OPINION
DARDEN, Judge.
STATEMENT OF THE CASE
Michael Greer and John Maggi ("the Plaintiffs") filed an action for a proposed class action lawsuit seeking declaratory and injunctive relief with respect to the Indiana Department of Correction (DOC) policy which provides that individuals con-viected of certain sex or violent offenses requiring registration for a ten-year period must register for an additional ten-year period upon a subsequent conviction for any criminal offense. According to DOC, such additional registration was mandated by statute. Both Greer and Maggi appeal the order that dismissed their action, granted summary judgment to DOC, and denied class action certification.1
We affirm in part and reverse in part.
BACKGROUND
Beginning with "Zachary's Law" in 1994, Indiana has enacted statutes collectively referred to as the Indiana Sex Offender Registration Act that require individuals convicted of sex and certain other offenses to register with local law enforcement agencies. Wallace v. State, 905 N.E.2d 371, 373 (Ind.2009). After July 1, 1995, sex offenders were required to register for "ten years after the date the offender was released from parole, or placed on probation, whichever occurred last," id. at 375 (citing Ind.Code $ 5-2-12-18 (1995) 2); in ensuing years, the statutory framework of that ten-year registration period was repeatedly revised. Beginning July 1, 1994, the failure to register as required was a class A misdemeanor, see P.L. 11-1994 § 7 (adding former I1.C. § 5-212-9). Currently, however, the failure to register constitutes a class D felony. See I.C. § 11-8-8-17. In addition, effective July 1, 2006, a person who has been convicted of certain sex-related crimes is barred from residing within 1,000 feet of school property, a youth program center, or a public park; and knowingly or intentionally doing so constitutes a class D felony. State v. Pol[611]*611lard, 908 N.E.2d 1145, 1147 (Ind.2009) (citing LC. § 35424-113.)
FACTS
In 1991, Greer was convicted of two counts of child molesting. When the offender registry was established, Greer was notified that he would be required to register as a sex offender for a period of ten years after he was paroled. He was paroled in 1996, and he registered as a sex offender in Shelby County. In February 2006, he was notified by DOC that he was no longer required to register because the ten-year period had expired.4 He ceased registering. In April or May of 2006, Greer was arrested for driving under the influence. He was convicted and served time. Upon his release in November 2006, DOC advised him that because he had previously been convicted of the child molesting offenses, he was required to register as a sex offender for a second ten-year period-from his November 2006 release from incarceration and placement on parole until November 2016. Greer registered, and lived in Shelbyville with his grandmother, whose residence was not within the forbidden 1,000-foot statutory proximity to facilities where children are found. After Greer's grandmother died in 2008, he was unable to locate a new residence in Shelbyville that was not within one of the forbidden 1,000-foot statutory zones. On January 17, 2008, Greer filed a class action complaint for declaratory and injunctive relief against the DOC, the Shelby County Sheriff, and the Shelby County Prosecutor.
In 1998, John Maggi was convicted in Illinois of one count of an offense that would constitute possession of child pornography as a class D felony under Indiana law; and he was placed on probation. When he moved to Indiana in 2003, he was notified by DOC that he was required to register as a sex offender for a ten-year period after his 1998 placement on probation. He registered in Newton County, where he was living. In October of 2004, Maggi was arrested for driving under the influence; he pleaded guilty and was sentenced to serve one year on probation. In April of 2008, he was notified by DOC that he was no longer required to register as a sex offender because the ten-year period since he was placed on probation had expired. He ceased registering. In late May of 2008, however, Maggi was notified by DOC that due to his 2004 driving-under-the-influence conviction, he was required to register for a second ten-year period-through October 18, 2014.
