Criminal Responsibility

Mental health professionals are often called upon to assess criminal defendants to aid the legal system in determining whether these individuals might have been legally insane (i.e., not criminally responsible) at the time of their offenses. This section delves into the legal concept of criminal responsibility and the criteria for insanity, as well as the challenges faced by forensic experts in conducting these assessments.

In contemporary Western societies, prohibited behaviors are typically defined within the framework of criminal law, and most individuals are considered responsible for adhering to these laws. Those who transgress the law may face prosecution and, if convicted, receive punishment for their actions. Such individuals are deemed “criminally responsible,” signifying a moral and legal judgment that they had no valid justification or excuse for their conduct, should have known better, and must undergo punishment as a corrective measure intended to deter future transgressions.

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However, as the last sentence implies, behavior that may initially appear criminal may, in certain circumstances, not warrant the legal and moral conclusion that the actor is “guilty” or “criminally responsible.” For instance, while taking another person’s life is generally unlawful, doing so in self-defense (where the victim posed a threat to the actor’s life) may constitute a valid justification that negates a finding of guilt. Similarly, the act of taking money from someone (robbery) under duress (where a third party threatens to harm the actor’s child unless the money is taken) might be viewed as justified due to the greater harm (the child’s death) that was averted by robbing the victim.

There are also individuals or groups who may be exempted or excused from being deemed “criminally responsible.” This exemption is not due to extraordinary or justifying circumstances but rather stems from individual characteristics or traits that render them, in society’s judgment, incapable of making the requisite moral and legal judgments needed for appropriate behavior. Additionally, they may be seen as incapable of benefiting from punishment as a corrective measure. For our discussion, we will mention two such groups, both of which have been acknowledged in Western cultures for centuries as inappropriate subjects for moral and legal culpability judgments.

The first category of individuals is children, who, due to their young age, limited life experiences, and mental or emotional immaturity, are not considered morally accountable in the same way as adults. Although exceptional cases may exist, the law typically operates on the presumption that children aged 7 years and younger cannot be held to adult standards of criminal responsibility. For those between the ages of 7 and 14 years, there is a presumption that they are not moral agents to be held to the same adult standards of criminal responsibility, though this presumption can be challenged.

The second group or class of individuals, and the primary focus here, consists of individuals with significant mental disorders whose symptoms contribute to their “criminal behavior” in specific ways that society deems excuses them from moral culpability (criminal responsibility). In legal terms, these individuals are often regarded as “legally insane” or “not guilty by reason of insanity.”

The insanity defense is generally met with disapproval in public opinion, often due to misconceptions about its frequency and success rate. Surveys indicate that the public tends to believe that the insanity defense is both commonly used and frequently successful. However, these beliefs are likely distorted and influenced by the extensive media coverage of high-profile cases involving individuals such as Patty Hearst, David Berkowitz (“Son of Sam”), Jeffrey Dahmer (none of whom were found legally insane), and John Hinckley (who was judged as legally insane). In reality, neither of these beliefs holds true. Research demonstrates that the insanity defense is invoked in less than half of 1% of criminal cases, and it often does not succeed. Furthermore, when the insanity defense is successful, it is typically not due to clever lawyers misleading unsuspecting jurors. Most successful insanity defenses are not seriously challenged by the prosecution; more often, it is evident to all parties involved that the defendant was legally insane at the time of the offense (according to criteria discussed below) and should not be held legally or morally responsible for their actions. Consequently, many successful insanity defenses result from plea agreements.

The subsequent sections explore (a) the criteria for establishing legal insanity, (b) the legal considerations used to determine when a defendant meets these criteria, and (c) the methodologies employed by mental health professionals to collect evidence and formulate opinions regarding a defendant’s mental state at the time of an offense.

Criteria for Legal Insanity

The criteria for legal insanity have evolved over time within the context of Western law. Historians of Western law often attribute the introduction of notions related to mental capacity and intent to Henry de Bracton, whose writings on English law in the 13th century played a significant role in discussions about guilt and moral culpability. Early legal language referred to concepts like “infancy” or cognitive capacity not significantly different from that of a “wild beast” as potentially exculpatory mental states. One of the most influential English cases that shaped the concept of legal insanity was the M’Naghten case in 1843. This case established the test for insanity as follows: the accused was considered insane if they were laboring under such a defect of reason, resulting from a disease of the mind, that they did not know the nature and quality of the act they were committing, or if they did know it, they did not know it was wrong.

The M’Naghten case emphasized impairment in an individual’s ability to “reason” or “know,” making assessments of a defendant’s cognitive abilities central to the legal determination of insanity. This emphasis has persisted in modern formulations, which often refer to a defendant’s “ability to appreciate the wrongfulness of their conduct.” However, as modern psychiatry has influenced the legal field, there has been a growing recognition of volitional impairments as potential bases for legal insanity. Consequently, in some jurisdictions, formulations now consider insanity resulting from criminal behavior that was driven by an “irresistible impulse” or impaired capacity “to conform one’s conduct to the requirements of the law,” even in the absence of cognitive impairment.

