I join the majority in holding polygraph evidence inadmissible. I disagree, however, with its conclusion upholding the constitutionality of the statutory provisions concerning battery on a custodial officer.
Two statutory provisions concerning battery on a custodial officer are at issue here: Penal Code section 243.1 makes battery on a custodial officer a felony, whether or not the battery caused injury to the custodial officer.1 (For convenience, I sometimes refer to the offense defined by section 243.1 as battery on a custodial officer without injury, because injury is not an element of the offense.) Subdivision (c) of section 243 (hereafter section 243(c)), by comparison, makes a battery on a custodial officer that results in injury to the custodial officer an offense punishable either as a felony or as a misdemeanor. (For convenience, I sometimes refer to this offense as battery on a custodial officer with injury.) Although battery on a custodial officer with injury is on its face more egregious than battery on a custodial officer without injury, it carries a lesser minimum penalty (it may be punished as a misdemeanor) and the same maximum penalty. In this respect, the statutory scheme lacks any *853rational basis, in my view, and thereby violates the constitutional guarantee of equal protection of the laws.
I
“ ‘The first prerequisite to a meritorious claim under the equal protection clause is a showing that the state has adopted a classification that affects two or more similarly situated groups in an unequal manner.’ ” (Cooley v. Superior Court (2002) 29 Cal.4th 228, 253 [127 Cal.Rptr.2d 177, 57 P.3d 654], quoting In re Eric J. (1979) 25 Cal.3d 522, 530 [159 Cal.Rptr. 317, 601 P.2d 549]; accord, People v. Wutzke (2002) 28 Cal.4th 923, 943 [123 Cal.Rptr.2d 447, 51 P.3d 310].) In this case, persons who commit the same illegal act—a battery on a custodial officer causing injury—are in that respect similarly situated, but they are treated differently depending on whether they are charged under section 243.1, which does not require proof of injury, or under section 243(c), which does. The Attorney General’s assertion that persons who commit identical acts with the identical mental states but are charged under different statutes are not similarly situated is incorrect when the equal protection issue is the constitutionality of the distinction between the two statutes. (People v. Nguyen (1997) 54 Cal.App.4th 705, 714—715 [63 Cal.Rptr.2d 173].)
As the majority observes (maj. opn., ante, at p. 838), under the federal and state equal protection clauses the constitutionality of the statutory scheme at issue turns on whether there is a rational basis for the distinction it draws between persons prosecuted under section 243.1 (battery on a custodial officer without injury) and section 243(c) (battery on a custodial officer with injury).2 (See Kasler v. Lockyer (2000) 23 Cal.4th 472, 514 [97 Cal.Rptr.2d 334, 2 P.3d 581] (cone. & dis. opn. of Kennard, J.).) The equal protection clause “does not forbid classifications,” but it does forbid “governmental decisionmakers from treating differently persons who are in all relevant respects alike.” (Nordlinger v. Hahn (1992) 505 U.S. 1, 10 [120 L.Ed.2d 1, 112 S.Ct. 2326]; see Easier y. Lockyer, supra, at p. 515 (cone. & dis. opn. of Kennard, J.).)
II
The relevant statutory provisions are these:
Section 243.1 declares that battery “committed against the person of a custodial officer” is a felony when the person committing the battery “knows *854or reasonably should know that the victim is a custodial officer engaged in the performance of his or her duties.”
Section 243, subdivision (b), makes the same conduct a misdemeanor. It prescribes' misdemeanor punishment for a battery “committed against the person of a . . . custodial officer . . . engaged in the performance of his or her duties . . . and the person committing the offense knows or reasonably should know that the victim is a . . . custodial officer
Section 243(c) describes more egregious conduct. It requires a battery “committed against a custodial officer . . . engaged in the performance of his or her duties” when “the person committing the offense knows or reasonably should know that the victim is a . . . custodial officer . . . and an injury is inflicted on that victim.” (Italics added.) Violation of section 243(c) is punishable as either a felony or a misdemeanor, in the discretion of the trial court. (Such crimes are colloquially referred to as “wobblers.”)
Finally, section 243, subdivision (d), not directly relevant here, describes an even more serious crime; battery on a custodial officer resulting in serious bodily injury. Violation of this provision too can be punished as either a felony or a misdemeanor.