On July 28, 2008, the trial court granted leave for Greer's complaint to be amended-adding Maggi as a party plaintiff (and the Newton County Sheriff and Newton County Prosecutor as defendants), and adding claims pertaining to the recent amendment to Indiana Code section 11-8-8-19(a). Before the amendment in 2008, Indiana Code section 11-8-8-19(a) had provided as follows:
. a sex or violent offender is required to register under this chapter until the expiration of ten (10) years after the date the sex or violent offender:
(1) is released from a penal facility (as defined in IC 35-41-1-21) or a secure [612]*612juvenile detention facility of a state or another jurisdiction;
(2) is placed in a community transition program;
(3) is placed in a community corrections program;
(4) is placed on parole; or
(5) is placed on probation; whichever occurs last. The department shall ensure that an offender who is no longer required to register as a sex or violent offender is notified that the obligation to register has expired.
IC. § 11-8-8-19(a). Effective July 1, 2008, pursuant to amendment by Public Law 119-2008 section 8, the statutory provision included the following italicized language:
. a sex or violent offender is required to register under this chapter until the expiration of ten (10) years after the date the sex or violent offender:
(1) is released from a penal facility (as defined in IC 35-41-1-21) or a secure juvenile detention facility of a state or another jurisdiction;
(2) is placed in a community transition program;
(3) is placed in a community corrections program;
(4) is placed on parole; or
(5) is placed on probation;
for the sex or violent offense requiring registration, whichever occurs last. The registration period is tolled during any period that the sex or violent offender is incarcerated. The registration period does not restart if the offender is convicted of a subsequent offense; however, if the subsequent offense is a sex or violent offense, a new registration period may be imposed in accordamee with this chapter. The department shall ensure that an offender who is no longer required to register as a sex or violent offender is notified that the obligation to register has expired.
I.C. § 11-8-8-19(a) (as amended by P.L. 119-1008 § 8).
On July 31, 2008, the Plaintiffs filed their second renewed motion for class action determination.5 On September 15, 2008, the Plaintiffs filed a motion for summary judgment. On September 17 and 19, 2008, the Defendants filed motions to dismiss. On October 17 and 20, 2008, the Defendants filed eross-motions for summary judgment.
On October 31, 2008, the trial court heard arguments on all pending motions. On March 11, 2009, the trial court entered judgment. Its order noted the lack of disputed material facts, and that "many of the same legal issues" were "argued and cross-incorporated [lin their arguments" as to the motions for dismissal and cross-motions for summary judgment. (Plaintiffs App. 55). The trial court granted the Defendants' motions to dismiss and cross-motions for summary judgment and denied the Plaintiffs' motion for summary judgment.6
[613]*613DECISION
Although the Plaintiffs press multiple challenges to the trial court's order,7 we address those we find dispositive.
The Defendants "moved for dismissal on jurisdictional grounds under TR. 12(B)(1), and for failure to state a claim under TR. 12(B)(6)" (Plaintiffs App. 13.) A motion to dismiss for lack of subject matter jurisdiction "presents a threshold question concerning the court's power to act" Perry v. Stitzer Buick GMC, Inc., 637 N.E.2d 1282, 1286 (Ind.1994). The trial court decides whether the requisite jurisdictional facts exist based on its consideration of the complaint, the motion to dismiss, and any affidavits or other evidence submitted. Id. at 1287. Where the facts are not in dispute, we review the trial court's decision de novo. Common [614]*614Council v. Matonovich, 691 N.E.2d 1326, 1328 (Ind.Ct.App.1998), trans. denied.
Our review of the grant of a motion to dismiss for failure to state a claim is also de novo. Charter One Mortg. Corp. v. Condra, 865 N.E.2d 602, 604 (Ind.2007). A motion to dismiss for failure to state a claim tests the legal sufficiency of the claim, not the facts supporting it. Id. at 604. On review, we view the pleadings in the light most favorable to the nonmoving party, with every reasonable inference construed in the nonmovant's favor. Id. A complaint may not be dismissed for failure to state a claim upon which relief can be granted unless it is clear on the face of the complaint that the complaining party is not entitled to relief. Id. at 605.
