Opinion
BROWN, J.A registered sex offender must, within five working days of the offender’s birthday, update his or her registration. (Pen. Code, § 290, subd. (a)(1)(D).)1 Willful failure to update one’s registration is a felony. (§290, subd. (g)(2).) In People v. Barker (2004) 34 Cal.4th 345 [18 Cal.Rptr.3d 260, 96 P.3d 507] (Barker), we held the willfulness element of the offense may not be negated by evidence the defendant “just forgot” to register. (Id. at p. 358.) We reserved judgment “as to whether forgetfulness resulting from, for example, an acute psychological condition, or a chronic deficit of memory or intelligence might negate the willfulness required for a section 290 violation.” (Ibid.) This case presents the question whether forgetting to update one’s registration because of severe depression may negate the section 290 willfulness requirement.
The Attorney General contends willful failure to update one’s registration as a sex offender is a general intent crime, and, therefore, evidence that defendant forgot to update his registration due to depression was inadmissible *69under section 28, subdivision (a).2 Defendant responds that the due process right to present a defense trumps section 28 in the circumstances of this case.
We need not address section 28 or its constitutionality to resolve this case. All we need do is construe section 290. We have been mindful of due process considerations in interpreting section 290. In People v. Garcia (2001) 25 Cal.4th 744 [107 Cal.Rptr.2d 355, 23 P.3d 590] (Garcia), we held that the willfulness element of a section 290 violation requires actual knowledge of the duty to register. We now hold that the willfulness element of the offense may be negated by evidence that an involuntary condition—physical or mental, temporary or permanent—deprived a defendant of actual knowledge of his or her duty to register. Only the most disabling of conditions, we emphasize, would qualify under the standard we announce today. Severe Alzheimer’s disease is one example that comes to mind; general amnesia induced by severe trauma is another. Defendant’s claimed depression clearly did not satisfy this standard. Defendant knew of his obligation to register and, had he taken it to heart, he could have managed to discharge it.
Factual and Procedural Background
Defendant is a registered sex offender, and so must update his registration within five working days of his birthday. (§ 290, subd. (a)(1)(D).) Defendant’s birthday is December 6; in 2001, he did not update his registration until December 22. He voluntarily came to the Pacifica police station to do so. According to the officer who interviewed him, defendant said “he had simply forgotten to.” Defendant added he had “gotten up that morning, realized he hadn’t registered and that he needed to do so.”
While defendant claims to have forgotten to register on this occasion, there is no question but that he was ordinarily well aware of his obligation. He had complied with it on numerous occasions in the past. He was, he testified, “stunned” he had forgotten to update his registration this time. “It was something I don’t usually forget at all. I’m constantly reminded of it every day.” Indeed, defendant asserted he would “never forget” the day he was first required to register as a sex offender.
The indelibility of that day for defendant is apparently attributable to the fact that this lifetime obligation has never ceased to chafe him. In 1988, in *70signing an acknowledgment that he had been notified of the sex offender registration requirements, he wrote he was doing so “under duress.” In 1999, in initialing the registration form’s 16 statements advising him of his various obligations, including his obligation to update his registration “within 5 working days of my birthday,” defendant complained: “Registering is having a negative effect on me. It’s not fair to be classified as such a sex freak for an isolated incident [his conviction for rape in 1983].” Defendant renewed this complaint in signing the registration form some months before this incident.
At trial, defendant testified he forgot to update his registration because he was “in a pretty depressed state due to many issues.” His counsel asked him, “What were those issues?” However, the prosecutor’s objection on grounds of relevancy was sustained. Earlier, the court had foreclosed this line of inquiry by granting the prosecutor’s motion in limine; the ground of the ruling was that failure to update one’s sex offender registration is a general intent crime.
According to defendant’s proffers of evidence, friends of his were prepared to testify he was depressed because (1) his mother had cancer; (2) the mother of his son, in order to terminate his visitation rights, had falsely accused him of being abusive to the boy; (3) he had broken up with his girlfriend; and (4) his dog had died. In his argument opposing the motion in limine, defense counsel said the testimony of defendant’s friends, as to “what he was going through at the time,” would lay the foundation for an expert witness who would testify (1) that defendant was “showing signs of clinical depression,” and (2) how depression affects “concentration and memory.”
Finding defendant guilty of willfully failing to update his registration (§ 290, subd. (g)(2)), the court suspended imposition of sentence and granted defendant probation for three years, subject to, among others, the condition that he pay a restitution fine of $200 (§ 1202.4), and that he serve 90 days in the county jail with credit for time served.
