This article reviews new research indicating forensic evaluators operate with a high degree of accuracy. The research used a mathematical model to assess the findings of a group of forensic psychiatists, who offered opinions on 156 cases. The researchers found the evaluators distinguished competent from incompetent defendants 29 out of 30 times. From the article:
In an average of 29 out of every 30 cases, the psychiatrists could distinguish competent defendants from incompetent defendants. That’s a level of performance that exceeds standard diagnostic performance in other areas of medicine, such as spotting breast cancer in mammograms or using advanced imaging methods to detect Alzheimer’s disease.
What I also like about this research is the recognition of the difficulties in providing "Yes/No" responses, as psycho-legal issues generally require, when one is dealing with a particularly complicated case. It is perfectly reasonable for two experts to examine the same data, yet ultimately arrive at different opinions, when the data is complex, scattered, etc. There is not a single line separating competency versus incompetency to stand trial, or with other psycho-legal issues; there are cases where defendants fall somewhere in the middle. As the article states:
“These results help us see how courtroom experts can be quite accurate in distinguishing competence from incompetence, but still reach different conclusions,” says Mossman of the study, which was published online in Law and Human Behavior, the journal of the American Psychology-Law Society. “It’s a matter of where experts draw the line on the issue of competence.”
Continues Mossman: “Experts may disagree with each other even though they are very good at making all the right distinctions. You’re apt to get disagreement when you ask experts for a ‘yes’ or ‘no’ answer, as the courts do, on issues that can have gray areas, like competence to stand trial.”
This is not to say there isn't the occasional individual who tends to find in one direction or the other more frequently, for whatever reason. However, the notion that virtually all evaluators already have their minds made up is nonsense. In addition, as the methods available to assess defendants continues to improve, it will become increasingly difficult to defend and outlying opinion. Foresnic evaluations are far more data-driven than in the past, and more scientific in general; as a result, an opinion isn't worth much unless an expert can back it up on the stand. A thorough evaluation, addressing the pertinent questions, explaining the findings in a way that makes sense to everyone in the courtroom, and being honest pretty much addresses these issues.