You have likely heard of the “insanity defense” being used in a criminal trial, the basis of which is the claim by the defense that at the time of the commission of the alleged crime the accused was unable to understand the difference between right and wrong. But there is another way in which the defendant’s mental state can play an important role in the outcome of a trial, only this time before the trial begins: it is the question of “competence.”

Occasionally, the behavior of someone accused of a crime can be so unusual or even bizarre that it becomes questionable as to whether he or she is of sound enough mind not only to assist a defense attorney, but even to grasp the nature of the charges. It has been the policy of courts dating back to old common law that if a defendant is that out of touch with what is happening, having a trial would be pointless.

Take, for example, a recent case in Oklahoma County involving a man who allegedly killed his own father by repeatedly stabbing him at a fast food restaurant. He admitted to doing so, but at the same time claimed in a court hearing that he was a paid killer who was hired to do so as part of a “military operation.” A psychiatrist has diagnosed him as being subject to paranoid delusions; this raises the question of whether he would be competent to stand trial for murder, although the same psychiatrist has claimed that with treatment the accused killer eventually may become competent.

How is competence to stand trial decided?

Court competency deliberations will often involve multiple mental health professionals engaged by the prosecution and the defense. Either the defense or the prosecution can raise competency as an issue by a pretrial motion, but the judge in the case can initiate a competency examination on his or her own initiative. It is up to the defendant to demonstrate by a “preponderance of the evidence” — meaning, that it is more likely than not — that he or she is not competent to stand trial. Oklahoma law used to require that the defendant prove incompetence by “clear and convincing” evidence, but this standard was struck down by the U.S. Supreme Court as imposing too high a burden.

Because competency to stand trial relates to the same fundamental question as the insanity defense — the ability of the defendant to understand right from wrong — it is not uncommon to see both issues raised when one of them is. An important distinction between competency and the defense of insanity is that competency is determined based on the state of mind of the accused at the time he or she is being mentally examined, while the insanity defense looks to the state of mind of the accused when the alleged crime was committed.

It is up to the judge hearing the case to decide whether the accused is competent, and the judge has the discretion to postpone a criminal prosecution while that person is given mental treatment that might render him or her competent to stand trial. If the judge finally decides that the defendant cannot become legally competent, usually that person will be committed to a mental health facility; to proceed to trial against a person who is incompetent to stand trial would be a violation of his or her due process rights.

Are there other forms of “competence”?

Note that competence is not confined to the question of whether the accused is fit to stand trial. Competency can also become an issue in situations where the defendant is able to properly plead guilty to a crime, as well as whether the defendant is able to understand why he or she is subject to execution and what effect it will have in death penalty cases.