The Court of Appeal reversed. “We agree with [defendant] that genuinely forgetting to register negates the element of willfulness required in section 290, and therefore, the trial court erred in refusing to admit testimony that [defendant] failed to remember to register.”
We reverse the judgment of the Court of Appeal, and we remand the cause for further proceedings consistent with the views expressed herein.
*71Discussion
Again, in Garcia, supra, 25 Cal.4th 744, we held that a violation of section 290 requires actual knowledge of the duty to register. “In a case like this, involving a failure to act, we believe section 290 requires the defendant to actually know of the duty to act. Both today and under the version applicable to defendant, a sex offender is guilty of a felony only if he ‘willfully violates’ the registration or notification provisions of section 290. (§ 290, former subd. (g)(3), as amended by Stats. 1994, ch. 867, § 2.7, p. 4393; § 290, present subd. (g)(3).) The word ‘willfully’ implies a ‘purpose or willingness’ to make the omission. (§ 7.) Logically one cannot purposefully fail to perform an act without knowing what act is required to be performed. As stated in People v. Honig (1996) 48 Cal.App.4th 289, 334 [55 Cal.Rptr.2d 555], ‘the term “willfully” . . . imports a requirement that “the person knows what he is doing.” [Citation.] Consistent with that requirement, and in appropriate cases, knowledge has been held to be a concomitant of willfulness. [Fn. omitted.]’ Accordingly, a violation of section 290 requires actual knowledge of the duty to register. A jury may infer knowledge from notice, but notice alone does not necessarily satisfy the willfulness requirement.” (Garcia, at p. 752.)
We further held in Garcia that as construed to require actual knowledge of one’s duty to register, section 290 satisfies due process. “The actual knowledge test satisfies constitutional requirements. The high court has held that due process principles forbid applying the proscriptions of a registration act to one having ‘no actual knowledge of his duty to register, and where no showing is made of the probability of such knowledge.’ (Lambert v. California (1957) 355 U.S. 225, 227 [2 L.Ed.2d 228, 78 S.Ct. 240] (Lambert).) . . . [f] Assuming Lambert controls here (but see U.S. v. Kafka (9th Cir. 2000) 222 F.3d 1129, 1132-1133 [.Lambert does not apply where the circumstances, including any notice expressly or impliedly provided by the criminal statute, should have alerted defendant to the registration requirement]; U.S. v. Meade (1st Cir. 1999) 175 F.3d 215, 226 [same]), it merely established that a defendant cannot be convicted of violating a registration act without at least ‘proof of the probability of’ knowledge of the duty to register. {Lambert, supra, 355 U.S. at p. 229 [78 S.Ct at p. 243].) By making actual knowledge of the duty to register an element of a section 290 violation, we undoubtedly meet any due process limitations imposed by Lambert.” {Garcia, supra, 25 Cal.4th at pp. 752-753.)
*72In People v. Atkins (2001) 25 Cal.4th 76 [104 Cal.Rptr.2d 738, 18 P.3d 660], we rejected the argument that exclusion of evidence, under section 22,3 of the defendant’s voluntary intoxication “violate[d] his due process rights by denying him the opportunity to prove he did not possess the required mental state (Montana v. Egelhoff (1996) 518 U.S. 37, 39-40, 56 [135 L.Ed.2d 361, 116 S.Ct. 2013].)” (Atkins, at p. 93.)
We recognize, of course, that depression, unlike drunkenness, is not a voluntary condition. And we realize a person may suffer from an involuntary condition so disabling as to rob him of knowledge of his registration obligations under section 290. Therefore, in order to avoid any due process problems, we hold that a defendant charged with violation of section 290 may present substantial evidence that, because of an involuntary condition— temporary or permanent, physical or mental—he lacked actual knowledge of his duty to register.
Defendant did not proffer such evidence. There is no question but that he knew of his duty to register. He simply claimed his depression made it more difficult for him to remember to register. However, life is difficult for everyone. As a society, we have become increasingly aware of how many of our fellow citizens must cope with significant physical and mental disabilities. But cope they do, as best they can, for cope they must. So, too, must defendant and other sex offenders learn to cope by taking the necessary measures to remind themselves to discharge their legally mandated registration requirements. It is simply not enough for a defendant to assert a selective impairment that conveniently affects his memory as to registering, but otherwise leaves him largely functional.
