dissenting.
I would reverse and remand. Because of the improper amendment of the indictment, the remand would be for a finding of probable cause on the new charge.
Improper Amendment of the Indictment: An inmate found a .45-gram baggie of cocaine in Appellant’s car. The indictment read: “On or about January 15, 1992, Greg Manuel Olea did knowingly possess or use a narcotic drug, to wit: .45 grams of cocaine ____” In response to a pre-trial motion from Appellant, the State elected to proceed on a theory of “use.” There was no discussion about the .45 grams. As later became apparent, the State assumed that the reference to .45 grams was stricken from the indictment, and Appellant assumed it was still there.
When the trial court raised the issue during jury selection, the State moved to strike the reference to the .45 grams, making explicit for the first time its intention to try Appellant for use of whatever cocaine produced the positive urinalysis. (An explanation for this tactic is found in final argument, when the prosecutor told the jury that if the only evidence was the baggie, “perhaps you could acquit the defendant for possession. Perhaps that case would not have ever been filed because it is real hard to prove who had access to that vehicle.”)
Everyone agrees that the grand jury indicted Appellant for possession or use of the .45-gram baggie. The trial court saw that the proposed day-of-trial amendment was material, not technical, and decided not to let the State do it. But the court eventually allowed the amendment. Appellant made-timely objection to the process by which the grand jury’s indictment for possession or use of a .45-gram baggie of cocaine developed into a trial on the prosecutor’s accusation that Appellant had used whatever cocaine produced a positive urinalysis. Appellant was entitled to a timely and formal accusation of the new charge, and to a probable cause determination regarding it. That he received neither of these formalities was a fundamental defect that violated due process and Rule 13.5(b), Arizona Rules of Criminal Procedure (“The ... indictment limits the *494trial to the specific charge or charges stated in the ... indictment.”).
That both the old and the new charge involved the same kind of drug should not obscure the fact that Appellant was indicted on one specific charge (possession or use of the .45-gram baggie of cocaine found in his car), then tried over his objection on a completely different specific charge (use of whatever cocaine produced the positive urinalysis). The amendment should not have been allowed over objection.
The State’s right to amend an indictment “to conform to the evidence is subject to limitations to protect a defendant’s constitutional rights.” State v. Delgado, 174 Ariz. 252, 255, 848 P.2d 337, 340 (App.1993). An indictment represents the findings of a grand jury, and the trial court may not amend it to charge new and different substantive matters without the concurrence of the grand jury. See State v. Fogel, 16 Ariz.App. 246, 250, 492 P.2d 742, 746 (1972) (citations omitted); see also State v. Rybolt, 133 Ariz. 276, 280, 650 P.2d 1258, 1262 (App.1982), overruled on other grounds by State v. Diaz, 142 Ariz. 119, 120, 688 P.2d 1011, 1012 (1984) (citations omitted).
Erroneous Jury Instruction: Appellant’s urine sample contained 189 nanograms of cocaine metabolite per milliliter. A nanogram is one billionth of a gram. The State’s expert testified that a reading above 150 nanograms is regarded in the drug-testing industry as positive for cocaine, but that is all the reading means—it says nothing about how much cocaine was ingested, or when. The State produced no evidence that the metabolite in Appellant’s urine was the byproduct of a usable amount of cocaine. None of the State’s experts was asked whether it takes a usable amount of cocaine to produce a positive urinalysis.
The crime of possession of a drug requires proof that the defendant knowingly possessed a usable amount of the drug. State v. Murphy, 117 Ariz. 57, 62, 570 P.2d 1070, 1075 (1977); State v. Payan, 15 Ariz.App. 128, 129, 486 P.2d 808, 809 (1971) (citing State v. Moreno, 92 Ariz. 116, 120, 374 P.2d 872, 875 (1962)). The court advised counsel that it would include a usable amount element in the jury instructions. The court also proposed to give the standard definition that, “an amount is usable if it is of such quality and quantity that it can be used according to the practices of narcotics users.” See RAJI (Criminal) § 34.081 (1989); cf. State v. Quinones, 105 Ariz. 380, 382 n. 3, 465 P.2d 360, 362 n. 3 (1970) (amount of drug usable if of quality and quantity that it can be used as a narcotic).
But the State argued, and the trial court eventually agreed, that one could not use less than a usable amount, and it would therefore be redundant to include a usable amount element and definition in the instructions. This argument is appealing, but circular. To say, “He used it, therefore it was a usable amount,” is to begin and end with the conclusion that only a usable amount of cocaine produces a positive urinalysis. Perhaps this conclusion is valid, but we have no basis for taking judicial notice of it, and there was nothing presented in this trial to prove it. The State offered no evidence to associate 189 nanograms of metabolite with a usable amount of cocaine, the trial court offered no instruction on usable amount, and the Appellant made sufficient objection to both of these omissions.
Respectfully, I think we err in concluding that the crime of use is more absolute than the crime of possession. The relevant statute is A.R.S. section 13-3408(A)(1), which provides: “A person shall not knowingly: 1. Possess or use a narcotic drug.” There is no reason to construe this simple statute to require a usable amount of cocaine for possession, but not for use.
If the legislature intended metabolite to be enough for a use conviction, it would likely have used in the drug code the same language it used in the motor vehicle code. A.R.S. section 28-692(A)(3) makes it unlawful—a misdemeanor—to drive a vehicle “while there is any drug ... or its metabolite in the person’s body.” The absence of meta*495bolite language in the statute that makes it a felony to knowingly possess or use cocaine is another reason why, in a prosecution for use of cocaine, the State has to prove more than metabolite in the person’s body; it has to prove that the person knowingly used a usable amount of cocaine. The usable amount element might be easy to prove, but it is as essential in a use case as in a possession case.