Ms. Fox brought him back to UCSF, where neuropsychiatric testing, including a CT scan, showed he had longstanding dementia and a past stroke.

Yes, of all the forensic neuropsychiatric offices in all the towns in the world — the town here is San Francisco — she walks into his.

A stint as a draftee medic in the neuropsychiatric ward at Valley Forge Army Hospital taught him almost as much as all the lessons.