These two issues are often confused by the general public. Interestingly, the public is far more aware of the issues surrounding the insanity defense than of competency to stand trial, even though competency evaluations are far more common. This is due to the high profile nature of some of the sanity defense cases, as well as the perceived nature of the “higher stakes” involved in the sanity defense (i.e. the defendant will “get off” if found not guilty by reason of insanity, versus simply being restored to competency if found incompetent).
The Dusky definition of competency to stand trial specifically refers to present ability to stand trial. In other words, how they are doing right now. It has nothing to do with how the defendant was functioning at the time of the offense, which is what the sanity defense is concerned with. In other words, competency to stand trial is concerned with the defendant’s abilities during the time frame of the trial, not prior to the trial (to include the time of the alleged crime). While obtaining an overall history of the defendant’s mental health is generally considered a part of a thorough competency evaluation, a specific inquiry into the defendant’s state of mind at the time of the offense is not only unnecessary, but also inappropriate. These are two entirely separate evaluations, and in a perfect world, are generally treated as such. When I evaluate a defendant for competency to stand trial, I will ask the defendant enough questions about their understanding of the charges against them, what happened when they were arrested, etc. in order to be able to assess whether they have the capacity to assist in their defense, but no more. In fact, nothing a defendant says during a competency evaluation should be included in the report if it is incriminating. A statement such as, “The defendant demonstrated a reasonable recall of the circumstances of his arrest,” is more than enough to address that specific question regarding competency.
Not living in a perfect world, here is the exception. I often receive court orders for both types of evaluations, competency to stand trial and sanity at the time of the offense, to be evaluated at the same time. I wish this wasn’t done, because I truly believe that the issue of competency ought to be addressed prior to a trial proceeding, but really, no one cares what I think. Therefore, I do both. But the procedures are very different, and the information necessary for completion of each type of evaluation is different. Aside from my thinking regarding competency being addressed first, the other issue is “tipping the hand” one way or the other. I just don’t like the idea of either side in a legal case getting an idea about the sanity question prior to the determination of competency (yep, that’s me, silly, naive, altruistic psychologist that yearns for fair, objective trials). There are steps we take as psychologists to avoid this pitfall, but that’s a story for another time.
The more embarrassing issue, from my standpoint, is when psychologists don’t get this distinction. It’s not as bad now, but I remember back 5-10 years ago, reading some reports where the “expert” wrote reports addressing both competency and sanity, often confusing the two, as well as using current information to address sanity, previous information to address competency, etc. First, if psychologists can’t help educate the courts and the public about these issues, who can? Secondly, a report like that ought to be shredded on cross-examination. However, the very worst example I’d ever seen was an evaluation completed by a psychologist based in Denver, who was “the toast” of the judiciary! They loved him, right up until he lost his license...
Anyway, I’ll get more into the whole “sanity defense” issue after I cover competency a bit more thoroughly. For now, simply note one has nothing to do with the other - they are separate legal questions.