Furthermore, certain formulations may specify quantitative, though somewhat imprecise, levels of impairment that must be established to meet the insanity test. For instance, it may be required to prove not just “impaired capacity” but “substantially impaired capacity” for a defendant to be excused from criminal responsibility for their behavior.

The Calculus of Legal Tests for Insanity

In jurisdictions where the insanity defense is applicable, judges and juries are tasked with applying the relevant legal test, which typically follows a structured framework that involves three key findings by the trier of fact.

First, there is a requirement that the defendant was suffering from a predicate mental condition at the time of the offense. In the M’Naghten formulation mentioned earlier, the essential condition is a “disease of the mind.” More contemporary formulations use language such as the presence of a “mental disease or defect.” It’s important to emphasize that, in almost all legal formulations, the definition of the predicate mental condition is not highly precise and is not explicitly tied to clinically recognized categories of mental illness or other mental impairments. However, it’s worth noting that many jurisdictions explicitly prohibit certain clinical conditions as a basis for an insanity defense. These typically include states of intoxication resulting from voluntarily consumed drugs or alcohol and conditions primarily defined based on a history of antisocial behavior, such as antisocial personality disorder or sociopathy.

The second component of the legal test focuses on whether the criminal act was influenced by, or in loose terms, “caused” by the predicate mental condition. Simply having a “disease of the mind” or a “mental disease or defect” is insufficient on its own to excuse the defendant from criminal responsibility. People with mental illness may commit crimes for reasons that are not necessarily related to their mental condition; for instance, they might steal out of greed, engage in a fight because of anger, or drive recklessly because of intoxication. To successfully mount an insanity defense, it must be demonstrated that the mental impairment contributed to the commission of the criminal behavior.

Finally, the connection between the predicate mental impairment and the criminal behavior must specifically align with what is stipulated in the legal test. As previously mentioned, the test for insanity can vary depending on the legal jurisdiction and may refer to either cognitive or volitional impairments.

Consider a scenario where an individual with a well-documented diagnosis of generalized anxiety disorder, which qualifies as a “mental disease,” suddenly experiences extreme anxiety in a situation where the only apparent means of escape is to take another person’s car and drive away. In this situation, the individual is not confused about the ownership of the car (they “know” it belongs to someone else), does not believe they have permission to take the car (they do not have an illness-related delusion granting them authority), and is fully aware of the potential legal consequences, perhaps even experiencing conscious anxiety about the possibility of being arrested for taking the car.

Under a purely cognitive insanity formulation that emphasizes “knowing” or “appreciating” the wrongfulness of one’s behavior, it may appear that the individual’s mental illness (acute anxiety symptoms), even though it motivated the decision to take the car, did not impair their cognitive abilities in the manner required by the legal test. However, under a volitional formulation that addresses impaired impulse control or the capacity to conform conduct, the sudden and intense urge to flee, arguably influenced by the anxiety disorder, might support a finding of insanity.

This illustrates how the specific type of mental impairment, whether cognitive or volitional, as mandated by the legal test, can significantly impact the determination of legal insanity in a given case.

Clinical Assessment of Criminal Responsibility

When the defense opts to pursue a plea of insanity, mental health professionals, often psychiatrists or psychologists, are retained by both the prosecution and defense, or appointed by the court, to assess the defendant’s mental state and provide reports and testimony regarding their criminal responsibility. This type of evaluation presents unique challenges for mental health professionals in their capacity as forensic examiners, distinct from their routine clinical evaluations in non-legal settings.

Even under optimal conditions, clinical diagnostic assessments have inherent imperfections. These assessments typically occur in situations where the clinician works with a willing, candid, and voluntary client, with the primary focus being on their present mental functioning and treatment planning. However, when conducting evaluations for criminal responsibility, such ideal conditions are rarely met. The insanity evaluation is narrowly focused on a specific point in the past, which inherently limits the utility of conventional clinical measures, including psychological tests or other diagnostic procedures. Instead, assessments of criminal responsibility rely heavily on the examination of investigative evidence collected by law enforcement, interviews with defendants, and information obtained from third parties who possess relevant knowledge about the defendant’s behavior and state of mind at or around the time of the offense. Consequently, the conceptual model for criminal responsibility evaluations leans more towards investigative reporting than traditional clinical assessment.

Conducting assessments of criminal responsibility presents several notable challenges, including the following:

The Evaluation Is Retrospective

Insanity evaluations often take place weeks or even months after the defendant’s arrest. Moreover, if the arrest follows a lengthy investigation, the interval between the crime and the clinical evaluation can be significantly extended. During this time gap, various factors can distort the reconstructed image of the defendant’s mental state at the time of the offense. These factors include:

  1. Deterioration of Mental Illness: If the defendant has a mental illness that has worsened over time, the clinician may interview them when they are in a more disturbed state. As a result, the clinician might attribute more psychopathological symptoms to the time of the offense than were actually present.
  2. Improvement in Mental Illness: Conversely, if the defendant’s mental illness has improved, either spontaneously or due to treatment received (e.g., in jail), the clinician may interview them when they are in a less disturbed state. This could lead to the clinician attributing fewer psychopathological symptoms to the time of the offense than were actually present.
  3. Development of Post-Offense Symptoms: Although not symptomatic at the time of the offense, the defendant may have developed symptoms subsequent to the crime. These symptoms could arise as reactions to the nature of the crime itself, events occurring during arrest or in jail, or anticipation of severe consequences. The clinician might mistakenly attribute some of this symptomatology to the time of the offense.
  4. Memory Deterioration: Information gathered through interviews with the defendant or third-party sources, even if provided honestly, can become less accurate over time due to the natural deterioration of memory.

