Opinion
KENNARD, J.
Step by step, this court continues its struggle through the thicket of statutory construction issues presented by the California Street Terrorism Enforcement and Prevention Act of 1988, also known as the STEP Act. (Stats. 1988, ch. 1242, § 1, pp. 4127-4129; see People v. Robles (2000) 23 Cal.4th 1106 [99 Cal.Rptr.2d 120, 5 P.3d 176]; People v. Castenada (2000) 23 Cal.4th 743 [97 Cal.Rptr.2d 906, 3 P.3d 278]; People v. Zermeno (1999) 21 Cal.4th 927 [89 Cal.Rptr.2d 863, 986 P.2d 196]; People v. Loeun (1997) 17 Cal.4th 1 [69 Cal.Rptr.2d 776, 947 P.2d 1313]; People v. Gardeley (1996) 14 Cal.4th 605 [59 Cal.Rptr.2d 356, 927 P.2d 713].) Like Gardeley, this case involves Penal Code section 186.22, subdivision (b), a sentence enhancement provision for felonies committed “for the benefit of, at the direction of, or in association with any criminal street gang.”1 (Italics added.) The STEP Act defines a criminal street gang as “any ongoing organization, association, or group of three or more persons, whether formal or informal” that has as one of its “primary activities” the commission of one or more [320]*320statutorily enumerated criminal offenses and through its members engages in a “pattern of criminal gang activity.” (§ 186.22, subd. (f).) In Gardeley, we construed the phrase “pattern of criminal gang activity,” but we also touched on the gang statute’s “primary activities” requirement, an issue in this case.
The questions we decide here are these:
1. May the jury consider the circumstances of the charged crimes on the issue of the group’s primary activities? We hold that it can.
2. What standard of harmless error governs a trial court’s failure to instruct the jury on the requisite primary activities of the group? To answer this question, we look to the United States Supreme Court’s recent decision in Apprendi v. New Jersey (2000) 530 U.S. 466 [120 S.Ct. 2348, 147 L.Ed.2d 435] (Apprendi). That case holds as a matter of federal constitutional law: “Other than the fact of a prior conviction, any fact that increases the penalty for a crime beyond the prescribed statutory maximum must be submitted to a jury, and proved beyond a reasonable doubt.” (Id. at p. 490 [120 S.Ct. at pp. 2362-2363], italics added.) Applying Apprendi here, we conclude that, for felonies not punishable by an indeterminate term of imprisonment for life, the gang statute’s requirement of a finding by the trier of fact on the group’s primary activities is a “fact that increases the penalty” for the charged crime. Because such a finding is necessary to prove the criminal street gang enhancement, it is an element of the enhancement. Therefore, a trial court’s failure to instruct the jury on the necessity of such a finding is federal constitutional error. Such error must be evaluated under the high court’s test in Chapman v. California (1967) 386 U.S. 18 [87 S.Ct. 824, 17 L.Ed.2d 705, 24 A.L.R.3d 1065] (Chapman), which asks whether the prosecution has “prove[d] beyond a reasonable doubt that the error . . . did not contribute to” the jury’s verdict. (Id. at p. 24 [87 S.Ct. at p. 828].)
The gang enhancement provision does not, however, increase the maximum term of imprisonment for felonies punishable by life imprisonment: A defendant sentenced to life imprisonment for a gang-related crime is statutorily required to serve at least 15 years of that sentence before becoming eligible for parole. Because for this category of offenses the gang statute does not increase the maximum penalty for the crime, the failure to instruct on the primary activities requirement does not violate the federal Constitution. In that situation, therefore, Apprendi does not apply. Instead, it is a matter of state law error, subject to the test this court articulated in People v. Watson (1956) 46 Cal.2d 818, 836 [299 P.2d 243] (Watson), which asks [321]*321whether without the error it is “reasonably probable” the trier of fact would have reached a result more favorable to the defendant.2
I
The prosecution charged defendant with five counts of attempted willful, deliberate, and premeditated murder (§§ 187, subd. (a), 189, 664, subd. (a)), shooting at an inhabited dwelling house (§ 246), and shooting at an unoccupied motor vehicle (§ 247, subd. (b)). Each offense carried allegations of various sentence enhancements, including one for committing the offense to benefit a criminal street gang. (§ 186.22, subd. (b).)
At trial, the prosecution presented this evidence:
At 5:00 p.m. on May 9, 1996, Soeury “Eve” Pen was in the front yard of her home in San Jose with her friends Joel Dacanay, Pao Av, and Sal Vong, when defendant, who was her former boyfriend and a member of the Triple S gang, telephoned. Eve refused to talk to him. Dacanay, a member of Real Pinoy Brothers (RPB), Triple S’s main rival, returned the call and issued a gang challenge, in which Av and Vong joined.