Traditionally, California’s sentencing laws have punished more harshly crimes that cause injury than similar crimes that do not. The statutory scheme at issue here, however, goes against this pattern. As the Court of Appeal majority observed, “[t]he current scheme encourages arbitrary, irrational charging.” In the case of a battery on a custodial officer that causes injury, there would be no incentive for the prosecutor to charge the defendant under section 243(c) (battery on a custodial officer with injury). By ignoring the injury and charging the defendant under section 243.1 (battery on a custodial officer without injury), the prosecutor is spared the burden of proving the injury and the trial court is precluded from treating the offense as a misdemeanor, an option that would be available to the court if the defendant had been charged with, and convicted of a violation of section 243(c) (battery on a custodial officer with injury).3
*855Other consequences of the statutory scheme are even more perplexing, as illustrated by the problems involved in instructing a jury in the trial of a defendant charged with a violation section 243(c) (battery on a custodial officer with injury). A trial court must instruct the jury on a lesser included offense when the evidence raises a question whether all of the elements of the charged crime are present, and the evidence would support a conviction of the lesser offense. (People v. Bradford (1997) 14 Cal.4th 1005, 1055 [60 Cal.Rptr.2d 225, 929 P.2d 544].) “[A] lesser offense is necessarily included in a greater offense if either the statutory elements of the greater offense, or the facts actually alleged in the accusatory pleading, include all the elements of the lesser offense, such that the greater cannot be committed without also committing the lesser.” (People v. Birks (1998) 19 Cal.4th 108, 117 [77 Cal.Rptr.2d 848, 960 P.2d 1073].) Because a defendant cannot commit battery on a custodial officer with injury (§ 243(c)) or battery on a custodial officer causing serious bodily injury (§ 243, sub. (d)) without committing all elements of battery in violation of section 243.1 (battery on a custodial officer without injury), the latter is an offense necessarily included in the crimes of battery on a custodial officer with injury or with serious bodily injury. Consequently, when a defendant is charged with a battery on a custodial officer with injury or serious bodily injury, and there is a question whether the injury occurred, the trial court must instruct on the necessarily included offense of battery in violation of section 243.1 (battery on a custodial officer without injury). If the jury then found the defendant guilty as charged of a battery on a custodial officer causing injury (§ 243(c)), the court would have discretion to impose a misdemeanor sentence. But if the jury, because it entertained a reasonable doubt that the battery had caused an injury to the custodial officer, found the defendant guilty only of the necessarily included offense of battery on a custodial officer (§ 243.1), the trial court would be required to sentence the defendant as a felon.
I can perceive no rational basis for this rather startling statutory scheme. The majority does, however.
The majority first questions whether the offense defined in section 243.1 (battery on a custodial officer without injury) is actually less serious than the offense defined in section 243(c) (battery on a custodial officer with injury). It observes that if we compare two different batteries, it is possible that a particular battery without injury could be more heinous than another battery that did cause an injury. (See maj. opn., ante, at pp. 839-840.) By the same reasoning, however, a particular petty theft could, depending on the circumstances, be more serious than a particular grand theft, and a particular grand theft could be more serious than a particular robbery, and so forth. Under this reasoning, the legal classification of crimes as inherently “greater” or “lesser” becomes meaningless and a rational ordering of crimes and punishment in the penal law becomes impossible. In deciding which of two crimes is the *856greater, the only meaningful comparison is between the elements of each crime, as I discussed at pages 853-855, ante, not the particular circumstances of their commission.
The majority also questions defendant’s claim that the statutory scheme allows a battery on a custodial officer without injury to be punished more severely than one with injury. The majority points out that the maximum punishment under both section 243.1 (battery on a custodial officer without injury) and section 243(c) (battery on a custodial officer with injury) is the same—three years. (See maj. opn., ante, at p. 839.) But the majority cites neither authority nor reason for the proposition that when comparing statutes for the purpose of equal protection analysis a court should examine only the maximum punishment and ignore everything else. Here the minimum punishment specified under section 243.1 (battery on a custodial officer without injury) is 16 months in state prison (§ 18) while the minimum punishment under section 243(c) (battery on a custodial officer with injury) is “a fine of not more than two thousand dollars ($2000) [or] imprisonment in a county jail not exceeding one year.” When, as here, the defendant’s crime could reasonably be treated as a misdemeanor, it is the minimum punishment that is more important.
