Penal Code section 12022 is a sentence enhancement provision, which states in subdivision (a)(1); “[A]ny person who is armed with a firearm in the commission of a felony or attempted felony shall be punished by an additional and consecutive term of imprisonment . . . .”1 (Italics added.) In People v. Bland (1995) 10 Cal.4th 991 [43 Cal.Rptr.2d 77, 898 P.2d 391] (Bland), this court construed the italicized statutory phrase this way; The arming must occur “during the commission of the underlying felony” (id. at p. 1001) and there must be some “nexus or link” between the firearm and that crime (id. at p. 1002).
In this case, police found methamphetamine and a firearm in defendant’s van. The prosecution charged him with the felonies of possessing and transporting the drug, and it alleged an arming enhancement with respect to both crimes. Defendant denied any relationship between the methamphetamine and the firearm, claiming he had the latter because he was contemplating suicide. The trial court failed to instruct on Bland’s requirement there that be a nexus or link between the firearm and the underlying drug crime. Therefore, in finding the arming enhancement allegations to be true, the jury was precluded from considering the defense argument that the gun had no connection to the methamphetamine.
Contrary to the Court of Appeal, which set aside the enhancements, the majority here upholds the trial court’s failure to instruct, on its own initiative, on the nexus or link aspect of the Bland test. I disagree. The Court of Appeal got it right, and I would affirm the judgment of that court.
I
As relevant here, defendant was charged with the felonies of possessing methamphetamine for sale (Health & Saf. Code, § 11378) and transporting it (id., § 11379, subd. (a)), and it was alleged that “in the commission” of those offenses defendant was personally “armed with a firearm” (Pen. Code, § 12022, subd. (c)).2
At trial, the prosecution presented this evidence: Northern California’s Lake County has a Narcotics Task Force consisting of law enforcement *242officers from various agencies, including the Lake County Sheriff’s Department and the City of Clearlake Police Department. In the early morning hours of May 23, 2003, task force members saw defendant drive a van into the parking lot of the Twin Pines Casino, located in Middletown, Lake County. The casino parking lot was known to task force members as a “hot spot” for methamphetamine dealing. When defendant got out of his van with a dog on a leash, task force members stopped him and, knowing him to be on probation and thus subject to warrantless search, they entered the van. On the floor in the back of the van was a plastic garbage bag filled with clothing and other personal items. Protruding from a cigarette package in the garbage bag was a clear plastic baggie containing a substance later determined to be 12.09 grams of crystal methamphetamine. About a foot away from the garbage bag, behind the driver’s seat, was a cardboard box containing, among other things, a zippered pouch. Inside the pouch was an unloaded .357 Ruger revolver; in a separate compartment of the pouch were six rounds of ammunition.
The defense presented this evidence: Defendant was on his way from Contra Costa County to his family’s Lake County vacation house, where he planned to spend the May 2003 Memorial Day weekend, when he stopped at the casino parking lot so his dog could relieve itself. To counter the prosecution’s drug charges, defendant, his brother, and his mother testified to defendant’s longtime methamphetamine addiction, explaining that he possessed the 12.09 grams of methamphetamine in the plastic baggie not for the purpose of sale but for his personal use.
And to counter the prosecution’s theory that defendant was armed with a firearm “in the commission” of the two drug felonies, the defense presented testimony from defendant’s brother and mother that defendant disliked firearms, that he had recently been depressed, and that he talked about killing himself. Defendant testified that he had considered committing suicide, but that he had no immediate plan to do so when he drove into the casino parking lot where task force members encountered him. He explained that the revolver and six rounds of ammunition found in his van were for this purpose.
The trial court’s instruction to the jury on section 12022’s arming enhancement was based on the standard jury instruction, CALJIC No. 17.15.3 In closing argument, the prosecutor drew the jury’s attention to that instruction. *243Under that instruction, the prosecutor said, defendant’s reason for having the gun was not an issue, and the jury need only decide whether the gun was “available for [defendant] to use if he chose to do so.”
During deliberations, the jury sent a note to the trial court asking for the “[definition of Penal Code section 12022 with the [.sic] regards to the term ‘armed.’ ” When the trial court called the jury back into the courtroom to respond to the question, one juror said: “I think the question was availability, what constitutes availability?” The court replied: “That would be a question for you to decide. It’s a question of fact as to whether or not this shows that firearm was available for offensive or defensive use. That would be within your purview alone, so I couldn’t answer that question for you.”