Around 6:45 p.m., defendant and some companions drove to Eve’s house in a car and a truck. Standing outside were Av, Vong, and Dacanay. Also with them were Graylone Brown and Travis Cruz. Someone in the car yelled “Who’s RPB?” Dacanay answered he was. Defendant then got out of the truck with a handgun and started firing, hitting Cruz in the chest. Defendant also shot through a window and a wall of a nearby house, and he and a companion both shot through the rear window of a van parked on the street.
Detective Marty Hogan of the San Jose Police Department’s Violent Crime Unit, which investigates gang crimes, testified to a September 3, 1993, shooting committed by Triple S member Darius Augustin. That crime, like the shootings in this case, was in Detective Hogan’s opinion committed to benefit the Triple S gang.
The trial court instructed the jury on the criminal street gang sentence enhancement but failed to explain that, to trigger that provision, the jury had to find that one of Triple S’s primary activities was the commission of one or more statutorily enumerated felonies. (See § 186.22, subds. (e) & (f).)
[322]*322The jury convicted defendant of four counts of attempted murder and of shooting at an unoccupied motor vehicle. But it acquitted him of shooting at an inhabited dwelling house, finding him guilty of the lesser included offense of grossly negligent discharge of a firearm (§ 246.3). The jury also found true each of the criminal street gang and other sentence-enhancement allegations.
On one of the counts of attempted murder, the trial court sentenced defendant to an indeterminate term of imprisonment for life, consecutive to a determinate term of imprisonment. The court imposed concurrent sentences for defendant’s other offenses.
On defendant’s appeal, the Court of Appeal reversed and remanded for correction of certain sentencing errors. It also faulted the trial court for not instructing the jury on the gang enhancement’s primary activities requirement, but it found the error harmless under Watson, supra, 46 Cal.2d 818, 836. In support, the Court of Appeal cited this court’s decision in People v. Wims (1995) 10 Cal.4th 293 [41 Cal.Rptr.2d 241, 895 P.2d 77] (Wims).
After the Court of Appeal issued its decision, the United States Supreme Court decided Apprendi, supra, 530 U.S. 466. Defendant notified the Court of Appeal, asking it to grant rehearing on its own motion to reconsider the instructional issue, but the court lost jurisdiction without acting on that request.
We granted defendant’s petition for review.
II
To trigger the gang statute’s sentence-enhancement provision (§ 186.22, subd. (b)), the trier of fact must find that one of the alleged criminal street gang’s primary activities is the commission of one or more of certain crimes listed in the gang statute. In People v. Gardeley, supra, 14 Cal.4th 605 (Gardeley), that requirement was satisfied by the testimony of a police gang expert who expressed his opinion that the primary activities of the group in question were drug dealing and witness intimidation, both statutorily listed crimes. (See Gardeley, supra, 14 Cal.4th at pp. 611, 620.) Neither of these crimes was charged in Gardeley, they reflected past criminal cbnduct by members of the gang.
A year later, the Court of Appeal in In re Elodio O. (1997) 56 Cal.App.4th 1175, 1181 [66 Cal.Rptr.2d 95], read Gardeley as allowing only “past activity, not current offenses” as evidence of an alleged gang’s primary [323]*323activities. The next year, the Court of Appeal in People v. Galvan (1998) 68 Cal.App.4th 1135, 1140 [80 Cal.Rptr.2d 853], disagreed, holding that “either prior conduct or acts committed at the time of the charged offenses can be used to establish the ‘primary activities’ element of the gang enhancement.” As we explain, we agree with Galvan.
A
The STEP Act defines a criminal street gang as “any ongoing organization, association, or group of three or more persons, whether formal or informal, having as one of its primary activities the commission of one or more of \certain enumerated] criminal acts . . . , having a common name or common identifying sign or symbol, and whose members individually or collectively engage in or have engaged in a pattern of criminal gang activity.” (§ 186.22, subd. (f), italics added.) Nothing in this statutory language prohibits the trier of fact from considering the circumstances of the present or charged offense in deciding whether the group has as one of its. primary activities the commission of one or more of the statutorily listed crimes.
Evidence of past or present conduct by gang members involving the commission of one or more of the statutorily enumerated crimes is relevant in determining the group’s primary activities. Both past and present offenses have some tendency in reason to show the group’s primary activity (see Evid. Code, § 210) and therefore fall within the general rule of admissibility (id., § 351). Insofar as the Court of Appeal’s decision in In re Elodio O., supra, 56 Cal.App.4th 1175, allowed evidence only of past offenses, we disapprove it.
