The government’s last witness against Charles Guiteau was superintendent of the Utica Asylum, Dr. John Gray. During the course of his long career, he had diagnosed and treated about 12,000 insane patients. He did not think Charles Guiteau was insane.
People who are truly insane, explained Gray, believe they are sane but have some type of physical disease that manifests itself in insane behavior. That, claimed Dr. Gray was not the case with the killer of President Garfield:
No man who has such a delusion and is insane, recognizes himself as anything but sane, or recognizes that delusion is anything but an evidence of his insanity. (Trial, page 194.)
Listening to Gray’s testimony, the defendant blurted out:
The idea that a man cannot be insane without he has got a diseased brain is all nonsense...There is not brainology in this case, but it is spiritology. Spirits get into a man and make him do this and that thing, and that is insanity. (Trial, page 196.)
The defense expert, Dr. Edward C. Spitzka, told the jury Guiteau was insane:
I concluded that I had an insane man to deal with on sight, before I asked him any questions. He has got the insane manner as well marked as I have ever seen it in an asylum.
Scoville, for the defense, asked his expert the most important question of all:
Q: Was he insane on the 2nd day of July last, at the time he shot the President?
A: I should say that the prisoner, whom I examined, had been in a more or less morbid state throughout his life, and that he was probably insane at the time you mentioned. (Trial, page 157.)
"Probably insane" wasn’t good enough to save Charles Guiteau.