It would be reassuring to think that George Zimmerman’s acquittal on murder charges in the death of Trayvon Martin finally settled the matter, that we could take the acquittal as the jury’s conclusion that the shooting was reasonable self-defense. Unfortunately, a serious flaw in Florida law leaves that conclusion uncertain.

The acquittal might mean one of two things: that Zimmerman acted entirely reasonably, or that he acted unreasonably, yet was less blameworthy than a stone-cold murderer. If the latter, then a federal inquiry might be justified.

The states are split on how they formulate their self-defense statutes. The Model Penal Code of the American Law Institute, the basis for three-quarters of the states’ codes, provides a “sliding scale” of liability. If someone acts in reasonable self-defense, that person gets a complete acquittal. Yet if he makes an honest but unreasonable mistake -- sometimes called “imperfect self-defense” -- then he has some liability, something short of murder liability, usually negligent or reckless homicide.

In many states, however, including Florida, statutes reject this approach in favor of “all or nothing.” If the person is perfectly reasonable in judging the need to shoot in self-defense, he gets an acquittal. If his self-defense is performed imperfectly, however, then there is no defense or mitigation: The accused is treated the same as the cold-blooded killer who had no thought of self-defense.

Juries Balk

Juries often see this as an unjust result, and sometimes balk at it. A person who makes a mistake in the chaos of defending himself in an attack is seen as much less culpable than a person who intentionally kills when there is no call for self-defense.

It was this all-or-nothing approach that probably led a New York jury to acquit the “subway vigilante,” Bernhard Goetz, in 1987. Even after his first round of shots scattered the four young men whom he said were planning to rob him, he approached one of them, Darrell Cabey, who was sprawled on a seat near the conductor’s cab and said: “You don’t look so bad. Here’s another.” He then shot again, severing Cabey’s spinal cord. Goetz might have honestly believed he had to shoot Cabey to protect himself from death, though it was hard to see how this could have been judged a reasonable belief.

And if it wasn’t a reasonable belief, then New York’s all-or-nothing statute would treat Goetz the same as if he shot Cabey just to shoot him -- without any claim of self-defense. The jury refused to do this, and instead gave Goetz the only other option available: not guilty on all assault charges.

The Zimmerman case might have presented a similar dilemma for the jurors. They might have found his belief that he, like Goetz, needed to shoot in self-defense to be honest if unreasonable. The jury might have thought Zimmerman deserved some criminal liability but not that of a murderer. Unfortunately, the Florida all-or-nothing self-defense statute, like New York’s, permits only complete acquittal or murder.

The Florida authorities haven’t been ignorant of the problem created by the statute. The prosecutor and judge tried to override the legislature’s all-or-nothing approach by fabricating an intermediate path -- the last-minute manslaughter option. Setting aside whether it is proper for the judiciary to rewrite the legislature’s statute, the court simply didn’t have the legal tools needed to do it.

In Florida law, the manslaughter offense is meant to cover primarily cases where a person creates only a risk of serious injury or death -- as when you start a dangerous fire in your backyard that accidentally burns down your neighbor’s house with him in it. This wasn’t the case with Zimmerman, who fully intended to shoot Martin, at close range. The offense has nothing to do with imperfect self-defense.

Confusing Instructions

So it was no surprise that its inclusion in the jurors’ instructions only served to confuse them. A day into their deliberations, the jury sent the judge a note asking for “clarification on the instructions regarding manslaughter.”

The judge replied that she couldn’t engage in “general discussions” on the charge, only answer specific questions from the jury. It never submitted any.

Many all-or-nothing states refuse to allow such attempts to jury-rig an intermediate verdict. They know that some juries might be tempted to use this option even if it violates the directive that self-defense be all or nothing.

Part of the tragedy in the Zimmerman case is that we can’t know what the jurors really thought about his conduct (we will only know what they now say they believed).

Did they acquit because they found Zimmerman acted in completely reasonable self-defense? Or did they think he committed culpable errors, but didn’t believe he was a stone-cold killer, no matter what the self-defense statute directed?

Florida and other all-or-nothing states should fix their statutes, not by trying to fabricate intermediate verdicts, but by expressly providing the intermediate imperfect self-defense option that the Model Penal Code urges.

(Paul H. Robinson is a law professor at the University of Pennsylvania and the author most recently of “Intuitions of Justice and the Utility of Desert.”)

To contact the writer of this article: Paul H. Robinson at phr@law.upenn.edu.

To contact the editor responsible for this article: Katy Roberts at kroberts29@bloomberg.net.