I have previously made the observation that ambiguity favors the state. It's not just because -- given two interpretations of the law that are in equipoise -- judges will consistently rule in a manner favoring the state. Rather, it's because you and the defendant have to assume the worst-case scenario (i.e, the most state-favorable interpretation of the law) in your calculations, while the prosecutor does not have to do the opposite. This significantly impacts negotiating leverage.
So, an old example. A defendant threatens his girlfriend with a knife, but he doesn't hurt her in any way. Says he will but he doesn't. He is charged with Unlawful Use of a Weapon and Menacing. I have argued that even in light of recent case law, the defendant's behavior does not constitute use of a weapon if he only intended to threaten her.
If I'm right, the judge may not agree. The jury may not buy my argument. There is still the possibility my client will get a felony conviction, on top of the misdemeanor conviction. If we go to trial, it's ten years before my client can expunge either conviction, and jail is more likely.
The prosecutor, on the other hand, has no incentive to concede the issue, because either a concession or an acquittal would both mean a result no worse than a menacing conviction. And the prosecutor sees the law differently than I do anyway, and she knows the default position of the judge and jury is more likely to align with her reading of the law, so really, zero reason to concede. If the prosecutor offers a felony plea, with no jail and no additional misdemeanor, the vast majority of defense attorneys will encourage their clients to take it.
The other problem is that a motion for judgment of acquittal is a horrible way to clear up the ambiguity. Because even if I'm right that a mere threat isn't UUW, the evidence -- in the light most favorable to the state -- could suggest that my client possessed the knife and intended to stab her with it, but changed his mind before doing so. In that situation, the charge survives the MJOA, and the COA won't disturb that ruling, even though my interpretation of the law -- and not the prosecutor's -- is the right one.
This is why a special jury instruction for UUW is so important, for the reasons I discuss at this post.
Take another example. Cop tries to pull over a defendant for a traffic infraction. Instead of pulling over, the defendant drives at the speed limit, using all turn signals, another half-mile to his house. He parks in the driveway. He is now charged with Felony Attempt to Elude.
The prosecutor says he's guilty, because failing to pull over immediately was enough to make him guilty. But you say, no, he wasn't fleeing. He wasn't trying to get away from the officer. He just didn't yield, which is just a violation.
So, at best, the law is ambiguous. You can argue over your different interpretations of the law to the jury, but it's a crapshoot who they'll believe.
The solution is to ask for a special jury instruction that says something like, "Merely failing to yield to the police car does not constitute felony fleeing. To be guilty, the defendant must also intend to get away from or 'lose' the police car."
If you get that instruction, you win most of the time. If the judge denies that instruction (and you properly except at the right time), you have a very well preserved issue for appeal.
But defense lawyers are taught to always ask for a motion for judgment of acquittal, and rarely told that they should always be asking for special jury instructions. This is why these ambiguities in the law can survive decades without any clarity from the Court of Appeals.
So, my rule of thumb is this: if you and the prosecutor interpret the elements of a crime differently, and guilt or innocence depends on whose interpretation is relied upon, then you need to ask for a special jury instruction.