Painful as it is to record the fact, juries are sometimes almost as sceptical in regard to doctors as they always are in regard to lawyers.
The usual effect of the expert testimony on one side is to neutralize that on the other, for there is no practical way for the jury to distinguish between experts, since the foolish ones generally look as learned as the wise ones.

The result is hopeless confusion on the part of the juryman, an inclination to "throw it all out," and a resort to other testimony to help him out of his difficulty.

Of course he has no individual way of telling whether the defendant "knew right from wrong," whatever that may mean, and so the ultimate test that he applies is apt to be whether or not the defendant is really "queer," "nutty" or "bughouse," or some other equally intelligible equivalent far "medically insane." The unfortunate consequence is that there is so general and growing a scepticism about the plea of insanity, entirely apart from its actual merits, that it is difficult in ordinary cases, whatever the jurors may think or say in regard to the matter, to secure twelve men who will give the defence fair consideration at the outset.
This is manifest in frequent expressions from talesmen such as: "I think the defence of insanity is played out," or "I believe everybody is a little insane, anyhow" (very popular and regarded by jurymen as witty), or "Well, I have an idea that when a fellow can't cook up any other defence he claims to be insane." The result is a rather paradoxical situation: The attitude of the ordinary jury in a homicide case, where the defence of insanity is interposed, is usually at the outset one of distrust, and their impulse is to brush the claim aside.

This tendency is strengthened by the legal presumption, which the prosecutor invariably calls to their attention, that the defendant is sane.

Every expert who has testified for the defence in the ordinary "knock down and drag out" homicide case must have felt with the prisoner's attorneys, that it was "up to them" not so much to create a doubt of the defendant's sanity as to prove that he was insane, if they expected consideration from the jury.
Now let us assume that the defence is meritorious and that the prisoner's experts have created a favorable impression.