Psychiatric Annals

CME Article 

Autism Spectrum Disorder and Criminal Defense

Alexander R. N. Westphal, MD, PhD; Rachel Loftin, PhD


Autism spectrum disorders (ASD) are defined by a disability in social insight and communication, and the presence of restrictive and repetitive patterns of behavior. Aspects of these diagnostic criteria can be related to behaviors that generate legal problems for people with ASD. Defense strategies, including invoking the concept of counterfeit deviance and the insanity defense, may be considered in the legal representation of people with ASD accused of crimes. [Psychiatr Ann. 2017;47(12):584–587.]


Autism spectrum disorders (ASD) are defined by a disability in social insight and communication, and the presence of restrictive and repetitive patterns of behavior. Aspects of these diagnostic criteria can be related to behaviors that generate legal problems for people with ASD. Defense strategies, including invoking the concept of counterfeit deviance and the insanity defense, may be considered in the legal representation of people with ASD accused of crimes. [Psychiatr Ann. 2017;47(12):584–587.]

Autism spectrum disorder (ASD), defined in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5),1 as a disorder of social communication and interaction coupled with restricted or repetitive patterns of behavior, is primarily a condition of social understanding. The criminal justice system exists to maintain standards of social behavior, and so it should not be surprising that a disability that impairs social insight can result in behaviors that lead to legal trouble.

Descriptions associating ASD with the types of problematic behaviors that can lead to legal involvement date back to the first descriptions of ASD. Asperger2 described four children referred to his clinic because of problematic conduct in school. He described one of the children as: “[He] did not know the meaning of respect and was utterly indifferent to the authority of adults.”2 Asperger concluded that “The nature of these children is revealed most clearly in their behavior towards other people. Indeed, their behavior in the social group is the clearest sign of their disorder.”2

Case Report Literature

In the literature, the overlap between autism and criminal behavior is made up mostly of case reports and reviews that summarize them. Case reports provide only limited information about the nature and extent of the problem, because they most often describe sensational or unusual situations. Sensationalistic news reporting, sometimes masquerading as science, has amplified this problem, drawing attention to single, extreme cases, further undermining efforts to understand the nature of any association between ASD and criminal behaviors. There is some primary research on the topic, but Mouridsen3 concluded that the “results published so far (provide) no basis for addressing whether an association exists between ASD and offending.”

Nevertheless, the case report literature has identified a series of themes, or mechanisms by which ASD can lead to behaviors that can trigger legal problems.4 These include social cognitive deficits, rigid adherence to routines, restricted interests, and sensory hypersensitivity. Each is discussed below, and then the relevance to legal proceedings is considered holistically.

The Defining Features of Autism Spectrum Disorder

The defining feature of ASD is an abnormality of social relatedness. In DSM-5, the abnormality of social relatedness is defined by difficulties with social communication and social interaction across multiple contexts. The DSM-5 gives examples of three broad areas in which social communication and interaction can be impaired. The first, deficits in social-emotional reciprocity, can include “abnormal social approach,” “failure of normal back-and-forth conversation,” “reduced sharing of interests, emotions, or affect,” and “failure to initiate or respond to social interactions.”1

The second, problems with the types of nonverbal communication that are used for social interaction, can include “poorly integrated verbal and nonverbal communication,” “abnormalities in eye contact and body language,” “trouble understanding and using gestures,” and can even include “a total lack of facial expressions and nonverbal communication.”1

The third, deficits in developing, maintaining, and understanding relationships, can include “difficulties adjusting behavior to suit various social contexts,” “difficulties in sharing imaginative play or in making friends,” and an “absence of interest in peers.”1

The Abnormalities of Social Relatedness

Underlying these abnormalities of social relatedness is a disability of understanding the mental states of oneself or others. This social cognitive deficit is sometimes described as a defect in Theory of Mind (ToM) or mentalizing.5 ToM deficits can cause the person with ASD to struggle to understand social cues and to appreciate another's perspective in situations that might be immediately obvious to people without ASD.

Stalking is a good example of how a disability in social cognition can lead to problematic behaviors. The person with ASD might fail to recognize either the nonverbal cues or even clear statements that someone is not interested in his or her social or romantic overtures, and pursue them to the point that authorities get involved. On stalking and ASD, Stokes and Newton6 write “many of the difficulties that individuals with ASDs encounter result from their frequent, eager and sometimes socially inappropriate attempts to make contact with others.” Further, because of ToM deficits, people with ASD may not recognize that the person at the focus of their attention feels fear or anger. There are other ways in which social disability can lead to legal problems; for example, by making people with ASD more vulnerable to manipulation by peers, or by hindering their insight into the way in which their behavior might appear to others.