The public policy underlying section 290 supports this conclusion. In Barker, supra, 34 Cal.4th 345, we explained that countenancing the excuse that a defendant just forgot to register “ ‘would effectively “eviscerate” ’ ” section 290. (Barker, at p. 358.)
“ ‘The purpose of section 290 is to assure that persons convicted of the crimes enumerated therein shall be readily available for police surveillance at all times because the Legislature deemed them likely to commit *73similar offenses in the future. [Citation.]’ (Barrows v. Municipal Court (1970) 1 Cal.3d 821, 825-826 [83 Cal.Rptr. 819, 464 P.2d 483]; accord, Wright [v. Superior Court (1997)] 15 Cal.4th [521,] 527 [63 Cal.Rptr.2d 322, 936 P.2d 101]; People v. McClellan (1993) 6 Cal.4th 367, 376, fn. 7 [24 Cal.Rptr.2d 739, 862 P.2d 739].) ‘Plainly, the Legislature perceives that sex offenders pose a “continuing threat to society” [citation] and require constant vigilance. [Citation.]’ (Wright, at p. 527.)
“ ‘To this end, a convicted sex offender must register not only on conviction, but whenever “coming into any city, county, or city and county in which he or she temporarily resides or is domiciled . . . .” (§ 290, subd. (a).) Supplemental address change information helps law enforcement agencies keep track of sex offenders who move within the same city or county or are transient. In large cities such as Los Angeles or huge counties like San Bernardino, where offenders can easily relocate without reregistering, section 290[, subdivision (f)] seeks to prevent them from disappearing from the rolls. Ensuring offenders are “readily available for police surveillance” {Barrows v. Municipal Court, supra, 1 Cal.3d at p. 825) depends on timely change-of-address notification. Without it law enforcement efforts will be frustrated and the statutory purpose thwarted. The statute is thus regulatory in nature, intended to accomplish the government’s objective by mandating certain affirmative acts. Compliance is essential to that objective; lack of compliance fataV {Wright, supra, 15 Cal.4th at p. 527, italics added.)” {Barker, supra, 34 Cal.4th at p. 357.)
Just as it would effectively eviscerate the statute to permit sex offenders to escape the consequences of failing to register on the ground they simply forgot to do so {Barker, supra, 34 Cal.4th at p. 358), so, too, would it effectively eviscerate the statute to countenance as an excuse a condition that falls short of nullifying knowledge of one’s registration obligations. As for defendant’s claimed depression, according to one study, most convicted sex offenders have mood disorders, and nearly a quarter of them suffer from major depression.4 Indeed, defendant claimed the very act of registering had a “negative effect” on him.
Finally, defendant contends it was for a jury, not the trial judge, to decide whether his depression deprived him of actual knowledge of his duty to register. We disagree. The question whether a defendant has proffered evidence sufficiently substantial to go to the jury under the standard we announce today is a question confided to the sound discretion of the trial court. For the reasons given, we find no abuse of discretion here.
*74Disposition
The judgment of the Court of Appeal is reversed and the cause remanded for further proceedings consistent with the views expressed herein.
George, C. J., Baxter, J., and Chin, J., concurred.
Subsequent statutory references are to the Penal Code.
Section 28, subdivision (a) provides: “Evidence of mental disease, mental defect, or mental disorder shall not be admitted to show or negate the capacity to form any mental state, including, but not limited to, purpose, intent, knowledge, premeditation, deliberation, or malice aforethought, with which the accused committed the act. Evidence of mental disease, mental defect, or mental disorder is admissible solely on the issue of whether or not the accused actually formed a required specific intent, premeditated, deliberated, or harbored malice aforethought, when a specific intent crime is charged.”
Section 22 provides in relevant part: “(a) No act committed by a person while in a state of voluntary intoxication is less criminal by reason of his or her having been in that condition. Evidence of voluntary intoxication shall not be admitted to negate the capacity to form any mental states for the crimes charged, including, but not limited to, purpose, intent, knowledge, premeditation, deliberation, or malice aforethought, with which the accused committed the act.
“(b) Evidence of voluntary intoxication is admissible solely on the issue of whether or not the defendant actually formed a required specific intent, or, when charged with murder, whether the defendant premeditated, deliberated, or harbored express malice aforethought.”
McElroy et al., Psychiatric Features of 36 Men Convicted of Sexual Offenses (June 1999) 60 J. Clinical Psychiatry 414, 417, table 2.