Criminal law (2022): Crimes against the person: Murder (Part Two)

Victim.

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, expressly mentioned a fetus as being capable of being killed, and 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. This holding has two implications. Firstly, a defendant in California can be convicted of murder for killing a fetus which the mother herself could have terminated without committing a crime. And secondly, as stated by Justice Stanley Mosk in his dissent, 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.

Mitigating circumstances.

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.

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 defense of "not guilty by reason of insanity" may be used to get a not guilty verdict. This defense has two elements:

That the defendant had a serious mental illness, disease, or defect.

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.

Under New York law, for example:

§ 40.15 Mental disease or defect. In any prosecution for an offense, it is an affirmative defense 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