The trial court held that "sitting in equity," it did "not have jurisdiction to enjoin a criminal prosecution," citing State ex rel. Egan v. Superior Court of Lake County, 211 Ind. 303, 309, 6 N.E.2d 945, 947 (1937), and State ex rel. Fry v. Superior Court of Lake County, 205 Ind. 355, 186 N.E. 310, 313 (1934), and that the Plaintiffs' "exclusive remedy" lay "in the criminal action, if one [were] filed," when they could ask the appropriate court "to terminate the duty to register" pursuant to Indiana Code section 11-8-8-22(c), or to grant relief from the residency bar pursuant to Indiana Code section 35-42-4-11(d). (Plaintiffs' App. 18).
Both Egan and Fry concerned complaints by corporations seeking to enjoin any action against them by prosecutors and law enforcement, and they were more recently cited in Tinder v. Music Operating, Inc., 237 Ind. 33, 46, 142 N.E.2d 610, 617 (1957). All three cases, however, involved corporations and property rights-not individuals seeking relief from the significant personal jeopardy imposed on them by an official policy and law that they challenge on various grounds. Further, Indiana courts have frequently considered challenges to statutory requirements, despite the fact that the plaintiffs were seeking the remedy of an injunction against criminal prosecution. See, e.g., Doe v. Prosecutor, 566 F.Supp. 2d 862 (S.D.Ind.2008) (seeking declaration that requirements unconstitutional and injunction against their enforcement); Big Hat Books v. Prosecutors, 565 F.Supp2d 981 (S.D.Ind.2008) (challenging constitutionality of statute and seeking to enjoin its enforcement); Highland Sales Corp. v. Vance, 244 Ind. 20, 186 N.E.2d 682 (1964).
Moreover, the trial court's reference to statutory remedies appears to presume that the Plaintiffs' sole injury is potential criminal prosecution for failure to comply with the registration requirement. Our Supreme Court recently found, however, that registration itself "imposes significant affirmative obligations and a severe stigma on every person to whom it applies," "resembles the punishment of shaming," and "makes information on all sex offenders available to the general public without restriction and without regard to whether the individual poses any particular future risk." Wallace v. State, 905 N.E.2d at 379, 380, 384.
Nevertheless, citing Wallace wherein the defendant appealed his conviction for failure to register, the Defendants argue that Greer and Maggi may pursue their challenges to registration as a defense in a criminal proceeding if faced with eriminal prosecution for failure to register. The U.S. Supreme Court has declared, however, that a plaintiff need not "first expose himself to actual arrest or prosecution to be entitled to challenge a statute that he claims deters his exercise of constitutional rights." Steffel v. Thompson, 415 U.S. 452, 459, 94 S.Ct. 1209, 39 L.Ed.2d 505 (1974); see also Smith v. Wisconsin Dep't of Agric., 28 F.3d 1134, 1141 (7th Cir.1994) [615]*615("[A] plaintiff should not be required to face the Hobson's choice between forgoing behavior that he believes to be lawful and violating the challenged law at the risk of prosecution."). As the Defendants note, neither Steffel nor Smith actually enjoined criminal prosecution, but we find the stated principle persuasive as applied to the circumstances faced by Greer and Maggi.
Also, the Plaintiffs' complaint sought declaratory relief-a declaration that the DOC policy requiring a second ten-year registration period violated both the state and federal constitutions, and that the residency bar as to Greer violated state and federal ex post facto clauses. The trial court concluded that no declaratory relief was available because statutory procedures provided remedies. The use of a declaratory judgment is discretionary with the trial court and is usually unnecessary where a full and adequate remedy is already provided by another form of action. Dible v. City, 713 N.E.2d 269, 272 (Ind.1999). When considering a motion for declaratory judgment,
the test to be applied is whether the issuance of a declaratory judgment will effectively solve the problem, whether it will serve a useful purpose, and whether or not another remedy is more effective or efficient. The determinative factor is whether the declaratory action will result in a just and more expeditious and economical determination of the entire controversy.
