Conviction for assault with a deadly weapon reversed where the instructions permitted the jury to convict on the legally invalid theory that a box cutter was an inherently deadly weapon. The defendant thrust the exposed blade of a box cutter toward a man while threatening to kill him. The jury convicted him of assault with a deadly weapon and making criminal threats, and found true an allegation that he personally used a deadly and dangerous weapon. The jury instructions defined “a deadly weapon” as “any object, instrument, or weapon that is inherently deadly or one that is used in such a way that it is capable of causing or likely to cause death or great bodily injury.” During closing arguments, the prosecutor told the jury that a box cutter was “an inherently deadly weapon.” On appeal, Aledamat argued that the trial court erred in instructing the jury that it could find a box cutter to be an “inherently deadly” weapon. Held: Assault with a deadly weapon conviction and deadly weapon enhancement reversed. A “deadly weapon” is “inherently deadly” when it is dangerous or deadly to others in the ordinary use for which it is designed. A box cutter is a type of knife, and is not an inherently deadly weapon because it is designed to cut things, not people. Here, the Court of Appeal accepted the People’s concession that the “inherently deadly” weapon portion of the jury instruction was inapplicable in this case where the weapon was a box cutter. The court also concluded that the erroneous jury instruction entailed the presentation of a legally (rather than factually) invalid theory. As a result, the assault conviction and personal use enhancement had to be reversed because there was no basis in the record for concluding that that the jury relied on the legally valid definition of “deadly weapon.” [Editor’s Note: The Court of Appeal noted that the prejudice rules it applied in this case are arguably in tension with more recent cases, such as People v. Merritt (2017) 2 Cal.5th 819. But the case law the court applied here was directly on point and binding, and it would be up to Supreme Court to reconsider the case law.]