Testimony from Police Inspector John Matthew Tierney at the Trial of Daniel M’Naughten (1843):
“”I suppose you will assign some reason this morning to the Magistrate for the act you have committed?”—he said he would, a short one—I said, “For that matter, you might have stated anything you chose last night after the caution I have given you”—he then said he was the object of a persecution by the Tories, or Tory persecution, or something of that sort—that they followed him from place to place with their persecution—he seemed inclined to go on—I said, (merely to turn the conversation, I did not want to hear the confession,) “I suppose you are aware of the gentleman you have shot at?”—he said, “It is Sir Robert Peel, is not it?”—I said, for the moment, “No,” and then retracted, and said, “We don’t exactly know who it is yet, but recollect the caution I gave you last night, not to say anything that might be used in evidence against you”—he replied, “But you won’t use this against me?”—I said, “I will make no promise, I gave you a caution” (emphasis added)
(Inspector Tierney reading from his written statement later in the trial)
(read)—”The prisoner after being cautioned as to his statement, says, ‘The Tories in my native city have driven me to this, and have followed me to France, Scotland, and other parts; I can get no sleep from the system they pursue towards me; I believe I am driven into a consumption by them; they wish to murder me. That is all I wish to say at present; they have completely disordered me, and I am quite a different man before they commenced this annoyance towards me.’ ”
The defense presented multiple witnesses to M’Naughten’s strange behavior leading up to the crime. The prosecution had no rebuttal for this evidence and offered no evidence of their own regarding his sanity.
According to wikipedia, “When the prosecution declined to produce any medical witnesses to counter this evidence, the trial was halted. Follet then made a brief, apologetic closing speech which he concluded with the words “I cannot press for a verdict against the prisoner…”. Chief Justice Tindal, in his summing up, stressed that the medical evidence was all on one side, and reminded the jury that if they found the prisoner not guilty on the ground of insanity, proper care would be taken of him. The jury, without retiring, duly returned a verdict of not guilty on the ground of insanity. (emphasis added)
These are hardly the jury instructions one might hear today in a case where the insanity defense is put forth.
It is interesting to note that M’Naughten was under the impression he had shot the Prime Minister, Edward Peel. It was many years later and another attempted assassination (Hinkley/Reagan) that would lead to changes and limitations put on the insanity defense.
Chief among those new rules would be Federal Rule of Evidence 704(b) which now states:
“No expert witness testifying with respect to the mental state or condition of a defendant in a criminal case may state an opinion or inference as to whether the defendant did or did not have the mental state or condition constituting an element of the crime charged or of a defense thereto. Such ultimate issues are matters for the trier of fact alone.”
The previous version of this rule stated:
“Testimony in the form of an opinion or inference otherwise admissible is not objectionable because it embraces an ultimate issue to be decided by the trier of fact.”
And, in the the misleading headline department, there is this: Pre-Cog is Real – New Software Stops Crime Before It Happens