Id. In addition, pursuant to Indiana Trial Rule 57, "The existence of another adequate remedy does not preclude a judgment for declaratory relief in cases where it is appropriate." Id.
In light of the fact that sex offender registration "imposes significant affirmative obligations and a severe stigma on every person to whom it applies," "resembles the punishment of shaming," and "makes information on all sex offenders available to the general public without restriction and without regard to whether the individual poses any particular future risk," Wallace, 905 N.E.2d at 379, 380, 384, we cannot agree with the trial court that declaratory judgment was not appropriate because the plaintiffs could bring their challenges against the statute as a defense should they be prosecuted for failure to register (or, in the case of Greer, failure to comply with the statutory residency restrictions). The burdens imposed by the statutes are such that a possible defense in response to criminal prosecution cannot be considered "a full and complete remedy." Dible, 713 N.E.2d at 272. Accordingly, we conclude that the trial court's holding in that regard must fail.
In addition to granting the Defendants' motions to dismiss, the trial court also granted their motions for summary judgment. The interpretation of a statute presents a pure question of law for which disposition by summary judgment is particularly appropriate. Longa v. Vicory, 829 N.E.2d 546, 547 (Ind.Ct.App.2005). On appeal from the court's decigion in that regard, the issue is a pure question of law. Id. at 548. Therefore, we review the case de novo, and no deference is given to the trial court's judgment. Id.
The Plaintiffs argued that their being required to register for an additional ten-year period after their convictions for an offense that does not require registration is contrary to the statute itself and violates both the Indiana Constitution and the United States Constitution. For the starting point in our review, we note again that only after July 1, 2008, did the following provision of the statute concerning registration contain the italicized language:
. a sex or violent offender is required to register under this chapter until the [616]*616expiration of ten (10) years after the date the sex or violent offender:
(1) is released from a penal facility (as defined in IC 35-41-1-21) or a secure juvenile detention facility of a state or another jurisdiction;
(2) is placed in a community transition program;
(3) is placed in a community corrections program;
(4) is placed on parole; or
(5) is placed on probation;
for the sex or violent offense requiring registration, whichever occurs last. The registration period is tolled during any period that the sex or violent offender is incarcerated. The registration period does mot restart if the offender is convicted of a subsequent offense; however, if the subsequent offense is a sex or violent offense, a new registration period may be imposed in accordance with this chapter. The department shall ensure that an offender who is no longer required to register as a sex or violent offender is notified that the obligation to register has expired.
1.C. § 11-8-8-19(a) (as amended by PL. 119-1008 § 8). Hence, arguably, before July 1, 2008, the statute required registration upon a subsequent conviction for any offense whatsoever (as interpreted by DOC), or simply for an offense that itself required registration under the statute.
The U.S. Supreme Court has held that ambiguity concerning the ambit of criminal statutes should be resolved in favor of lenity. Jones v. U.S., 529 U.S. 848, 120 S.Ct. 1904, 1912, 146 L.Ed.2d 902 (U.S.Ind.2000). Thus, a court does not choose "the harsher alternative" interpretation unless the legislative body "has] spoken in language that is clear and definite." Id. Here, the statutory provision before the 2008 amendment did not "clear[ly] and definite[ly]" specify that after conviction for any subsequent offense, registration as a sex (or violent) offender was required. Id. Also, Indiana's Supreme Court has held that the rule of lenity requires that criminal statutes be strictly construed against the State. Mask v. State, 829 N.E.2d 932, 936 (Ind.2005). The State argues that the statute "is a civil regulation," State's Br. at 85, but Wallace concluded that the registration statute "has a punitive effect despite legislative intent that the statute be regulatory and non-punitive." 905 N.E.2d at 384. Hence, we conclude that the rule of lenity applies.
Pursuant to the rule of lenity, we find it clear that prior to July 1, 2008, the statutory provision at issue contained no lam-guage suggesting that the required registration would be triggered for a second ten-year registration period upon a subsequent conviction. This leads to the logical conclusion that an offender was only required to register again after completion of the ten-year registration period upon conviction for an offense for which the statute requires registration. See City of Carmel v. Steele, 865 N.E.2d 612, 618 (Ind.2007) (presume legislature did not intend statutory language to be applied illogically).