The jury acquitted defendant of the charge of possessing methamphetamine for sale, but it convicted him of the lesser included felony offense of unauthorized possession of methamphetamine (Health & Saf. Code, § 11377), and it also convicted him of transporting methamphetamine. With respect to both felonies, the jury found that defendant was “armed with a firearm in the commission” of the offense.4 The trial court sentenced defendant to a state prison term that included four years for the section 12022 arming enhancements. Defendant appealed.
Relying on Bland, supra, 10 Cal.4th 991, the Court of Appeal concluded that the trial court’s instruction on the section 12022 arming enhancement was defective in omitting the requirement of a nexus or link between the firearm found in the van and defendant’s illegal possession and transportation of the methamphetamine. Determining the omission to be prejudicial to defendant, the Court of Appeal struck the jury’s findings on the enhancements. The Attorney General asked this court to depublish the Court of Appeal’s decision. We granted review on our own initiative.
II
Central to defendant’s claim of instructional error is this court’s 1995 decision in Bland, supra, 10 Cal.4th 991, which is summarized below.
*244In Bland, the defendant was in a police car outside his house when police searched the house and found in the defendant’s bedroom closet 17.95 grams of rock cocaine; nearby was a duffel bag containing a gram scale, plastic baggies, and other items typically associated with the manufacture and sale of cocaine base. Also in the bedroom were several unloaded firearms, including a Colt AR-15 semiautomatic assault rifle and a photograph of the defendant with the assault rifle. (Bland, supra, 10 Cal.4th at p. 995.)
The jury in Bland found the defendant guilty of two felony counts of possession of cocaine base for sale (Health & Saf. Code, § 11351.5), and as to one of those counts found that he was armed with an assault weapon in the commission of that offense (Pen. Code, § 12022, subd. (a)(2)). The Court of Appeal set aside the section 12022 arming enhancement for insufficient evidence. It reasoned that the defendant could not have been armed with the assault weapon in committing the felony at issue because the unloaded assault rifle retrieved by the officers was not accessible to the defendant, who was outside the house during the police search. This court disagreed. It reasoned that evidence of the defendant’s possession of drugs and drug paraphernalia near the assault rifle was sufficient to establish that he was armed in the commission of the felony drug possession, within the meaning of section 12022. (Bland, supra, 10 Cal.4th at pp. 995-997.)
In construing section 12022’s phrase, “armed with a firearm,” Bland explained that a defendant need not “utilize a firearm or even carry one on the body.” (Bland, supra, 10 Cal.4th at p. 997.) Rather, “[a] defendant is armed if the defendant has the specified weapon available for use, either offensively or defensively.” (Ibid.)
Next, Bland discussed the nature of drug possession, describing it as a “ ‘continuing’ offense,” that is, one that “extends through time.” (Bland, supra, 10 Cal.4th at p. 999.) “Thus, throughout the entire time the defendant asserts dominion and control over illegal drugs, the defendant is criminally liable for the drug possession.” (Ibid.)
Bland held that, for purposes of section 12022’s arming enhancement, a defendant could be armed in the commission of a possessory drug offense even though not near the firearm and the drugs when arrested. The important circumstance, Bland said, was whether the defendant “had the firearm available for use in furtherance of the drug offense at any time during his possession of the drugs.” (Bland, supra, 10 Cal.4th at p. 1000, italics added.)
Of particular relevance here is this observation in Bland: “Of course, contemporaneous possession of illegal drugs and a firearm will satisfy the statutory requirement of being ‘armed with a firearm in the commission’ of *245felony drug possession only if the evidence shows a nexus or link between the firearm and the drugs. The federal courts, in interpreting the federal counterpart to California’s weapons enhancement law (18 U.S.C. § 924(c)(1)), have described this link as a ‘facilitative nexus’ between the drugs and the gun. (See United States v. Paulino (1st Cir. 1994) 13 F.3d 20, 26.) Under federal law, which imposes specified prison terms for using or carrying a firearm ‘ “during and in relation to” ’ a crime of drug trafficking, ‘the firearm must have some purpose or effect with respect to the drug trafficking crime; its presence or involvement cannot be the result of accident or coincidence.'’ (Smith v. United States (1993) 508 U.S. 223, 238 [124 L.Ed.2d 138, 113 S.Ct. 2050], italics added.)” (Bland, supra, 10 Cal.4th at p. 1002, first and second italics added.)
