I asked AI something similar, and here's what it gave me. I'd say this is much more likely to be true (or maybe you didn't see the first part which demonstrates competency evaluations aren't that common). Attorneys ask for a competency evaluation in about 5% of cases and perhaps 25 % of those succeed. That would mean about 1.25% of defendants don't proceed due to competence (but in that case they'd be institutionalized until found competent, except where the crime was fairly minor).
- Referrals: Defense attorneys or judges request competency evaluations in roughly 2% to 8% of felony cases, or an estimated 60,000 to over 120,000+ evaluations nationwide each year. [1, 2, 3]
- Findings of Incompetency: Among the defendants who are actually referred and evaluated for competency, meta-analytic and historical studies show that roughly 20% to 27.5% are ultimately found incompetent to stand trial (IST). More recent local and state-level studies suggest that rates can vary widely (from about 30% up to 50% or higher depending on the jurisdiction and whether minor or misdemeanor charges are included). [1, 2]
- Overall Criminal Population: Out of all people arrested or accused of a crime in the U.S. overall, the percentage found unfit for trial is a small fraction of 1%, because the vast majority of defendants are never referred for a mental competency evaluation. [1]