Our conclusion in this regard is reinforced by another consideration: an ambiguous statute should not be interpreted so as to violate the constitution, "because we will not presume that the legislature violated the constitution." Wallace, 905 N.E.2d at 371, 378. Article 1, Section 24 of the Indiana Constitution forbids enactment of any ex post facto law. State v. Pollard, 908 N.E.2d 1145, 1148 (Ind.2009). This ex post facto clause gives effect to "the fundamental principle that persons have a right to fair warning of that conduct which will give rise to criminal penalties." Id. (citing Armstrong v. State, 848 N.E.2d 1088, 1092 (Ind.2006)). Further, [617]*617our Supreme Court's analysis in Wallace held that when the registration statute as applied "imposes burdens that have the effect of adding punishment beyond that which could have been imposed when his crime was committed," it "violates the prohibition on ex post facto laws contained in the Indiana Constitution." Wallace, 905 N.E.2d at 384.
Pursuant to Wallace, to interpret the statute as does DOC and require a second ten-year registration period as a sex offender by either Greer or Maggi would violate the prohibition on ex post facto laws contained in the Indiana Constitution because it would "impose[ ] burdens that have the effect of adding punishment beyond that which could have been imposed when [their] erime[s] w[ere] committed." 905 N.E.2d at 384.
Greer was convicted of child molesting offenses in 1991; registration for the offenses was not even required until July 1, 1994; subsequently, Greer was convicted of driving-under-the-influence in 2006. When he committed the 1991 child molesting offense, he had not received fair warning that his conduct would give rise to having to register as a sex offender. See Pollard, 908 N.E.2d at 1148. Likewise, when he committed the 1991 child molesting offence, he could not have been required to register as a sex offender. See Wallace 905 N.E.2d at 384. Further, when he committed the driving-under-the-influence offense in 2006, the statute did not unambiguously provide that his punishment for doing so could include a see-ond registration period as a sex offender for ten years. Hence, as applied to Greer, the DOC interpretation of the statute would impose on him "burdens beyond that which could have been imposed when his crime was committed." Id.
Even more clearly does the ex post facto analysis apply to whether Maggi was required to register a second time. In 1998, Maggi was convicted of an offense in Illinois that would be the offense of possession of pornography in Indiana. Registration as a sex offender for that particular offense was not required, however, until July 1, 2007. See PL. 216-2007, § 13 (codified at 1.C. § 11-8-8-6(18)). Hence, we find it undisputed that neither when Maggi committed his initial offense in 1998, nor when he committed the subsequent driving-under-the-influence offense in 2004, did the statute require Maggi to register. Therefore, as applied to Maggi, the DOC interpretation of the statute imposed on him "burdens beyond that which could have been imposed when his crime was committed." Wallace, 905 N.E.2d at 384.
Greer also argued to the trial court, as he does on appeal, that application to him of the residency restriction enacted effective July 1, 2006, as a consequence of his 1991 child molesting convictions would likewise violate Indiana's constitutional prohibition of ex post facto laws. He cites our Supreme Court's recent decision in Pollard. 908 N.E.2d 1145. Referring to State v. Pollard, 886 N.E.2d 69 (Ind.Ct.App.2008), vacated by 908 N.E.2d 1145 (Ind.2009), the Defendants respond that the trial court correctly held that Greer's reliance on the Pollard opinion was misplaced because its holding was "linked to ownership of property, not mere residency, and there is no evidence that Greer owns property." (Plaintiffs' App. 21). As indicated, however, the Pollard decision to which both the Defendants and the trial court refer has since been vacated by our Supreme Court's Pollard opinion.