Section 12022’s arming enhancement, Bland observed, “implicitly requires” a similar “ ‘facilitative nexus’ ” in light of the statute’s requirement that the arming occur “in the commission” of the charged felony. (Bland, supra, 10 Cal.4th at p. 1002.) Thus, the arming under section 12022 must occur “during the commission of the underlying felony” (Bland, supra, at p. 1001) and it must have “some facilitative nexus’ to that offense” (id. at p. 1002). Bland went on to hold: “[From evidence] that a firearm was found in close proximity to . . . illegal drugs in a place frequented by the defendant, a jury may reasonably infer (1) that the defendant knew of the firearm’s presence, (2) that its presence together with the drugs was not accidental or coincidental, and (3) that, at some point during the period of illegal drug possession, the defendant was present with both the drugs and the firearm and thus that the firearm was available for the defendant to put to immediate use to aid in the drug possession.” (Id. at pp. 1002-1003.) Bland cautioned, however, that these reasonable inferences could support a jury determination that the defendant was armed with a firearm “in the commission” of the charged felony so long as the inferences were “not refuted by defense evidence.” (Id. at p. 1003, italics added.)
Relying on this statement in Bland, the Court of Appeal here set aside the jury’s findings on the section 12022 arming enhancements. The court pointed to the defense evidence that defendant had the gun in his van not to aid in the felonies of possessing and transporting methamphetamine but because he was contemplating suicide. In light of that evidence, the Court of Appeal concluded, the trial court had a sua sponte obligation to instruct the jury that for defendant to be armed with a firearm in the commission of a felony, there had to be some “facilitative nexus” between the firearm and the felony. I agree. Below, I explain why.
*246III
Section 12022’s subdivision (a)(1) states: “[A]ny person who is armed with a firearm in the commission of a felony or attempted felony shall be punished by an additional and consecutive term of imprisonment. . . .” (Italics added.) As discussed in part II, ante, this court’s decision in Bland construed the phrase “armed ... in the commission” of a felony offense as meaning that the arming must occur “during the commission of the underlying felony” (Bland, supra, 10 Cal.4th at p. 1001) and must have some link or nexus to that offense (id. at p. 1002). A jury may reasonably infer from a firearm’s close proximity to illegal drugs that the firearm’s “presence together with the drugs was not accidental or coincidental.” (Bland, supra, at p. 1003.) But this inference can be “refuted by defense evidence” to the contrary. (Ibid.) That is what occurred in this case.
Defendant presented evidence that he had the .357 Ruger revolver in his van because he had been contemplating suicide, which supported the theory that the gun’s presence was unrelated to his possession and transportation of methamphetamine. The trial court’s instruction to the jury, however, precluded consideration of this theory.
In the language of CALJIC No. 17.15, the trial court instructed the jury that if it found defendant guilty of either one of the two felonies, it must then decide whether defendant “was armed with a firearm at the time of the commission or attempted commission” of that felony. (CALJIC No. 17.15, italics added; see p. 242, fn. 3, ante.) Thus, this instruction properly included the temporal requirement set forth in Bland, supra, 10 Cal.4th 991, that the arming must take place during the underlying felony. But the jury was not instructed on Bland's additional requirement that to be armed in the commission of a felony, the arming must have some link or nexus to that felony. A trial court must, on its own initiative, instruct the jury on those general legal principles that are relevant to the defense theory of the case and supported by the evidence. (People v. San Nicolas (2004) 34 Cal.4th 614, 669 [21 Cal.Rptr.3d 612, 101 P.3d 509]; People v. Breverman (1998) 19 Cal.4th 142, 157 [77 Cal.Rptr.2d 870, 960 P.2d 1094].)
In giving the jury an incomplete description of the “in the commission” element of section 12022’s arming enhancement, the trial court erred. This instructional error is harmless only if beyond a reasonable doubt it did not affect the jury’s verdict. (People v. Sengpadychith (2001) 26 Cal.4th 316, 324-326 [109 Cal.Rptr.2d 851, 27 P.3d 739]; see also Neder v. United States (1999) 527 U.S. 1, 10 [144 L.Ed.2d 35, 119 S.Ct. 1827] [with both “misdescriptions and omissions—the erroneous instruction precludes the jury from making a finding on the actual element”]; California v. Roy (1996) 519 U.S. 2, 5 [136 L.Ed.2d 266, 117 S.Ct. 337].)
