There's a demurrer that I've filed a couple of times in the last 15 years (and other attorneys have also filed a few times) that has NEVER lost. How often does a defense attorney get to say that? It's true, though, but only because every prosecutor who has read the demurrer conceded well before a judge had a chance to rule on it. Alas, it applies to a charge that isn't charged very often. Here's the argument, which I just cut and pasted from the demurrer:
The statute that provides the basis for Count 109, ORS 166.450, violates the Constitutional guarantee that the state will be required to prove all elements of a crime beyond a reasonable doubt. State v. Rainey, 298 Or 459, 465, 693 P2d 635 (1985). The right not to be convicted of a crime except on proof of guilt beyond a reasonable doubt is also statutorily protected in Oregon. ORS 136.415. The statute in question reads in full: 166.450 Obliteration or change of identification number on firearms. Any person who intentionally alters, removes or obliterates the identification number of any firearm for an unlawful purpose, shall be punished upon conviction by imprisonment in the custody of the Department of Corrections for not more than five years. Possession of any such firearm is presumptive evidence that the possessor has altered, removed or obliterated the identification number. [Emphasis added.] As the Oregon Supreme Court has noted in State v. Rainey, 298 Or 459 (1985): The reasonable doubt standard requires that the prosecution prove each element of the crime beyond a reasonable doubt. In order to do so, the prosecution may not rely on a rebuttable presumption, because a presumption places the burden of persuasion on the criminal defendant in a manner inconsistent with the presumption of innocence and proof of guilt beyond a reasonable doubt. See State v. Stilling, supra ; see also Sandstrom v. Montana, 442 U.S. 510, 99 S Ct 2450, 61 L Ed 2d 39 (1979). Rainey at 465. [Emphasis added.] The statute self-evidently violates the statutory and constitutional guarantees described in Rainey. The defendant reserves further argument in the unlikely event that the prosecutor argues to the contrary.
And, as I mentioned, no prosecutor -- as far as I know -- has ever argued to the contrary.