In Pollard, our Supreme Court's analysis was twofold: whether the residency restriction statute evidenced the legislature's intent to impose punishment; and whether the effect of the statute is puni[618]*618tive. 908 N.E.2d at 1149-50. Only in its discussion of the legislature's intent does the opinion mention home ownership-when it notes the lack of any exemption from the restriction as to sex offenders "who owned their homes before the statute's effective date." Id. at 1149. Our Supreme Court then "assum[ed] without deciding that the legislature's intent was to create a civil, non-punitive, regulatory scheme" in enacting the statute, and proceeded to consider seven factors from Kennedy v. Mendoza-Martinez, 372 U.S. 144, 168-69, 83 S.Ct. 554, 9 L.Ed.2d 644 (1968), to determine whether the residency restriction statute had a punitive effect. 908 N.E.2d at 1149-53. It concluded that only two of the factors might indicate that the effects of the residency restriction statute were non-punitive, with the "remaining factors, particularly the factor of exces-siveness" 8 indicating that the statute was punitive in effect. Id. 1154. Pollard had been "charged with, convicted of, and apparently served the sentence for a crime qualifying him as an offender against children before the residency restriction was enacted." Id. Therefore, the statute violated the Indiana Constitution's prohibition of an ex post facto law "as applied to Pollard."
As stated above, Greer was convicted in 1991 and paroled in 1996. Thus, as had Pollard, Greer had "served the sentence for a crime qualifying him as an offender against children before the registration restriction was enacted" in 2006. Id. Accordingly, the statute violated the Indiana Constitution's prohibition of an ex post facto law as applied to Greer.
Finally, we address the Plaintiffs' argument that we should remand to the trial court for a determination of whether class action certification is appropriate. The trial court found that "[blecause this action must be dismissed, class certification is a moot issue"; however, it then proceeded to conclude that "(elven were class certification not a moot point, it would have to be denied because the plaintiffs have not shown that a class action is proper under the applicable rules." (Plaintiffs' App. 22). It proceeded to find that Plaintiffs failed to show that it could satisfy any of the prerequisites for class action representation.9
Whether an action is maintainable as a class action is committed to the sound discretion of the trial court. Associated Med. Networks, Ltd. v. Lewis, 824 N.E.2d 679, 682 (Ind.2005). The representative plaintiffs have the burden to show that all requirements of Indiana Trial Rule 28(A) for class certification have been met. Rene ex rel. Rene v. Reed, 726 N.E.2d 808, 817 (Ind.Ct.App.2000). Specifically, the Rule provides that representatives may sue
as representative parties on behalf of all only if:
(1) the class is so numerous that joinder of all members is impracticable;
(2) there are questions of law or fact common to the class;
(3) the claims or defenses of the representative parties are typical of the claims or defenses of the class; and
[619]*619(4) the representative parties will fairly and adequately protect the interests of the class.
TR. 23(A) (emphasis added). Failure to meet any one of the mandated requirements results in the denial of class status. Rene, 726 N.E.2d at 817.
The trial court expressly found that the "number of people who fit the [proposed class] definition is unknown, failing to show numerosity." (Plaintiffs' App. 24). We find nothing in the record to controvert this conclusion. The trial court further found that the Plaintiffs failed to show "representativeness," as "Greer and Maggi have factual and legal issues that separate them from others" Id. at 25. The tedious nature of some of the statutory history parsed above in order to address the specific statutory provisions applicable, based on the histories of both Greer and Maggi, clearly supports this conclusion by the trial court. Therefore, we find that the trial court did not abuse its discretion when it denied class action certification.
We hold that the trial court erred when it granted summary judgment to the Defendants on the Plaintiffs' claims that they were not required to register as sex offenders for a second ten-year period. We also hold that the trial court erred when it granted summary judgment to the Defendants on Greer's claim that the residency restriction statute violated his ex post fac-to rights under the Indiana Constitution. Accordingly, summary judgment should be granted to the Plaintiffs on these matters. As to the trial court's denial of class action certification, however, we affirm.
Affirmed in part and reversed in part.
ROBB, J., and NAJAM, J., coneur.