I'm trusting that the defense's burden of proving legal insanity is high and why nationwide, only about 1% of all criminal defendants assert the insanity defense.
I just researched the NGRI defense and it's not any fun. However, I learned enough to know that I prefer the NGRI defense law in the 11 states where the burden is on the state or prosecution.
(In California, the burden is on the defense).
For example, in Colorado where the burden is on the state, the prosecution only has to prove one element (not both) of the McNaghten Rule,
beyond a reasonable doubt:
1) the defendant was capable of distinguishing right from wrong, measured against the societal standard of what is right and wrong,
OR
2) capable of forming criminal intent.
Unless the criminal has a long or ongoing history of severe mental illness, I don't think the typical prosecution necessarily struggles to prove
beyond a reasonable doubt that the defendant was legally sane -- i.e., capable of distinguishing right from wrong, measured by the societal standard.
At least in the Colorado case of Leticia Stauch, accused of murdering her 12-year-old stepson Gannon, I believe there's much public evidence that I think proves she was sane at the time of the murder. Legal insanity isn't like turning a light switch turned on and off, where one day you're sane. and the next day you're not!
As for California, I find NGRI defense a whole different animal, beginning with its application of the McNaghten Rule:
1.1. The McNaghten rule in California
California adopted the McNaghten rule as its legal definition of insanity when voters passed Proposition 8, known as the “Victim’s Bill of Rights,” in 1982.
It is important to note that the California test for whether someone is legally insane only requires the defendant to prove that s/he was incapable of understanding the nature of his/her act OR that s/he was incapable of distinguishing right from wrong—not both.
[Both criteria exclude “moral obliquity, mental depravity, or passion growing out of anger, revenge, hatred, or other motives and kindred evil conditions”].
2.1. “Preponderance of the evidence” standard for the insanity defense
The defendant who pleads the insanity defense is required to prove that s/he was insane when the crime was committed by a
“preponderance of the evidence. ”This means that s/he has to show that it is more likely than not that s/he was insane.
Contrast this to the “beyond a reasonable doubt” standard of proof that the prosecution has to meet when it comes to the defendant’s guilt or innocence. “Beyond a reasonable doubt” means that the evidence is so strong that there is no logical explanation other than that the defendant is guilty.
But even under the preponderance of evidence standard, if the jury feels that neither side has the stronger argument on the insanity defense—that is, if the evidence on both sides is equally strong—then they must rule against the defendant.
3.1. Entering a “dual” plea of “not guilty” and “not guilty by reason of insanity”
The first way to enter a California insanity plea is to enter two pleas – one of “not guilty,” and a second of “not guilty by reason of insanity.”
The first “not guilty” plea means that you did not actually commit the crime with which you were charged. The second plea means that you are asserting that—even if you did commit the crime—you should not be convicted because you were insane when you did so.
If you enter a dual plea, you will make your way through the
California criminal court process as follows: [..]
This process is what is called a “bifurcated trial”—because the question of your guilt and the question of your sanity are dealt with in two separate proceedings.
3.2. Sanity hearings in California
During the sanity hearing, the defendant presents expert witnesses—usually psychiatrists—who testify that at the time of the offense, the defendant either
- didn’t understand the nature of his/her act, or
- didn’t understand that the act was wrong.
These are the only issues that are relevant during the sanity trial.
If the jury decides unanimously that the defendant was insane when s/he committed the crime, then s/he will be found not guilty by reason of insanity.
The sanity hearing usually takes place before a jury—but not always. A judge may remove the issue of insanity from the jury if s/he feels that the defendant has failed to present sufficient evidence that they were insane when they committed the crime.
3.3. Entering a single plea of “not guilty by reason of insanity”
In some cases, a defendant and his/her attorney may decide that it makes the most sense not to bother with a standard “not guilty” plea. Instead, the defendant concedes that s/he is guilty of the offense and only pleads the insanity defense.
In these cases, the court proceeds directly to the sanity trial described in Section 3.2. There is no separate trial on guilt or innocence.
California's "Insanity Defense" - The McNaghten Rule
See more at the link for examples of the accused's defense, sentencing, and more.