*247Here, the instructional error precluded the jury from considering defendant’s claim that the gun’s presence in the van had no connection to the nearby methamphetamine that was concealed in a cigarette package inside a plastic garbage bag together with defendant’s clothing and other personal items. Whether a majority of this court disbelieves the defense evidence that defendant had the gun to commit suicide is beside the point. It was for the jury, as the trier of fact, to consider that defense evidence, and to either accept or reject it.
Compounding the instructional error was the prosecutor’s erroneous comment in closing argument to the jury that defendant’s reason for having the gun in the van was irrelevant; the pertinent issue for the jury, the prosecutor said, was whether the gun was “available” to defendant. The jury’s apparent confusion on this very point is evident from its inquiry of the trial court on the meanings of the terms “armed” and “availability” for purposes of the section 12022 arming enhancement. The trial court provided no answers. (See dis. opn., ante, at pp. 242-243.)
Under these circumstances, I cannot conclude that beyond a reasonable doubt the instructional error had no effect on the jury’s verdict, and I would affirm the Court of Appeal in setting aside the arming enhancement.
IV
The majority insists that in this case there was no need to instruct the jury on the necessity of finding a link or nexus between the gun and the nearby drugs in defendant’s van. It reasons that defendant did not sufficiently refute the inference of arming arising from the prosecution’s case because he admitted knowing that the pistol was in the van near the methamphetamine when he testified to deliberately placing the gun and the drugs in his van. (Maj. opn., ante, at p. 238.) According to the majority, the “close proximity [of the drugs and the gun] did not occur through ignorance or happenstance.” (Ibid.)
I disagree with the majority that a defendant who knows that a firearm is near illegal drugs in his possession can never refute an inference of being armed within the meaning of section 12022. The majority acknowledges that this court’s decision in Bland established a purpose and effect test. (Maj. opn., ante, at p. 239.) As Bland put it, “ ‘the firearm must have some purpose or effect with respect to the drug trafficking crime; its presence or involvement cannot be the result of accident or coincidence.’ ” (Bland, supra, 10 Cal.4th at p. 1002, first italics added.) As the majority sees it, a firearm found near illegal drugs always meets the Bland test so long as the defendant knows of the gun’s presence and can retrieve it to further any unlawful purposes in connection with the drugs. I do not share that view.
*248When a defendant has knowingly placed a firearm nearby illegal drugs, the gun’s mere presence cannot, under Bland, supra, 10 Cal.4th 991, be considered an “ ‘accident.’ ” (Id. at p. 1002, italics omitted.) But the location of the gun near the drugs may well be a “ ‘coincidence.’ ” (Ibid., italics omitted.) As discussed earlier, that was the essence of the defense here. The jury, as trier of fact, may not have accepted that defense, but defendant was entitled to have the jury at least consider it. The jury was precluded from doing so, however, because of the trial court’s failure to instruct on the necessity of finding a link or nexus between the gun and the underlying felonies of possessing and transporting methamphetamine.
I would affirm the Court of Appeal.
Further undesignated statutory references are to the Penal Code.
Section 12022, subdivision (c) provides for additional terms of imprisonment of three, four, or five years for certain, specified drug-related felonies. The increased prison term under section 12022, subdivision (a)(1), the basic arming enhancement provision, is one year.
The jury instruction read: “It is alleged in Counts 1, 2, and the violation of Health & Safety Code § 11377(a) which is a lesser crime to Count 2 that in the commission of the felony therein described, a principal was armed with a firearm, namely a .357 Ruger pistol. ['][] If you find a defendant guilty of the crimes thus charged, you must determine whether a principal in that crime was armed with a firearm at the time of the commission or attempted commission of the crimes. fl[] A principal in the commission of a felony is one who either directly and actively commits or attempts to commit the crime or one who aids and abets the commission *243or attempted commission of the crime, [f] The term ‘armed with a firearm’ means knowingly to carry a firearm or have it available for offensive or defensive use. [f] The word ‘firearm’ includes a pistol, revolver, shotgun, or rifle. [][] The People have the burden of proving the truth of this allegation. If you have a reasonable doubt that it is true, you must find it to be not true.” (Italics added.)
With respect to the conviction for possessing methamphetamine under Health and Safety Code section 11377, the arming enhancement was governed by Penal Code section 12022, subdivision (a)(1) (setting out a one-year enhancement) and not its subdivision (c) (setting out additional terms of imprisonment of three, four, or five years for arming in the commission of specified drug offenses), because simple possession is not one of the offenses covered by section 12022, subdivision (c).