These factors underscore the complexities of conducting retrospective insanity evaluations and the challenges in arriving at an accurate understanding of the defendant’s mental state at the time of the offense.

Concerns about Information Validity

In insanity evaluations, concerns about the validity of information are heightened compared to standard clinical assessments, largely due to the personal or professional interests of the individuals providing information to the forensic examiner. Several factors contribute to these concerns:

  1. Defendant’s Motivation: A defendant facing a lengthy prison sentence may perceive a successful insanity defense as the only way to avoid it. Consequently, they might be motivated to exaggerate or fabricate symptoms of mental disorder when describing their behavior and motivations at the time of the offense.
  2. Family Member Biases: Family members who sympathize with the defendant’s situation may distort information to align with what they believe will be helpful to the case.
  3. Selective Information Sharing: Attorneys involved in the case may selectively present investigative information to the clinician, withholding details they think could lead to an unfavorable opinion.
  4. Police Evidence Presentation: Evidence gathered and provided by the police can also create a misleading image of the defendant’s prior mental functioning. For instance, a mentally confused and verbally incoherent defendant might be convinced to sign a “confession” drafted in clear and organized language by an arresting officer, concealing the extent of psychopathology present at the time of arrest.

These various motivations and interests can compromise the accuracy and reliability of the information available to the forensic examiner, making it challenging to arrive at an objective assessment of the defendant’s mental state at the time of the offense.

Translating Clinical Findings for Legal Consumers

Forensic examiners face the complex task of translating clinical findings into terms that are comprehensible within the legal framework. However, this process is far from straightforward due to the disparity between clinically recognized mental disorders and legal definitions, as well as the qualitative and quantitative nature of legal criteria for insanity.

Clinical mental disorders range from relatively mild conditions like nicotine use disorder to severely incapacitating disorders like schizophrenia or manic disorder. These clinical conditions do not have direct counterparts in legal terms such as “disease of the mind” or “mental disease or defect.”

Furthermore, the legal criteria for insanity require assessments of both the nature of the functional legal impairment (e.g., the ability to “know” or “appreciate” the wrongfulness of conduct) and the extent of impairment (e.g., categorically “did not know” vs. “lacked substantial capacity to know”). These criteria lack a scientific or clinical basis for precise translation.

The absence of a scientific basis for translating clinical findings into specific legal conclusions presents a challenge to forensic examiners. They may face pressure from attorneys and courts to provide definitive opinions based on “reasonable medical (or scientific) certainty.” However, mental health professionals do not possess instruments or methods, like “capacimeters,” to determine whether the specific nature or extent of impairment in a particular case is adequate to excuse the defendant from their moral obligation to obey the law. These constructs are legal terms of art, and their meaning is determined solely through the social and moral judgment of the judge or jury during the verdict. The legal status of an individual being “legally insane” (i.e., “not criminally responsible”) is a social construction that derives its meaning from the jury’s pronouncement and has no inherent meaning before or outside of this legal context.

Forensic examiners play a crucial role in assisting legal decision makers without imposing their own moral judgments under the guise of scientific expertise. While clinical evaluations of criminal responsibility can be valuable, the challenge lies in presenting information relevant to a defendant’s legal functioning in a way that helps the triers of fact make their ultimate judgments.

To illustrate this, consider a case where a defendant with a well-documented history of mental disorder experienced delusional beliefs, such as believing he had been appointed as the deputy director of the FBI, despite being a factory worker for 20 years. Acting on these delusions, he unlawfully took control of a Greyhound bus, believing he was urgently needed in Washington, D.C., for matters of national security.

In this scenario, a forensic examiner might report that, at the time of the offense, the defendant exhibited symptoms (delusions) consistent with a diagnosed mental disorder (schizophrenia) that he had lived with for years. The report would highlight how these symptoms distorted his perception of reality, specifically regarding his occupation and the authority to commandeer a public transportation vehicle. However, the report would not offer a conclusive opinion on whether the defendant’s symptoms meet the required legal criteria (“he suffered from a mental disease”), nor would it provide a definitive opinion on whether the symptoms categorically did or did not relate to the criminal act in the prescribed legal manner (“he did not know that what he was doing was wrong”).

Instead, the formulation would offer a plausible account of the relationship between the defendant’s symptoms and his criminal behavior, leaving it to the jury to make the connections based on their collective social and moral intuitions regarding whether an individual experiencing such disturbances should be held criminally responsible. The forensic examiner’s role is to provide information and context, allowing the legal system to reach its own judgments.


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