B
As we just discussed, evidence of either past or present criminal acts listed in subdivision (e) of section 186.22 is admissible to establish the statutorily required primary activities of the alleged criminal street gang. Would such evidence alone be sufficient to prove the group’s primary activities? Not necessarily. The phrase “primary activities,” as used in the gang statute, implies that the commission of one or more of the statutorily enumerated crimes is one of the group’s “chief’ or “principal” occupations. (See Webster’s Internat. Dict. (2d ed. 1942) p. 1963 [defining “primary”].) That definition would necessarily exclude the occasional commission of those crimes by the group’s members. As the Court of Appeal cautioned in People v. Gamez (1991) 235 Cal.App.3d 957, 970-971 [286 Cal.Rptr. 894], disapproved on another point in Gardeley, supra, 14 Cal.4th 605, 624, footnote 10: “Though members of the Los Angeles Police Department may commit [324]*324an enumerated offense while on duty, the commission of crime is not a primary activity of the department. Section 186.22 . . . requires that one of the primary activities of the group or association itself be the commission of [specified] crimefs]. . . . Similarly, environmental activists or any other group engaged in civil disobedience could not be considered a criminal street gang under the statutory definition unless one of the primary activities of the group was the commission of one of the [25] enumerated crimes found within the statute.”
Sufficient proof of the gang’s primary activities might consist of evidence that the group’s members consistently and repeatedly have committed criminal activity listed in the gang statute. Also sufficient might be expert testimony, as occurred in Gardeley, supra, 14 Cal.4th 605. There, a police gang expert testified that the gang of which defendant Gardeley had for nine years been a member was primarily engaged in the sale of narcotics and witness intimidation, both statutorily enumerated felonies. (See § 186.22, subd. (e)(4) & (8).) The gang expert based his opinion on conversations he had with Gardeley and fellow gang members, and on “his personal investigations of hundreds of crimes committed by gang members,” together with information from colleagues in his own-police department and other law enforcement agencies. (Gardeley, supra, at p. 620.)
Ill
What harmless error standard governs a trial court’s failure to instruct the jury on the primary activities element of the criminal street gang enhancement provision? Under the high court’s recent decision in Apprendi, supra, 530 U.S. 466, the answer depends on whether the enhancement provision increases the maximum possible penalty for the underlying crime.
The federal Constitution’s Fifth Amendment right to due process and Sixth Amendment right to jury trial, made applicable to the states through the Fourteenth Amendment, require the prosecution to prove to a jury beyond a reasonable doubt every element of a crime. (See Sullivan v. Louisiana (1993) 508 U.S. 275, 277-278 [113 S.Ct. 2078, 2080-2081, 124 L.Ed.2d 182].) Thus, a trial court’s failure to instruct on an element of a crime is federal constitutional error (see United States v. Gaudin (1995) 515 U.S. 506, 509-511, 522-523 [115 S.Ct. 2310, 2313-2314, 2319-2320, 132 L.Ed.2d 444]) that requires reversal of the conviction unless it can be shown “beyond a reasonable doubt” that the error did not contribute to the jury’s verdict (Chapman, supra, 368 U.S. at p. 24 [87 S.Ct. at p. 828]; People v. [325]*325Flood (1998) 18 Cal.4th 470, 492-504 [76 Cal.Rptr.2d 180, 957 P.2d 869]; see Neder v. United States (1999) 527 U.S. 1, 8-15 [119 S.Ct. 1827, 1833-1837, 144 L.Ed.2d 35]). Does the Chapman test also apply to the failure to instruct on a sentence enhancement? We explore this issue below.
This court held in Wims that under California statutory law the prosecution must prove beyond a reasonable doubt every element of a sentence enhancement, but that the federal Constitution does not impose such a requirement. (Wims, supra, 10 Cal.4th at pp. 298, 302-309, 314; but see id. at pp. 316-317 (conc. & dis. opn. of Mosk, J.); and id. at pp. 317-329 (conc. & dis. opn. of Kennard, J.).) Wims relied primarily on McMillan v. Pennsylvania (1986) 477 U.S. 79 [106 S.Ct. 2411, 91 L.Ed.2d 67] (McMillan), in which the high court considered a mandatory minimum sentencing law that required trial courts to impose a five-year minimum prison term on defendants who possessed a firearm in the commission of certain felonies; this five-year term did not, however, exceed the statutory maximum for any of the covered crimes. (Id. at pp. 81-82 [106 S.Ct. at pp. 2413-2414].) Noting that the Pennsylvania Legislature expressly intended firearm possession to be a “sentencing factor that comes into play only after the defendant has been found guilty of one of [the enumerated] crimes,” McMillan held that such sentencing factors need not be proved to a jury beyond a reasonable doubt. (Id. at pp. 80, 85-91 [106 S.Ct. at pp. 2413, 2414-2419].)
