Victim[edit]
Murder in the House, Jakub Schikaneder.
All jurisdictions require that the victim be a natural person; that is, a human being who was still alive
before being murdered. In other words, under the law one cannot murder a corpse, a corporation, a
non-human animal, or any other non-human organism such as a plant or bacterium.
California's murder statute, Penal Code Section 187, was interpreted by the Supreme Court of
California in 1994 as not requiring any proof of the viability of the fetus as a prerequisite to a murder
conviction.[34] This holding has two implications. The first is a defendant in California can be convicted
of murder for killing a fetus which the mother herself could have terminated without committing a
crime.[34] The second, as stated by Justice Stanley Mosk in his dissent, is that because women
carrying nonviable fetuses may not be visibly pregnant, it may be possible for a defendant to be
convicted of intentionally murdering a person they did not know existed.[34]
Mitigating circumstances[edit]
Some countries allow conditions that "affect the balance of the mind" to be regarded as mitigating
circumstances. This means that a person may be found guilty of "manslaughter" on the basis of
"diminished responsibility" rather than being found guilty of murder, if it can be proved that the killer
was suffering from a condition that affected their judgment at the time. Depression, post-traumatic
stress disorder and medication side-effects are examples of conditions that may be taken into
account when assessing responsibility.
Insanity[edit]
Main articles: Insanity defense and M'Naghten rules
Mental disorder may apply to a wide range of disorders including psychosis caused
by schizophrenia and dementia, and excuse the person from the need to undergo the stress of a trial
as to liability. Usually, sociopathy and other personality disorders are not legally considered insanity,
because of the belief they are the result of free will in many societies. In some jurisdictions, following
the pre-trial hearing to determine the extent of the disorder, the defence of "not guilty by reason of
insanity" may be used to get a not guilty verdict.[35] This defence has two elements:
1. That the defendant had a serious mental illness, disease, or defect.
2. That the defendant's mental condition, at the time of the killing, rendered the perpetrator
unable to determine right from wrong, or that what they were doing was wrong.
Aaron Alexis holding a shotgun during his rampage.
Under New York law, for example:
§ 40.15 Mental disease or defect. In any prosecution for an offense, it is an affirmative defence that
when the defendant engaged in the proscribed conduct, he lacked criminal responsibility by reason
of mental disease or defect. Such lack of criminal responsibility means that at the time of such
conduct, as a result of mental disease or defect, he lacked substantial capacity to know or
appreciate either: 1. The nature and consequences of such conduct; or 2. That such conduct was
wrong.
— N.Y. Penal Law, § 40.15[36]
Under the French Penal Code:
Article 122-1
A person is not criminally liable who, when the act was committed, was suffering from a
psychological or neuropsychological disorder which destroyed his discernment or his ability to
control his actions.
A person who, at the time he acted, was suffering from a psychological or neuropsychological
disorder which reduced his discernment or impeded his ability to control his actions, remains
punishable; however, the court shall take this into account when it decides the penalty and
determines its regime.
Those who successfully argue a defence based on a mental disorder are usually referred to
mandatory clinical treatment until they are certified safe to be released back into the community,
rather than prison.[37] A criminal defendant is often presented with the option of pleading "not guilty by
reason of insanity". Thus, a finding of insanity results in a not-guilty verdict, although the defendant is
placed in a state treatment facility where they could be kept for years or even decades.[38]
Postpartum depression[edit]
Postpartum depression (also known as post-natal depression) is recognized in some countries as a
mitigating factor in cases of infanticide. According to Dr. Susan Friedman, "Two dozen nations have
infanticide laws that decrease the penalty for mothers who kill their children of up to one year of age.
The United States does not have such a law, but mentally ill mothers may plead not guilty by reason
of insanity."[39] In the law of the Republic of Ireland, infanticide was made a separate crime from
murder in 1949, applicable for the mother of a baby under one year old where "the balance of her
mind was disturbed by reason of her not having fully recovered from the effect of giving birth to the
child or by reason of the effect of lactation consequent upon the birth of the child".[40] Since
independence, death sentences for murder in such cases had always been commuted;[41] the new
act was intended "to eliminate all the terrible ritual of the black cap and the solemn words of the
judge pronouncing sentence of death in those cases ... where it is clear to the Court and to
everybody, except perhaps the unfortunate accused, that the sentence will never be carried
out."[42] In Russia, murder of a newborn child by the mother has been separate crime since 1996.[43]
Unintentional[edit]
For a killing to be considered murder in nine out of fifty states in the US, there normally needs to be
an element of intent. A defendant may argue that they took precautions not to kill, that the death
could not have been anticipated, or was unavoidable. As a general
rule, manslaughter[44] constitutes reckless killing, but manslaughter also includes criminally negligent
(i.e. grossly negligent) homicide.[45] Unintentional killing that results from an involuntary action
generally cannot constitute murder.[46] After examining the evidence, a judge or jury (depending on
the jurisdiction) would determine whether the killing was intentional or unintentional.
Diminished capacity[edit]
In those jurisdictions using the Uniform Penal Code, such as California, diminished capacity may be
a defence. For example, Dan White used this defence[47] to obtain a manslaughter conviction, instead
of murder, in the assassination of Mayor George Moscone and Supervisor Harvey Milk. Afterward,
California amended its penal code to provide "As a matter of public policy there shall be no defense
of diminished capacity, diminished responsibility, or irresistible impulse in a criminal action...."[48]
