Since the late 1970s, Battered Woman Syndrome (BWS) has been used as a specific defense in many criminal cases. Nevertheless, after it was introduced to support claims of insanity and self-defense in spousal homicide cases, some legal, normative, and empirical questions appeared. There is no particular legal Battered Woman Syndrome defense. Instead, if there is evidence about battering and its effects, it may help the jury determine the defendant’s innocence or guilt. In the discussed case of a woman killing her husband in his sleep and then claiming Battered Woman Syndrome as her defense, it is unlikely to be effective. Only if there is strong evidence of sexual or physical symptoms and battering, and a medic proves BWS, there is a chance that it can influence the jury’s decision.
Currently, there are four types of insanity defense, including M’Naghten, Durham, substantial capacity, and irresistible impulse. All these variations have something in common: each of them consists of two elements, and the first one is the same in all types. It requires that at the time the defendant commits the criminal act, he or she has to be suffering from a mental defect. The second elements vary insignificantly; the M’Naghten type of the insanity defense requires the defendant to be unaware of either the criminal act’s quality and nature or that it is wrong. Durham type’s second element requires criminal conduct caused by the mental defect or disease to be excused under the circumstances.
Substantial capacity defines the defendant with mental illness as not being able to either confirm the conduct to the law requirements or evaluate the criminality of his crime. Finally, irresistible impulse requires the defendant not to be able to control his or her actions because of the mental disorder and conduct the crime, even knowing it is wrong. There are cases for which all of these insanity defenses may be used. For example, Sara, who has schizophrenia, decides to kill her children to get them to heaven. When the police come to the scene of the murder, Sarah is sure that God made her do that, and she could not control her actions. In this case, the woman is unaware that this is a crime, and she could not stop herself because of her mental illness.