The Sordid History of Legal Culpability
I was reminded recently while watching an old Brother Cadfael mystery (“The Holy Thief” 1998), that in the “old days”, the justice system left much to be desired. An accused was thrown in the water and if they sank, they were innocent, but if they floated, guilty! The lesson was, apparently, keep lots of rocks in your pockets in case someone pointed the finger at you!
Luckily, we have improved on that method. Instead of body mass, our modern system is based on “volitional culpability”. A person is responsible for the consequences of their actions and decisions made of their own "free will”. Punishment and liability are determined on a sliding scale from the negligent "oops" to the intentional act.
Now to be fair, even in the time of the Brother Cadfael mysteries (the 12th century), “madness” or the inability to appreciate “moral wrongfulness” were defenses to criminal convictions. Of course, so was possession by the devil, but that's another story.
If you want to explore the twisted history of the Insanity Defense in greater depth from its roots in 12th century England, here are two classic articles, from the many out there, one from PBS and one from the American Association of Psychiatry and the Law. Whatever you do, don't miss the era of Phrenology!
Lack of Culpability Defenses: Insanity, Diminished Capacity and DSM 5
Today, the premise of the basic "Insanity Defense" is whether, because of a diagnosed mental condition or defect, a defendant either failed to appreciate the criminality of his/her actions or was unable to act within the law due to the defect/condition. In other words, a person couldn’t tell right from wrong, or if they could, they just couldn’t help themselves. This is basically the Model Penal Code (MPC) version which combines the old "M’Naughton" and "Irresistible Impulse" standards (most states do either the MPC or combine the McNaughton and Irresistible Impulse).
The professional handbook for modern diagnoses is called the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM 5). DSM 5 was the decade plus effort of the American Psychiatry Association to streamline the process of diagnosis for better treatment. The new version also expanded the realm of disorders to include such personality disorders as hoarding and gambling . Completed in 2013, it has met with praise, criticism and controversy. If and until there is a DSM 6, however, DSM 5 is the standard.A person diagnosed with some form of psychosis, severe cognitive/intellectual defect or other DSM 5 recognized issue may qualify for the "Insanity Defense" on the basis of expert testimony.
It should be noted, though, that while the Insanity Defense is a favorite and frequent plot point for TV, movies, and novels, in reality, it's seldom used. Even when used, it's rarely successful. If it is successful, the Insanity Defense is a complete defense to a crime. This means the person will be found not guilty.
The defense of "Diminished Capacity" deserves a mention as it is frequently associated with, and sometimes mistaken for, the Insanity Defense (including Temporary Insanity). The two are quite different legally. A successful use of the "Diminished Capacity" defense would only mitigate the "intent" element of the charge, not the whole charge. In other words, by pleading Diminished Capacity (as opposed to pleading Insanity), the accused might still be found guilty of manslaughter as opposed to murder.
Expert testimony is also required for the Diminished Capacity defense. Although the expert testimony requirement is meant to prevent the use of unrecognized theories such as “road rage”, “sports rage” or “hormone rage” , it hasn't always worked out that way. In fact, there have been several rather creative defenses that have succeeded in mitigating charges.
The Future of Legal Culpability: My Neurons Made Me do It?
What does the future hold in this area? The answer may lie in the rising new discipline of NeuroLaw: the intersection of Neuroscience and Justice. With the increasingly innovative neuro-imaging techniques capable of measuring complex brain activity, researchers are starting to discover what is “normal” and “abnormal”.
The use of brain images and neuroscience in the courtroom is not new in itself. Evidence of physical brain damage and disability through brain imaging as well as expert testimony has been allowed for a long time to prove personal damages and/or victim injury. However, its use in the criminal culpability phase is new. As this article and this one discusses, with the growing role of Neurolaw, the need to resolve legal, ethical, and even philosophical issues will grow as well.
One of the most interesting questions will probably be about "free will". Most of us would like to believe that we are the masters of our own decisions and actions, but there are some noted neuro-experts who suggest free will is a mere illusion. I think I'll just leave that one alone and say that whether free will exists or not, "my neurons made me do it" is not a fully recognized criminal defense. Yet.
Understandably, judges have been reluctant to allow any untested “Neuro-Defense” or "Neuro-Proof of Guilt" by either the defense or prosecution. That’s a good thing. Even with all the new studies, and with a few exceptions, the science still has a ways to go before definitively linking “neural anomalies” to distinctive behaviors. It is hoped that before the courts recognize an "abnormality" as either a legal defense or evidence of guilt, experts would have to show a conclusive connection, not just a correlation, between a particular diagnosis and a criminal action.
Conclusion- For Now
We may have mapped the Human Genome, but we are still years away from completely understanding what all the parts do. This is true in all aspects, including the legal arena. The transition from scientific discovery to legal use should be carefully considered requiring the science to be as reliable as possible before it becomes legally useable.
Think this is just a fantasy concern of the future? See this article discussing the possible use of neuroscience and AI (Artificial Intelligence) for predicting recidivism. Why does the movie Minority Report come to mind?
Even with all the legal system's quirks and imperfections, however, I do believe we've improved over the “sink or swim” approach of the Middle Ages. Having said that, it might still be a good idea to keep a few rocks in your pocket! You know, just in case.