Criminal Responsibility, Historical Concepts

The precise definition of criminal responsibility varies from place to place but, in general, to be responsible for a criminal act implies the perpetrator must understand what they are doing and that it is wrong. Clearly, most young children are too immature to fully appreciate the difference between right and wrong. Most countries have fixed an age below which a child cannot be held criminally responsible for their actions. Commonly this is set at ten years, although the age of criminal responsibility can vary between six and 12 years.

An individual may also not be held responsible for their crimes on grounds of mental disorder. It has long been recognized that some people do not have control over or understanding of their actions and the issue of criminal responsibility has been a subject of debate since ancient times. A landmark case occurred in 1843, when Daniel M'Naghten shot and killed the secretary to Britain's Prime Minister Robert Peel. The medical evidence found M'Naghten to be insane. This led to the famous M'Naghten Rule where someone could evade criminal responsibility if it could be proved that they did not understand the "nature and quality" of the act they were committing. Equally, they were not held responsible if they did understand what they were doing, but did not appreciate that it was wrong.

Over the years, there has been much discussion over the meaning of these terms. In countries or states that do not have the death penalty, the difference between being found guilty and responsible and guilty and not responsible is a prison term or a stay in a mental institution. Where the death penalty applies, it may mean the difference between death and life. In March 2005, the United States Supreme Court ruled that while persons under the age of 18-years-old can be held responsible for crimes and punished by imprisonment, they are not subject to the death penalty for crimes committed while under the age of 18.

There are many situations in which someone may not be responsible for their actions. Psychosis may mean they were out of touch with reality at the time of the crime. Criminals suffering from schizophrenia may cite "inner voices" driving them to murder someone. Disorders of impulse control may mean someone is unable to stop himself or herself from attacking someone. People whose actions and judgment are affected by prescription drugs may also not be fully responsible. Crimes with no apparent or rational motive may also be committed by those who are not fully responsible for their actions.

The forensic psychiatrist will examine the accused and will also look for evidence of whether he or she understood what they were doing was wrong. Wearing gloves or a mask or giving a false alibi or name are all clear indicators of knowing a criminal act is being committed. Suspects who dispose of evidence, flee the scene, or lie to police are also likely to appreciate that they are doing wrong. Some criminals can be very manipulative and may feign mental illness, thinking that a stay in a mental hospital is preferable to prison or, indeed, the death sentence. It is up to the forensic psychiatrist to examine all the evidence and the suspect and then to assess if the suspect is, or is not, responsible for the crime.

see also Ethical issues; Psychological profile; Psychopathic personality.