A few recent cases suggest that this line of argument can work well as a sentence mitigation tool. Last month, an Iowa judge reduced a sentence for child pornography possession from 20 years to seven years, after concluding that Asperger's "might very well explain the number of images" involved in the case. In the United Kingdom, a 21-year-old student with Asperger's was given only four months of jail time for possession of 922 pornographic images of children. (Not all courts have been so sympathetic.)
The same reasoning applies to cases of computer fraud. In August, a California man faced a minimum of six and a half years in prison for a multimillion-dollar computer scam involving a fake trucking company. He and a colleague would take orders for their nonexistent business. Then, using information obtained by hacking into a Department of Transportation Web site, they would take credit for deliveries made by real truck companies. In this case, the man's lawyers argued that his Asperger's disorder drove him to engage in repetitive acts of fraud. They also claimed that his extreme social awkwardness made it impossible for him to have masterminded the conspiracy. ("Some people are more vulnerable than others," said his attorney.) The judge handed down a reduced sentence of less than five years.
McKinnon's supporters have taken this one step further: They claim that he shouldn't be locked up at all, as it would be cruel and unusual to put someone with his social impairments in a conventional prison. In 2007, psychiatrist David Allen published a set of interviews he'd conducted with six British convicts with Asperger's. He concluded that being imprisoned was exceptionally stressful and confusing for them. Each one found interactions with police and prison guards traumatic, and most reported extreme difficulties interacting with other prisoners. Two of Allen's interviewees were so intimidated that they spent much of their time hiding in fear. While evidence of Asperger's defendants experiencing physical abuse in prison is anecdotal, a 2001 report by the National Research Council found that people with developmental disabilities were four to 10 times more likely to be victims of crimes in general.
The problem with this line of reasoning is that it's not clear where else you might put these vulnerable inmates. Traditionally, defendants found not guilty by reason of insanity would be sent to a mental institution. But the drugs and therapy sessions that are prescribed to adults with psychiatric problems aren't likely to help people with a condition like Asperger's, which develops in childhood and never goes away. Andy Thomson, a psychiatrist at the University of Virginia Institute of Law, Psychiatry, and Public Policy, suggests punishing Asperger's criminals with long, supervised probation periods instead.
That's largely how the courts have dealt with autism, which first showed up in criminal cases in the 1950s. Still, the legal system isn't always consistent in its treatment of criminals with developmental disabilities, and the sentences handed down to autistic defendants can vary widely depending on the court. Asperger's may prove even more challenging than autism, because it lacks the well-defined intellectual deficits that make the latter relatively easy to diagnose. How will a judge determine whether a given diagnosis of Asperger's is scientifically valid, let alone decide how the disorder relates to a particular crime? These are two of many questions that the criminal justice system faces as the number of children and adults being diagnosed with Asperger's continues to rise.