Because this court in Wims concluded that the California Legislature intended all statutory enhancements to be sentencing factors, it held that the failure to instruct the jury on an element of a sentence enhancement violated state law but not the federal Constitution. (Wims, supra, 10 Cal.4th at pp. 301, 306-307, 314.) Thus, Wims said, such error must be evaluated under this court’s test in Watson, supra, 46 Cal.2d at page 836, which asks whether without the error it is “reasonably probable” that a result more favorable to the defendant would have been obtained. (Wims, supra, at p. 315.)
Five years after this court’s 1995 decision in Wims, the United States Supreme Court held in Apprendi: “Other than the fact of a prior conviction, any fact that increases the penalty for a crime beyond the prescribed statutory maximum must be submitted to a jury, and proved beyond a reasonable doubt.” (Apprendi, supra, 530 U.S. at p. 490 [120 S.Ct. at pp. 2362-2363], italics added.) The high court’s reasoning was this: The federal Constitution requires the elements of a crime to be proved beyond a reasonable doubt because they expose the defendant to punishment', likewise, the elements of a sentence enhancement must be proved beyond a reasonable doubt if there is exposure to increased punishment. (Apprendi, supra, 530 U.S. at pp. 474-476, 482-484 [120 S.Ct. at pp. 2354-2356, 2358-2360]; see id. at [326]*326pp. 494-495 [120 S.Ct. at pp. 2365-2366.) The court treated a sentence enhancement as the functional equivalent of a crime. (Id. at pp. 476-477, 483, fn. 10 [120 S.Ct. at pp. 2355-2356, 2359].) To put it more accurately, Apprendi treated the crime together with its sentence enhancement as the “functional equivalent” of a single “greater” crime. (Id. at pp. 490-495 & fn. 19 [120 S.Ct. at pp. 2362-2365].)
This is what Apprendi teaches us: Except for sentence enhancement provisions that are based on a defendant’s prior conviction, the federal Constitution requires a jury to find, beyond a reasonable doubt, the existence of every element of a sentence enhancement that increases the penalty for a crime beyond the “prescribed statutory maximum” punishment for that crime. (Apprendi, supra, 530 U.S. at p. 490 [120 S.Ct. at p. 2363].) Therefore, a trial court’s failure to instruct the jury on an element of a sentence enhancement provision (other than one based on a prior conviction), is federal constitutional error if the provision “increases the penalty for [the underlying] crime beyond the prescribed statutory maximum.” (Ibid.) Such error is reversible under Chapman, supra, 386 U.S. at page 24 [87 S.Ct. at page 828], unless it can be shown “beyond a reasonable doubt” that the error did not contribute to the jury’s verdict.
With regard to its earlier decision in McMillan, supra, 477 U.S. 79, which held there is no federal constitutional right to a jury determination of a “sentencing factor,” the high court stressed in Apprendi: “We do not overrule McMillan [but instead] . . . limit its holding to cases that do not involve the imposition of a sentence more severe than the statutory maximum for the offense established by the jury’s verdict—a limitation identified in the McMillan opinion itself.” (Apprendi, supra, 530 U.S. at p. 487, fn. 13 [120 S.Ct. at p. 2361].) The court added that it was “reserving] for another day” whether considerations of stare decisis precluded its reconsideration of McMillan. (Ibid.)
In Wims, supra, 10 Cal.4th 293, this court expressly relied on McMillan, supra, 477 U.S. 79. Because McMillan has not been overruled, Wims survives as to sentence enhancement provisions that do not increase the statutorily prescribed maximum penalty for the underlying crime. Thus, a trial court’s failure to instruct on an element of such provisions must on appeal be evaluated under Watson, supra, 46 Cal.2d at page 836, whose harmless error test we discussed on pages 320-321, ante.3
[327]*327B
Does the criminal street gang sentence enhancement increase the penalties for the underlying crimes? Yes, for two categories of felony offenses listed in the enhancement provision.
