In Medieval Europe, deciding guilt or innocence was sometimes decided by trial by ordeal. It was believed that the holy water would reject a liar. So they would tie up an accused person and throw him in the water. If you floated, you were guilty. If you drowned, you were innocent.
Has the law evolved much further from this barbaric custom? Many think we have.
In Unfair: The New Science of Criminal Injustice, law professor Adam Benforado begs to differ. He points out that the law of evidence hasn’t caught up with neuroscience. That the way we decide cases isn’t always justifiable. And he gives examples of how we are blind to problematic reasoning.
As we uncover the secret world of detectives, judges, prisoners, and others, we will confront challenging questions. What if our legal rules and practices not only are blind to the real influences on human behaviour but serve to actively perpetuate myths that neuroscientists and psychologists have revealed to be false? What if the structures and frameworks of criminal law that we have adopted to eliminate bias actually make matters worse? And if most people are unfamiliar with the complexities of our hidden minds, might there be power players out there taking advantage of this knowledge to stack the cards in their favour at the expense of the weakest?… Do we care that the path through our system is greased for some and tarred for others, owing to the cognitive biases of police officers, jurors, and judges? Does it matter that certain people are disadvantaged front the outset simply because of their structure of their brain or the shape of their face? … Is justice really blind? [Or is lady justice taking in a lot of information and once she has a picture of you, there’s not much you can do to change it?]… We are masters at jumping to conclusions based on an extremely limited amounts of evidence.
Is it time we rethink the way we establish facts in courtrooms? What role should science have in evidence law?
Interestingly, most rules of evidence are based on judicial decisions. Judges making rulings on a set of facts. They are not rooted in science. They are not thought out by bureaucrats. They are not meticulously updated to keep up with scientific developments. In fact, there is a tension between judges and science.
I remember first entering law school, being surprised that judges did not rely on secondary material, like research papers in coming to conclusions. Rather they were restricted to case law and witnesses. But is that justifiable? How should the scientific method influence judicial decision making? Are the senses really enough to judge a case? How should science and law influence one another?
In Saadati v Moorhead, 2017 SCC 28 the Supreme Court of Canada narrowly considered this question. At issue in the appeal was the necessity of medical expert evidence. The trial judge found that a series of motor vehicle accidents caused the plaintiff psychological injuries. However, no expert evidence was put forth to establish the mental injury.
Ultimately, the Supreme Court welcomed expert evidence. But said it wasn’t necessary to prove mental injury. It also wasn’t necessary to confine a mental injury to a psychiatric disorder.
Justice Brown stated at paragraph 2:
 This Court has, however, never required claimants to show a recognizable psychiatric illness as a precondition to recovery for mental injury. Nor, in my view, would it be desirable for it to do so now… recovery for mental injury does not require proof of a recognizable psychiatric illness. [Requiring proof of psychiatric illness is] premised upon dubious perceptions of psychiatry and of mental illness in general, which Canadian tort law should repudiate…
At paragraph 31, Justice Brown states that confining compensable mental injury to a medical condition is “suspect as a matter of methodology”. And that the categories identified as psychiatric disorders are constantly changing and evolving.
Although I agree that lawyers and judges shouldn’t abdicate their critical thinking to hired guns and that it shouldn’t be necessary to adduce expert evidence to show an injury, I strongly believe that we need to rethink the rules of evidence. The rules of evidence and how we apply these rules need to be grounded in science.
(Views are my own and do not represent the views of any organization.)