The Restricted, Repetitive Patterns of Behavior

The other defining feature of ASD is restricted, repetitive patterns of behavior, interests, or activities. The DSM-5 includes four subdomains in this category. The first, “stereotyped or repetitive motor movements, use of objects, or speech” does not generally lead to legal trouble, but can lead to altercations (which could, in turn, lead to police involvement); for example, when a person who is being spoken to thinks that the person with ASD is mocking them by repeating phrases. Motor stereotypies can appear threatening and, inadvertently, a person engaging in repetitive movements of the whole body can strike another person.

The second, “insistence on sameness, inflexible adherence to routines, or ritualized patterns or verbal nonverbal behavior,” can lead to legal problems, for example, when a ritualized or routine behavior is interfered with, and things escalate. Frith7 gave an example of a way in which inflexible adherence to routines could create a problematic situation: “One very small and gentle 25-year-old carried with him for a time a set of police handcuffs so that he could make a citizen's arrest if he spotted unlawful behavior.” The young man's rigidities about enforcing legal codes translated into behavior that could lead to his own legal problems.

The third subdomain is “highly restricted, fixated interests that are abnormal in intensity or focus.”1 Murphy8 discusses the case of Darius McCollum who was arrested and incarcerated multiple times for stealing transit vehicles, including trains and buses. He would sometimes drive the vehicles on its prescribed route, stopping for passengers, and ultimately returning the vehicle. Although stealing involves taking property that does not belong to you without permission and without intention of returning it, McCollum's behavior is rooted not in the desire for possession, but in his restricted, highly focused interest in transit systems. The behavior is further fueled by the absence of checks that intact social insight would provide. The fact that he was incarcerated repeatedly, however, indicates that the legal system believes that these factors are not substantially mitigating; that he should be punished for his actions in the same way that someone who committed the acts for secondary gain.

The fourth, “hyper- or hypo-reactivity to sensory input or unusual interests in sensory aspects of the environment,” can also lead to legal trouble. An example would be when a person with ASD becomes overwhelmed in a crowded, noisy place and acts in an aggressive way. In another example, Schwartz-Watts9 describes a case in which sensory hypersensitivity was thought to be important: “His presenting symptom was intolerance and oversensitivity to a specific noise. As a child, he was unable to tolerate the noise of his parents talking on a telephone downstairs. On hearing this noise, he would become aggressive toward others and bang his head against the wall.”

The Potential Legal Implications of Having Autism Spectrum Disorder

Sometimes both aspects of ASD, the social-communication challenges and the restricted patterns of behavior, can together lead to legal involvement. For example, a young man with ASD and intellectual disability showed a strong interest in odors, particularly perfumes. This interest was pervasive; he hoarded items that smelled strongly, always requested perfumes as gifts, and attempted to smell everyone he met. For example, in a hypothetical clicnial scenario, the fact that he was developmentally delayed was evident from many of his mannerisms, and those he approached generally considered his desire to smell them as humorous but benign and usually did not mind. He was also taught to ask permission before he approached people. However, in one instance in a public place, he approached a young woman and asked for permission to smell her. She was upset by this request, pushed him away, and screamed. He also began to scream. As a result, the police were called, and the young man was arrested. Subsequently, it was established that the young woman felt she was about to be sexually or physically assaulted. In this case, although the behaviors were associated with a special interest, the man's lack of insight into appropriate social behaviors also contributed to the problem.

A common theme that occurs in criminal cases that involve ASD is that the problematic behavior has an alternative root cause than the one that would normally drive the behavior. The case of the young man interested in perfumes, described above, is an example of this. Although the problematic behavior appeared to foreshadow some kind of assault, this was most likely not the case, and in fact the behavior was driven by a less scary, more benign explanation—his interest in smells.

Hingsburger et al.10 used the term counterfeit deviance to describe inappropriate sexual behavior rooted in factors such as sexual and social naivety rather than in true deviance of sexual drive. The concept of counterfeit deviance is applicable beyond sexual behavior, and relevant to several of the situations discussed above. For example, Darius McCollum's behavior (described above) is compulsive and rooted in his restricted, highly focused interest in transit systems. The penalties for this type of behavior, although they are broadly related to the risk, also reflect the assumption that the behavior is voluntary, subject to self-control, and serves some end, beyond a psychological one, which benefits the thief. McCollum can articulate and understand that his actions are wrong, but is unable to control his impulses. In an interview,11 McCollum said, “It's like I'm drawn in…I don't know how to fight that feeling on my own.”

