Hepburn to
Humphrey Bogart,
The African Queen
Offenders by Age and Sex (Britain)
Crime involves:
1. legally proscribed conduct
(actus reus)
2. that causes harm
3. coincides with blameworthy
frame of mind (mens rea)
4. and carries with it punishment
Use of force to repel an imminent,
unprovoked attack, in which
defendant reasonably believes that
s/he or others might be seriously
injured and where there is no
May include defense of property when
it is the home
M’Naghten test
1843 British Case – attempt on life of
Prime Minister, Sir Robert Peel
Defendant must be “laboring under such
a defect of reason, from disease of the
mind, as not to know the nature and
quality of the act he was doing; or, if
he did know it, that he did not know
what he was doing was wrong.”
Irresistible impulse
Defendant must show that:
Mental diseases has deprived the
accused of willpower to resist the
insane impulse
Rather than focus on impaired
mens rea, focuses on impaired
actus reus
Durham rule
Durham v. U.S. (1954)
Defendant must show that unlawful
acts were the product of a mental
disease or defect
Makes standard more medical in
nature, less about moral