The majority holds that section 243.1 (battery on a custodial officer without injury) does not violate the principle of equal protection of the laws because the Legislature could have rationally concluded that reduction of this offense to a misdemeanor is not appropriate whenever the prosecutor deems the offense serious enough for felony prosecution. (Maj. opn., ante, at p. 840.) This reasoning misses the point. Equal protection analysis requires comparing two statutes—here section 243.1 (battery on a custodial officer without injury) and section 243(c) (battery on a custodial officer with injury). The majority offers no rational basis for the distinction between them.4
I perceive no rational basis for giving trial courts the power to punish as a misdemeanor a charge of battery on a custodial officer with injury, but to *857deny that power as to battery on a custodial officer without injury under section 243.1. Could the Legislature rationally believe that some batteries without injury are so serious that the prosecutor must be given unfettered, unreviewable power to ensure that they are prosecuted as felonies, but that this is not the case for batteries causing injury? Conversely, could the Legislature rationally believe that the courts could be trusted to determine when batteries causing injury should be treated as felonies rather than misdemeanors, but could not be trusted to make the same determination as to batteries that did not cause injury? The answer is inescapable: the statutory distinction has no rational basis, thus denying defendant the equal protection of the laws.
The allegations of defendant’s petition for habeas corpus filed in conjunction with defendant’s appeal, if true,5 belie the majority’s assumption that prosecutors will charge the felony offense of battery on a custodial officer without injury under section 243.1 only when they deem the offense serious enough to warrant felony punishment. Here, after charging defendant with a felony battery under section 243.1, the prosecutor offered to dismiss the felony charge if defendant would plead guilty to a misdemeanor battery, which would be further reduced to an infraction if she successfully completed probation. Defense counsel refused the offer. The prosecutor then offered to dismiss the battery charge if defendant would plead guilty to the misdemeanor of driving under the influence of alcohol or drugs (Veh. Code, § 23152). Defense counsel rejected this offer as well. The case was then prosecuted as a felony. The trial court expressed dismay that the case had not been settled, and, after the jury found defendant guilty as charged, the court placed defendant on probation instead of sending her to prison for the felony conviction.
If true, these facts show that the prosecutor did not consider defendant’s conduct so egregious as to require felony punishment. A prosecutor taking that view would not have been so eager to induce defendant to plead guilty to crimes punishable only as misdemeanors. But because defendant was charged *858under section 243.1, a mandatory felony, the trial court was prevented from exercising the discretion the Legislature gave it to treat the more serious crime of battery on a custodial officer with injury (§ 243(c)) as a misdemeanor. This kind of injustice is the predictable result of the current irrational statutory scheme.
I would affirm the Court of Appeal.
Statutory citations are to the Penal Code, unless otherwise noted.
If two groups are not similarly situated, then any “equal protection claim cannot succeed, and does not require further analysis.” (People v. Nguyen, supra, 54 Cal.App.4th at p. 714.) Thus, by applying a rational basis test, the majority here implicitly acknowledges that the two groups—persons charged under section 243.1 and those charged under section 243(c)—are similarly situated.
Although the prosecutor has no incentive to charge a defendant with battery on a custodial officer with injury (§ 243(c)), there would still be an incentive to charge a defendant with battery causing serious bodily injury (§ 243, subd. (d)) because that offense, although a wobbler, has a higher maximum penalty than of offense defined by section 243.1 (battery on a custodial officer without injury).
The majority mistakenly relies on United States v. Batchelder (1979) 442 U.S. 114 [60 L.Ed.2d 755, 99 S.Ct. 2198], a case involving a federal statutory scheme that defined two crimes with essentially the same elements but different penalties. The United States Supreme Court concluded that the federal scheme did not deny equal protection to a defendant convicted of the crime carrying the greater penalty. (Id. at pp. 124-125.) The court was not faced with a statutory scheme like the one at issue here, which defines two closely related crimes and permits lesser punishment for the crime that differs only in requiring one additional aggravating element. The high court in Batchelder thus had no occasion to decide whether a statutory scheme with those irrational features violated the constitutional guarantee of equal protection of the laws. I note, moreover, that the Colorado Supreme Court found the reasoning in Batchelder unpersuasive and declined to follow it in construing the equal protection clause of its own state constitution. (People v. Estrada (1979) 198 Colo. 188 [601 P.2d 619, 621].)
The truth of these allegations may be determined at an evidentiary hearing ordered by the Court of Appeal on the habeas corpus petition defendant filed in conjunction with her appeal. At issue there is whether defense counsel failed to consult with defendant before rejecting the prosecution’s offers to dismiss the felony charge if defendant would plead guilty to either of two misdemeanors, battery or driving under the influence.