KELLY, Associate Judge:
Appellant Michael A. Jones is a mental patient at St. Elizabeths Hospital where he has been committed since March 1976, pursuant to D.C.Code 1973, § 24-301(d).1 In February 1977, he appealed from an order by Judge Eugene N. Hamilton denying his request for immediate release from St. Eliz-abeths or in the alternative for civil commitment in accordance with the procedures set forth in D.C.Code 1973, § 21-545(b),2 basing his challenge to his continued confinement on the argument that detention beyond the maximum period for which he could have been imprisoned for the offense of which he was acquitted denies him equal protection of the laws.
Our first panel opinion, which relied on an express abstention from a challenge to his initial commitment, held that appellant had no right to the relief requested. Jones v. United States, D.C.App., 396 A.2d 183 (1978). Appellant petitioned for rehearing or rehearing en banc, objecting to the panel’s decision as unfairly based on his abstention from a challenge to the initial commitment under D.C.Code 1973, § 24-301(d)(2). Rehearing was thereafter granted and a second opinion issued holding that appellant was entitled to immediate release unless the government civilly committed him pursuant to D.C.Code 1973, § 21-545(b) because the “release hearing procedure is to some extent ‘punitive’ ” and it would be a denial of equal protection to confine appellant under criminal commitment procedures beyond his hypothetical maximum prison sentence. Jones v. United States, D.C.App., 411 A.2d 624 (1980). The government petitioned for rehearing en banc, disputing the determina[368]*368tion that the District of Columbia commitment scheme for insane criminals is punitive. Its petition was granted and the case was reheard by the en banc court. Since our previous opinions were vacated, we consider anew appellant’s equal protection claim and hold that he is not entitled to automatic release from St. Elizabeths upon the expiration of his hypothetical maximum prison sentence unless civil commitment proceedings are instituted by the government.
Appellant’s commitment resulted from a September 1975, charge of attempted petit larceny. He was first admitted to St. Eliza-beths because of a court-ordered competency examination.3 On March 12, 1976, on stipulated facts as to the crime and as to insanity, appellant was acquitted by the court of the charge by reason of insanity. On May 25, 1976, Judge James A. Washington held a “50-day release hearing” pursuant to D.C.Code 1973, § 24-301(d)(2)4 and continued appellant’s confinement at St. Elizabeths because of his failure to prove by a preponderance of the evidence that he. was no longer mentally ill or dangerous to himself and others.5 A further hearing was set for November 29, 1976. On that date, Judge Hamilton held a second hearing during which appellant raised the argument that his confinement under § 301(d) could not extend beyond his hypothetical maximum prison sentence and that he was therefore entitled to release. The court ordered the government to show cause why appellant should not be released or civilly committed under D.C.Code 1973, § 21-545(b). After a hearing in February of 1977, Judge Hamilton denied appellant’s motion for immediate release or, in the alternative, civil commitment, and continued his indefinite confinement at St. Eliza-beths. A timely appeal from this order was filed on February 28, 1977.6
Before analyzing appellant’s equal protection claim, we deem it necessary to reject any suggestion that confinement pursuant to subsection 301(d) is punitive in nature. We recognize that appellant never explicitly made such an assertion, but that implication underlies his argument (and certainly our prior opinions) that the length of the prison sentence which an acquittee might have received determines when he is entitled to release or civil commitment under Title 24 of the D.C.Code. We conclude that there is no basis for finding § 301(d) punitive in any respect.
This court’s decision in Bethea v. United States, D.C.App., 365 A.2d 64, 90 (1976), cert. denied, 433 U.S. 911, 97 S.Ct. 2979, 53 L.Ed.2d 1095 (1977), noted that “Congress struck a careful balance between the interest of the individual and those of the community,” in the enactment of the District of Columbia commitment scheme for persons acquitted by reason of insanity. The purpose behind this careful balance was explained in Hough v. United States, 106 U.S.App.D.C. 192, 195, 271 F.2d 458, 461 (1959), when Judge Bazelon stated that
[T]he basic policy underlying the statute ... as we read the legislative history, is to provide treatment and cure for the individual in a manner which affords reasonable assurance for the public safety. .. .
[369]*369More recent cases reiterate the dual purpose of § 301(d) as first, the treatment and recovery of the patient, and second, the protection of society and the patient. Collins v. Cameron, 126 U.S.App.D.C. 306, 308, 377 F.2d 945, 947 (1967); Overholser v. O’Beirne, 112 U.S.App.D.C. 267, 269, 302 F.2d 852, 854 (1961); Ragsdale v. Overholser, 108 U.S.App.D.C. 308, 312, 281 F.2d 943, 947 (1960). The 1970 amendments to § 301(d), enacted in response to the decision in Bolton v. Harris, 130 U.S.App.D.C. 1, 395 F.2d 642 (1968),7 have not altered its original purpose. See United States v. Jackson, 179 U.S.App.D.C. 375, 381, 553 F.2d 109, 115 (1976). Indeed, the Bolton decision inescapably leads to the conclusion of nonpuni-tiveness. This is because Bolton’s requirement of a separate judicial hearing before indeterminate commitment was intended to undo the punitive aspects attending the formerly automatic connection between the determination of guilt and the commitment of a defendant who pleaded insanity.