Given that ASD is a biologically based neurodevelopmental condition, when problematic behaviors of the type that McCollum exhibited are considered in the courtroom, the court should also consider whether the condition has a role in driving the behavior. This type of information may be used for mitigation.

In a review by Wauhop,12 cases from Australia, Britain, and the United States were used to discuss mens rea and ASD (specifically Asperger's syndrome). Wauhop12 describes several defense strategies, including failure of proof defense in which evidence is introduced to suggest that the defendant cannot satisfy the mens rea element of the offense. The concept of counterfeit deviance may be relevant to this type of defense if an alternative, noncriminal explanation accounts for the problematic behavior. Wauhop12 also describes a mistake in fact defense: “The effects of [ASD] (especially ‘mindblindness’) can result in conduct based on an honest and reasonable but mistaken belief of facts. Individuals who engage in criminal conduct based on such a ‘mistake-in-fact’ are sometimes excused from culpability.” Finally, Wauhop12 discusses reduced responsibility resulting in mitigation of sentence as a strategy.

Most US states have an insanity defense available, although there are several different standards used. With one exception, states allow the defense to have some sort of wording that relates to the capacity of the defendant to understand the wrongfulness of his or her actions. Some states also have a second aspect of the defense, an irresistible impulse arm. The irresistible impulse captures compulsive actions that are thought to be beyond the person's control and, as such, undermines his or her ability to conform conduct to the law.

These two aspects of the insanity defense line up with the diagnostic criteria for ASD. Understanding the wrongfulness of actions in a social situation, for example, can depend on fully grasping the social implications of the actions. The person accused of stalking, whose behavior was based on failing to read social cues, is an example. The irresistible impulse aspect of the defense may apply when there is an overwhelming compulsion to carry out a specific behavior, as was the case with Darius McCollum. Given the overlap between the ASD criteria and components of insanity, it seems reasonable in our view that an insanity defense could be used for ASD. However, this seems to be a rare occurrence.

Perhaps a fundamental issue is one of vocabulary. Insanity is generally conceptualized as an aspect of psychiatric illness, and usually psychotic illness. In many contexts, the terms psychotic and insane are conflated, or treated as synonyms. Furthermore, psychotic illness, or insanity, can vary with the acuity of the condition and can often be treated. On the other hand, ASD is an immutable, developmental condition. At the time that insanity defenses were evolving, ASD was not on anyone's radar, and it is only recently that people have realized that there may be a special set of considerations that apply to people with ASD in legal trouble.

Even though we note above that the diagnostic criteria for ASD align with both arms of the insanity defense, perhaps the issue is with the name “insanity defense,” rather than the way in which the concept is defined. If the insanity defense were instead called the “mental condition defense” or some other name that moved it away from the outdated concept that psychotic illness alone is severe and disorganizing enough to justify invoking it, we would find that there are other conditions that are as relevant as psychotic illness to legal culpability.


In summary, law is a mechanism by which social behaviors are codified and held to an acceptable standard. ASD undermines social communication and cognition and can also produce urgent compulsions to pursue particular interests and behaviors; consequently, these core features of ASD may be associated with legal trouble. Some of these problematic behaviors may reflect drives and motivations that are quite different from the antisocial drives that the surface behaviors suggest, and their expression may reflect a lack of insight into how the behavior may appear to others. When someone with ASD is charged with committing a crime, health care professionals can often play an important role in the legal process by explaining that behaviors appearing to be driven by personal gain or other antisocial ends might reflect the disability in social thinking and atypical behaviors that define autism. This information may be relevant to mitigation or even to an insanity defense.


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  12. Wauhop B. Mindblindness: three nations approach the special case of the criminally accused individual with Asperger's syndrome. Accessed November 9, 2017.

Alexander R. N. Westphal, MD, PhD, is an Assistant Professor, Division of Law and Psychiatry, Department of Psychiatry, Yale School of Medicine. Rachel Loftin, PhD, is an Associate Professor, Department of Psychiatry, Rush University School of Medicine.

Address correspondence to Alexander R. N. Westphal, MD, PhD, 34 Park Street, Division of Law and Psychiatry, Department of Psychiatry, Yale School of Medicine, New Haven, CT 06519; email:

Disclosure: The authors have no relevant financial relationships to disclose.



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