Undoubtedly, Penal Code section 2901 would benefit from a substantial rewriting. I cannot agree, however, that subdivision (f), read in conjunction with subdivision (a)(1), is fatally ambiguous or did not adequately inform defendant of the obligation to notify authorities of his change of address *257when he moved to Texas. To reach a contrary conclusion, the majority has resorted to linguistic contortions only a sophist could love and disregarded the only reasonable interpretation of the statutory language. Worse yet, it has construed section 290(a)(1) to undermine the Legislature’s recent amendment to section 290(f), which would otherwise have placed beyond cavil the duty to notify of any change of address regardless of the registrant’s new location. (See Stats. 1998, eh. 930, § 1.1.)
Section 290(f) provided in relevant part: “If any person who is required to register pursuant to this section changes his or her residence address, the person shall inform, in writing within 10 days, the law enforcement agency or agencies with whom he or she last registered of the new address.” (See fn. 1, ante.) The majority’s construction of this provision to absolve defendant of his responsibility is flawed in several respects: First, it necessarily reads into the statute a limitation not imposed by the Legislature—that notification is required only when the person “changes his or her residence address within California.” We have previously described section 290 as a “comprehensive statutory scheme” (Wright v. Superior Court (1997) 15 Cal.4th 521, 528 [63 Cal.Rptr.2d 322, 936 P.2d 101] (Wright)) “ ‘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 similar offenses in the future.’ [Citation.]” (Id. at p. 527.) Accomplishing this goal “depends on timely change-of-address notification.” (Ibid.) Courts should thus avoid construing any provision more narrowly than the express statutory language demands. (See also Code Civ. Proc., § 1858 [“In the construction of a statute . . . , the office of the Judge is simply to ascertain and declare what is in terms or in substance contained therein, not to insert what has been omitted . . . .”].)
Second, the majority’s construction confuses who must register with when the registration obligation applies. Under section 290(a)(1), a person required to register was “[e]very person described in [section 290, subdivision (a)(2),]” including those, such as defendant, who committed certain enumerated sex offenses. “[W]hile residing in California” is a separate and distinct proviso, which qualifies the mandate that a sex offender is subject to section 290 “for the rest of his or her life.” (§ 290(a)(1); see fn. 1, ante.) “The meaning of a statute may not be determined from a single word or sentence; the words must be construed in context, and provisions relating to the same subject matter must be harmonized to the extent possible. [Citation.]” (Lungren v. Deukmejian (1988) 45 Cal.3d 727, 735 [248 Cal.Rptr. 115, 755 P.2d 299]; see also United States v. Brown (1948) 333 U.S. 18, 25-26 [68 S.Ct. 376, 379-380, 92 L.Ed. 442].) A plain reading of the statute as a whole, *258unobscured by legalistic parsing, leads not to ambiguity but to one reasonable conclusion: section 290(f) applied whenever there was a change of address unless the registrant was already residing outside California.
Nevertheless, defendant insists, and the majority accepts, that the statute was sufficiently ambiguous to excuse his noncompliance because “within 10 days” (§ 290(f)) after he left for Texas, he was no longer “residing in California.” (§ 290(a)(1).) “ ‘Residence, as used in the law, is a most elusive and indefinite term. It has been variously defined. ... To determine its meaning, it is necessary to consider the purpose of the act.’ [Citations.]” (Smith v. Smith (1955) 45 Cal.2d 235, 240 [288 P.2d 497].) Defendant’s attempt to capitalize on the most favorable of the various legal definitions of “residence” does not establish ambiguity when the commonsense meaning is otherwise clear. Moreover, it is inconsistent with the legislative intent underlying the registration statute as a whole and the integral function of the address change notification requirement. (See Wright, supra, 15 Cal.4th at pp. 526-527.) Given the “ ‘continuing threat to society’ ” posed by sex offenders (id. at p. 527), official knowledge of their whereabouts is imperative. That concern does not significantly diminish when they cross state lines so as to eliminate the need for change-of-address information. (See, e.g., 42 U.S.C. § 14071.)2
The majority’s analysis further confuses when the notification duty arises and when a violation occurs. (See Wright, supra, 15 Cal.4th at p. 526.) The obligation arises as soon as the registrant departs for a new location, at which point—under any reasonable interpretation—he is still residing in California. (Ibid.) A violation occurs 10 days thereafter but only if the offender has failed to notify authorities of the address change. The 10-day interval is a grace period “employed to discourage premature police action and allow a reasonable time to accomplish registration . . . .” (In re Parks (1986) 184 Cal.App.3d 476, 480 [229 Cal.Rptr. 202].) It is not a “King’s X” permitting a person coming within the statute’s ambit to divest himself of *259residence status and notice requirements with impunity.3 (Cf. Wright, supra, 15 Cal.4th at pp. 526-527.) When the Legislature has gone to such lengths to bring every anticipated circumstance within the scope of section 290 (see, e.g., § 290, subd. (a)(1)(A), as amended by Stats. 1997, ch. 820, § 1 [requiring registration even if the sex offender “has no residence”]), it is all the more anomalous to construe an act of legislative forbearance as license to evade the notification requirement.
