Is the “Low Sodium Defense” The New Twinkie Defense?

No. And, come to think of it, the “Twinkie Defense” isn’t really a real thing, either (more on that later).

Anyway, a man in Michigan is currently facing trial for the murder of his own mother. His lawyer has told the media that he plans to claim that a sodium imbalance caused him to become delusional, and that he should be found not guilty by reason of temporary insanity (also reported here).

I predict that this case is going to lead to a lot of outcry about our “broken justice system,” with pundits decrying how easy it is to squirm away from justice with an insanity defense. This makes for good television. Between the 24-hour news cycle and indignation apparently becoming our national pastime, we’re always looking for new things to get mad about. However, perhaps we should find things that are actually worth getting mad about, because the insanity defense most definitely does not fit the bill.

For reasons that still aren’t clear to me, the insanity defense has gotten a really bad rap in recent decades. I’m really not sure why. After all, in our criminal justice system, most crimes have an element of intent: in order to convict a defendant, the prosecution must show that they acted with mens rea (“guilty mind”), in addition to proving that they actually engaged in the unlawful conduct they’re accused of. This mens rea typically takes the form of intent (i.e., in addition to showing that the defendant engaged in the unlawful conduct they’re accused of, it must be shown that they intended to engage in that conduct).

If a person’s mind is so warped that they are unable to act with any form of intent, or to understand the nature of their actions, and they’re able to prove this, they cannot, by definition, commit murder. This is because there is no intent to kill when they act. Such a person is obviously not as morally culpable for their actions, no matter how serious the harm is.

That’s not to say that you can’t take legal action against such people. If a person is found not guilty by reason of insanity, they are typically committed to a mental institution. This is not to punish them, but simply to protect society from any future violent conduct they might engage in. A person committed in this way can remain in the mental institution until they are deemed to no longer pose any threat to themselves or others. In some cases, this might never happen, which means that the patient can be institutionalized indefinitely, perhaps for a longer period than the prison sentence they would serve if convicted.

So, being found not guilty by reason of insanity is definitely not the ticket to freedom that some people seem to think it is. Furthermore, the insanity defense is successful in a tiny, tiny minority of cases. The insanity defense is only raised in less than 1% of all criminal trials in the United States. And, when the defense is employed, it’s only successful 25% of the time. This means that criminal defendants are found not guilty by reason of insanity in less than one quarter of one percent of all cases.  This is party because the insanity defense is extremely difficult to prove. As with all affirmative defenses, the burden of proving the facts necessary to establish an insanity defense rests entirely on the defendant.

An insanity defense requires far more than a simple showing that the defendant suffers from a mental illness. However, mental illness is a necessary (but not sufficient) element.

In order to succeed in an insanity defense, it must be shown that the defendant suffers from a “mental disease or defect” – basically a mental illness. It must further be shown that the mental illness is so severe that it either renders a person incapable of conforming their conduct to the law, or of understanding the nature and consequences of their actions. This is a very high hurdle.

However, it seems that, whenever there’s a case that involves an insanity defense, and has even slightly unusual facts, people jump on it, and wildly misconstrue the facts. In this case, I have no doubt that this man’s sodium imbalance will morph into “a low-sodium diet” once it’s been filtered through the blogosphere, and made its way into the ultimate den of anti-factualism: chain emails.

It’s not as if there isn’t precedent for this. Remember the “Twinkie Defense?” When John White killed San Francisco Supervisor Harvey Milk, and mayor George Moscone, he was convicted of manslaughter, rather than murder, on the basis of “diminished capacity” (similar, but not identical, to the insanity defense). And some of the evidence that supported this defense involved White’s consumption of junk food.

If you ask just about anyone about this case, they’ll probably tell you that Dan White got off because he claimed that eating a bunch of junk food made him go crazy. Of course, that’s not what happened at all. The defense pointed out that Dan White was something of a health nut, but a few months before the killing he began eating nothing but junk food, and neglected his health in other ways. This was simply one piece of evidence to show that he suffered from severe depression. But nobody ever claimed that it was a cause.

I have no doubt that, if this case gets some real media attention, the same thing will happen. I don’t know what causes such hostility to the insanity defense, but I really wish people would drop it.