Psychology is used in the legal system in many ways, whether it is to assess the competency to stand trial, competency of eyewitness testimony, or asses the dangerousness of the psychopathy (Costano & Costanzo, 2013). In recent years a vast number of defences has used the argument that their clients are incompetent to stand trial or are not criminally responsible due to insanity or other psychological issues whether it be schizophrenia or PTSD, all in attempts for either lighter sentences or complete exoneration. A growing concern among the public has been the reliability and the validity of the psychological tests used in these cases – are the accused really …show more content…
To be charges with a crime, there needs to be two primary components: an involvement in a guilty act and an intent to commit the act. Stemming from the Roman law that held the mentally ill shouldn’t be blameworthy in their crimes, the insanity defense is now a worldwide phenomenon. In the United States and in Canada, the insanity plea requires the defense to show that at the time of the crime, the defendant was unable to distinguish the true nature of his actions (right or wrong) (Costano & Costanzo, 2013). If unable the defense is unable to show that the defendant was mentally impaired at the time of the crime, the prevailing theory is that the defendant used free will when committing the …show more content…
Model Penal Code
This test evaluates if a defendant is diagnosed prior to the incident with a relevant debilitating mental disorder by a mental health professional and if at the time of the crime, the defendant was unable to appreciate the nature of the crime or was unable to follow the rule of the law (Thomson Reuters, n.d.).
2. Irresistible Impulse Test
This test evaluates not only if an individual understood the nature of their actions, but also if the defendant could control their impulses to commit a crime. This is also referred to as the policeman at the elbow test (Thomson Reuters, n.d.). A commonly used explanation of this rule is: If a defendant is to commit a crime, even when the police can see it, the individual is considered to be in mental duress and is not capable of controlling their impulses.
3. M’Naghten Rule
This test focuses on if the defendant knew the nature of the crime or not at the time the guilty act was committed (Tomson Reuters, n.d.). Courts differ as to whether “wrong” refers to a legal or moral wrong doing and in some instances; it is both (Tomson Reuters, n.d.).
4. R-CRAS(Rogers Criminal Responsibility Assessment