Finally, the most serious consequence of the majority’s construction is not that it permits defendant, a sex offender of the most egregious type,4 to evade punishment for flouting his obligations under section 290. It has effectively nullified the recent amendment intended to address the very question raised by this case. Section 290, subdivision (f)(1) now requires a registrant to notify of a change of address “whether within the jurisdiction in which he or she is currently registered or to a new jurisdiction inside or outside the state . . . ,”5 (Stats. 1998, ch. 930, § 1.1.) The majority apparently assumes this has rectified the “ambiguity” pressed by defendant. However, because the majority has defined a “person required to register pursuant to this section” as a function of “while residing in California” (rather than the enumerated categories of section 290, subdivision (a)(2)), defendants who move out of state can now cite this opinion to successfully argue that they had no notification duty even under the current version of section 290(f). That is, as long as they relocate within five working days, they are not “residing in California” (§ 290(a)(1)) and therefore not required to register pursuant to this section.
In reversing the Court of Appeal’s judgment, the majority invokes the principle that ambiguity in a criminal statute should be resolved in favor of the defendant. While generally true, “it must be emphasized that the canon entitles the defendant only to the benefit of every realistic doubt. This rule of construction ‘ “is not an inexorable command to override common sense and evident statutory purpose. It does not require magnified emphasis upon a single ambiguous word in order to give it a meaning contradictory to the fair *260import of the whole remaining language.” ’ [Citations.]” (.People v. Anderson (1987) 43 Cal.3d 1104, 1145-1146 [240 Cal.Rptr. 585, 742 P.2d 1306]; see § 4 [“All [Penal Code] provisions are to be construed according to the fair import of their terms, with a view to effect its objects and to promote justice.”].) The “ambiguity” discerned by the majority is nothing more than defendant’s casuistry. In mistaking the one for the other, the majority has ignored the plain meaning of the statute and done a grave disservice to the legislative goals section 290 is intended to promote.
Baxter, J., concurred.
All statutory references are to the Penal Code. All section 290 references are to the version of the statute in effect at the time of defendant’s offense, unless otherwise indicated. (See Stats. 1994, ch. 867, § 2.7.) As relevant here, section 290, subdivision (a)(1) (section 290(a)(1)), provided: “Every person described in paragraph (2), for the rest of his or her life while residing in California, shall be required to register . . . within 14 days of coming into any county, city, or city and county in which he or she temporarily resides or is domiciled for that length of time. The person shall be required annually thereafter, within 10 days of his or her birthday, to update his or her registration with the entities described in this paragraph . . . .” Section 290, subdivision (f) (section 290(f)), provided: “If any person who is required to register pursuant to this section changes his or her residence address, the person shall inform, in writing within 10 days, the law enforcement agency or agencies with whom he or she last registered of the new address. The law enforcement agency or agencies shall, within three days after receipt of this information, forward it to the Department of Justice. The Department of Justice shall forward appropriate registration data to the law enforcement agency or agencies having local jurisdiction of the new place of residence.”
Title 42 United States Code section 14071 conditions a state’s receipt of certain federal funding on compliance with the Jacob Wetterling Crimes Against Children and Sexually Violent Offender Registration Program. In particular, it mandates that “[a] person who has been convicted of an offense [including child molestation] which requires registration under this section and who moves to another State, shall report the change of address to the responsible agency in the State the person is leaving, and shall comply with any registration requirement in the new State of residence. The procedures of the State the person is leaving shall ensure that notice is provided promptly to an agency responsible for registration in the new State, if that State requires registration.” (42 U.S.C. § 14071(b)(5).) Heretofore, the Legislature has assumed section 290 conformed to this requirement. (See Stats. 1997, ch. 818, §D
Ironically, but not surprisingly, in Wright, the defendant argued that the 10-day period was the only time within which a violation of section 290(f) could occur. (15 Cal.4th at pp. 529-530.)
Defendant was required to register pursuant to section 290 as a result of his conviction for lewd and lascivious conduct with a child under the age of 14 (§ 288, subd. (a)) and sodomy with a child under the age of 14 (§ 286, subd. (c)).
In full, the current version of section 290, subdivision (f)(1), provides in relevant part: “If any person who is required to register pursuant to this section changes his or her residence address or location, whether within the jurisdiction in which he or she is currently registered or to a new jurisdiction inside or outside the state, the person shall inform, in writing within five working days, the law enforcement agency or agencies with which he or she last registered of the new address or location.”