From the examination of court-ordered psychiatric evaluations conducted during a seven-year period, a comparison was made of demographic, clinical, and diagnostic differences between a group of defendants evaluated as incompetent to stand trial and a group evaluated as competent. Findings showed the incompetent defendant to be older, more likely to be female, and more often intellectually impaired. Psychiatric diagnoses revealed more severe symptoms of disabling mental illness and a greater likelihood of psychosis. Because a finding of competency or incompetency dictates different legal dispositions, frequently bringing the legal proceedings to a halt and diverting the defendant into the mental health system, clear behavioral and symptomatic criteria for incompetency to stand trial are needed. (Author abstract)