As most of us know, mental incompetence is a defense commonly relied upon in criminal actions. We often hear about criminal defendants pleading not guilty by reason of mental incompetence. However, this defense cannot serve to insulate an individual from civil liability for damages arising from their actions or inactions. When faced with this issue, Pennsylvania courts have held that mental deficiency does not relieve an individual from civil liability for conduct that does not conform to the standard of a reasonable person. In setting this standard, Pennsylvania courts have reasoned that it is more just to force a mentally deficient defendant to bear the loss suffered by an innocent plaintiff than to leave the innocent plaintiff with no recovery for their injuries. See Priese v. Clement, 70 Pa. D. & C.2d 47 (CCP Delaware County 1974).
To put this distinction in context, let’s assume that a defendant suffering from Alzheimer’s commits an assault upon an innocent plaintiff. This defendant may rely upon their mental incompetence as a defense to criminal charges for assault, asserting that they were unable to form the requisite intent to commit a criminal assault as a result of their Alzheimer’s. However, if the plaintiff elects to pursue a civil assault claim against the same defendant in an effort to recover monetary damages for their injuries, the defendant will be unable to rely upon their Alzheimer’s as a defense. In the civil context, this defendant will be held to the standard of a reasonable person despite their mental deficiency.