Adolescents and adults with autism spectrum disorder (ASD) may come into contact with the criminal justice system (CJS) as victims, witnesses, or perpetrators of alleged criminal activity. It is crucial, therefore, that the CJS is able to respond appropriately when faced with such an individual, who may, if higher functioning, appear to all intents and purpose “normal.” It is equally crucial that carers, families, and health professionals have an understanding of the factors that may lead to CJS involvement such that strategies can be put in place to reduce the risk of unlawful behavior. Whilst it is certainly true that people with ASD are vulnerable to being a victim of crime, much of the literature has been concerned with the risks of perpetration. This is driven, in part at least, by the potentially far reaching consequences for the individual who is accused of a crime. As will be discussed subsequently, despite the lack of clear scientific data regarding the epidemiology and etiology of unlawful behavior among people with ASD, many different factors related to the autism phenotype can theoretically impact on risk, and an understanding of these factors can reduce this risk. Understanding these risk factors can also inform the rehabilitation needs of such individuals, who may not necessarily benefit form the generic forensic mental health services. Moreover, for those already in the CJS, much can be done to ensure that their vulnerability is recognized and managed accordingly.

The aim of this chapter is to summarize the available evidence concerning unlawful behavior among adolescents and adults with ASD in a practically informative way. The term unlawful will be used as an all-encompassing term to capture any behavior that is a transgression of the laws of society (which may be referred to in other texts as “criminal” or “offending” behavior). Whilst these laws may vary from jurisdiction to jurisdiction, there are certain core “rights” and “wrongs” that are universally accepted and therefore are associated with severe consequences across the world. These are primarily those behaviors that result in a victim, i.e., result in harm to another person, and that are therefore deemed “morally” wrong. It is these behaviors, which include harassment and stalking, assault on others of a physical and/or sexual nature, as well as the more serious crime of murder, which will be the focus of this chapter. Other transgressions, such as criminal damage and theft (larceny) that may not necessarily directly harm another person physically but that almost certainly will result in sadness and/or distress on the part of the victim, will also be discussed. Much of the research literature is concerned with adults with a diagnosis of Asperger Syndrome, although the evidence discussed and its conclusions apply equally to other higher functioning individuals on the autism spectrum. In contrast, individuals with lower intellectual capacity are much less likely to be perpetrators of crime (although are probably more likely to be victims). However, for the sake of simplicity, the term ASD will be used throughout. Finally, by “higher functioning” I refer to those individuals whose intellectual capacity is in the normal range (i.e., they are higher functioning as compared with others on the autism spectrum).