The defense of not guilty by reason of insanity (NGRI) represents an integral part of American jurisprudence at present. More than half of the states follow a so-called “M’Naughten” rule of insanity plea when it comes to defending a person, who at the time of a crime committed was unable to think wisely or did not understand that his or her actions were a crime. Normally, whether an accused is sane or insane is determined by the results of the M’Naughten test. The presence of the men’s rea (“guilty mind”) element of a crime, which is directly relevant to criminal intent, is known to have nudged 14 American states to start looking for an alternative to the existing NGRI verdicts and introduce the guilty but mentally ill verdict (GBMI) to the current court system. According to statistical analysis, its introduction has created a suitable environment for mock juries to refer to the alternative 2.5 times as frequently as they do with guilty verdicts (Richie et al., 2014). As an example of the successful use of the insanity plea in the USA, one can bring a court case of 1859 held over Daniel Sickles, who shot Philip Barton Key in Lafayette Park for having a love affair with his wife. During a publicized trial, Sickles claimed temporal insanity evoked by rage. In the same year, he was acquitted of the murder charges and even received the public’s gratitude for killing the adulterer Philip. Regarding the situation in the United Kingdom, the House of Lords accepted a subjective test as a more efficient means to detect the criminal intent, compared to the earlier used “M’Naughten” rules (Helm, Ceci, & Burd, 2016). The criticism of the former testing system (the one that is still used in the USA) reflected the intuitive assumption that the rules were too narrow to include all of those who were mentally ill and needed treatment. In the meantime, an objective test paid attention to the perspective of a reasonable person and not just one’s ability/inability to distinguish the right from the wrong. Basically, it answers the question of whether a reasonable person could predict the degree of probability of the result derived from a defendant’s actions or not. One of the most known insanity defenses, which took place in the United Kingdom court and led to the defendant’s discharge, is a trial course held over Daniel McNaughton. It is known that the accused killed the secretary of the British Prime Minister and was acquitted “by reason of insanity.” Naturally, this case provoked a public uproar, which forced the court to develop a stricter test and change the approach towards the insanity defense. Thus, the newly introduced test was named after the person who became the reason for the overall policy changing. As to the criminal intent situation in Norway, the act of violence, which took place on July 22, 2011, had led to serious changes in the country’s criminal law (Grøndahl & Stridbeck, 2016). Anders Breivik, a middle-class Norwegian from Oslo, shocked his nation by shooting 69 people and bombing the government buildings on the same day. All in all, 77 people were murdered in those tragic events. Nevertheless, Brevik showed no signs of penance for what he did during the court sessions