For certain specified felonies punishable by a determinate term of imprisonment, the criminal street gang enhancement increases the punishment for the offense to an indeterminate term of imprisonment for life. (§ 186.22, subd. (b)(4).) For all other felonies punishable by a determinate term of imprisonment, the enhancement adds a separate term of imprisonment “in addition and consecutive to” the punishment otherwise prescribed for the felony. (§ 186.22, subd. (b)(1), italics added.) Thus, in these two categories, the gang enhancement increases the sentence for the underlying crime beyond its statutory maximum. In these instances, therefore, a trial court’s failure to instruct on an element of the gang enhancement is federal constitutional error (Apprendi, supra, 530 U.S. at p. 490 [120 S.Ct. at pp. 2362-2363]), reviewable under the harmless error standard of Chapman, supra, 386 U.S. at page 24 [87 S.Ct. at page 828], a test we discussed on page 320, ante.
The gang statute has a third category of felony offenses—those that are punishable by an indeterminate term of imprisonment for life. For these felonies, the gang enhancement provision does not alter the indeterminate term of life imprisonment; it merely prescribes the minimum period the defendant must serve before becoming eligible for parole. (§ 186.22, subd. (b)(5) [providing for this category of felonies committed to benefit a street gang, the defendant “shall not be paroled until a minimum of 15 calendar years have been served”].) Thus, for these felonies, the gang enhancement provision does not increase the life term for the underlying offense. Consequently, in this category of cases instructional error on an element of the gang enhancement provision does not violate the federal Constitution (see Apprendi, supra, 530 U.S. at p. 490 [120 S.Ct. at pp. 2362-2363]), but only California law, making the error reviewable under the standard we articulated in Watson, supra, 46 Cal.2d 818, 836, a test we discussed on pages 320-321, ante.
C
Here, the jury convicted defendant of four counts of attempted willful, deliberate, and premeditated murder, as well as one count of grossly negligent discharge of a firearm. With respect to all five offenses, the jury found they were committed to benefit a criminal street gang.
[328]*328The crime of attempted willful, deliberate, and premeditated murder falls within the gang statute’s category of offenses punishable by an indeterminate term of imprisonment for life. As we explained in the preceding part, for these offenses the gang enhancement prescribes only the minimum term before parole eligibility. Before becoming eligible for parole, a defendant who has committed such an offense with a gang enhancement must serve a minimum term of 15 years (§ 186.22, subd. (b)(4)), rather than the minimum term of seven years (§ 3046) required of those convicted of the same offense without the criminal street gang sentence enhancement. There is no increase in the maximum statutory penalty for the crime of attempted murder, which remains “imprisonment in the state prison for life with the possibility of parole.” (§ 664, subd. (a).) Therefore, for this category of offenses instructional error of the type at issue in this case is, for reasons discussed in the preceding section, subject to this court’s harmless error test in Watson, supra, 46 Cal.2d 818, 836.
The crime of gross negligence in discharging a firearm is among the felonies for which the gang enhancement provision sets forth a separate term of imprisonment “in addition and consecutive to” the punishment otherwise prescribed for the offense (§ 186.22, subd. (b)(1)), thus increasing the crime’s statutorily set maximum sentence.4 Therefore, for this offense the trial court’s instructional error here is, for reasons discussed in the preceding section, federal constitutional error and subject to the high court’s harmless error test in Chapman, supra, 386 U.S. at page 24 [87 S.Ct. at page 828]. Accordingly, the Court of Appeal here erred in applying the test of Watson, supra, 46 Cal.2d at page 836, which pertains to state law error.
IV
On remand, the Court of Appeal is to determine with respect to the offense of gross negligence in discharging a firearm whether the trial court’s instructional error was harmless under Chapman (see People v. Breverman (1998) 19 Cal.4th 142, 178-179 [77 Cal.Rptr.2d 870, 960 P.2d 1094])5 and, with respect to the offense of attempted murder, whether the same error was [329]*329harmless under Watson, supra, 46 Cal.2d at page 836. And the court should also reconsider defendant’s claim that the prosecution’s evidence was insufficient to support a jury finding that defendant’s gang, Triple S, was primarily engaged in the commission of one or more offenses specified in the gang statute. In finding the evidence sufficient, the Court of Appeal concluded the prosecution had established that a primary activity of Triple S was committing “gang crimes,” but it failed to identify the felonies comprising the gang’s primary activities. (See § 186.22, subdivision (e) [listing the specific felonies that can satisfy the gang statute’s “primary activities” requirement].)
Disposition
For the reasons stated above, we reverse the judgment of the Court of Appeal and remand the matter to that court for proceedings not inconsistent with this opinion.
It is so ordered.
George, C. J., Baxter, J., Werdegar, J., and Chin, J., concurred.