The exclusively remedial and protective goals of the statute demonstrate that a punitive rationale has no part in the commitment of persons acquitted by reason of insanity. We agree that
[i]n the light of [the legislative] purpose [of § 301], we must reject the District Court’s suggestion that appellant is a “prisoner.” Nothing in the history of the statute — and nothing in its language — indicates that an individual committed to a mental hospital after acquittal of a crime by reason of insanity is other than a patient. The individual is confined in the hospital for the purpose of treatment not punishment; and the length of confinement is governed solely by considerations of his condition and the public safety. Any preoccupation by the District Court with the need of punishment for crime is out of place in dealing with an individual who has been acquitted of the crime charged. [Hough v. United States, supra at 196, 271 F.2d at 462.]
Society may not excuse a defendant’s criminal behavior because of his insanity and at the same time punish him for invoking an insanity defense. This would nullify that defense, contrary to express legislative intent, see D.C.Code 1973, § 24-301(j) (establishing procedures for pleading insanity), and raise serious constitutional issues.
The regulatory nature of § 301(d) is also evidenced by the non-adversarial character of commitment decisions. All parties, including the government, the hospital8 and the acquittee assist in presenting the facts relevant to a determination of the proper conditions and treatment for the insanity acquittee. See United States v. Ecker, 177 U.S.App.D.C. 31, 45, 543 F.2d 178, 192 (1976), cert. denied, 429 U.S. 1063, 97 S.Ct. 788, 50 L.Ed.2d 779 (1977); Bolton v. Harris, supra at 12 n.64, 395 F.2d at 563 n.64; Lake v. Cameron, 124 U.S.App.D.C. 264, 268, 364 F.2d 657, 661 (1966) (en banc).
Furthermore, plain reason compels rejection of appellant’s reliance on his hypothetical maximum prison term as artificial and meaningless. Statutory maximum sentences have no relationship to the purposes of mental care and treatment. They are intended rather, to set the outer boundaries of lawful punishment for persons found criminally responsible for specified offenses. Not even convicted criminals are automatically sentenced to the maximum applicable term of incarceration. Subsection 301(d) commitments are neither expressly nor impliedly related to statutory maximum sentences. To the contrary, § 301(d) contemplates an indeterminate period of confinement and treatment, depending on when the patient has recovered his sanity or no [370]*370longer poses a danger to himself or others.9 As Dixon v. Jacobs, 138 U.S.App.D.C. 319, 325, 427 F.2d 589, 595 (1970) explains:
Confinement of the mentally ill rests upon a basis substantially different from that which supports confinement of those convicted of crime. In the latter case, with rare exceptions, the continuing validity of confinement rests solely on the validity of the initial commitment. Confinement of the mentally ill, however, depends not only upon the validity of the initial commitment but also upon the continuing status of the patient. Specifically, under our statutes, he must be released from the hospital if he is no longer mentally ill; if, although he remains mentally ill, he is no longer “likely to injure himself or other persons”; or, should the patient so desire, if a course of outpatient treatment can be fashioned that will adequately protect the interests both of the patient and the public. [Footnotes omitted.]
The notion that the duration of an acquit-tee’s hospitalization can be established by statute or court order ignores the most basic precepts of medicine and psychiatry. Unfortunately, the present state of the art makes it generally impossible to predict either the time required to rehabilitate a mental patient, if at all possible, or at what point he will cease to be a danger to himself or others. Only ongoing medical and psychiatric evaluation offer a realistic hope of such prognosis.10 Therefore, reference to either a hypothetical maximum prison sentence, or even to a judicially limited commitment term would completely refute the statutory purpose of § 301(d) and would frustrate any attempt at treating and rehabilitating mental patients who happen to have been acquitted of crimes by reason on insanity.
Our conclusion that § 301(d) is not punitive is supported by our recent decision in United States v. Edwards, D.C.App., 430 A.2d 1321 (Nos. 80-294 & 80-401, May 8, 1981) (en banc), where the contention that incarceration inevitably constitutes punishment was rejected. Though commitment of acquittees is in no sense incarceration, the principle that the penal character of a statute depends on its underlying nature and whether it is reasonably supported by a legitimate state interest, applies equally to the analysis of commitment statutes.11 [371]*371There is no evidence that the District of Columbia statutory scheme for commitment of insane criminals is anything but a regulatory, prophylactic statute, based on a legitimate governmental interest in protecting society and rehabilitating mental patients. Nor is § 301(d) rendered penal by the fact that it is predicated on the commission of a crime. Evidence of crime is only one of the elements triggering § 301(d) commitment, the other element being proof of insanity by a preponderance of the evidence. Since the crime is relevant only insofar as it indicates dangerousness, not evil or criminal responsibility, the presumption of continuing dangerousness, which is rebuttable by the acquittee, is both reasonable and valid.
Because we have no evidence in the record that the conditions of appellant’s confinement are punitive or that his particular commitment was based on punitive considerations, we must conclude that appellant’s detention is grounded on the legitimate nonpunitive interests of the District of Columbia.
Appellant challenges his confinement under § 301(d) as violative of equal protection of the laws. The due process guarantee of the Fifth Amendment of the United States Constitution, which is directly applicable to the District of Columbia, encompasses the right to equal protection. Bolling v. Sharpe, 347 U.S. 497, 74 S.Ct. 693, 98 L.Ed. 884 (1954); Matter of C.W.M., D.C.App., 407 A.2d 617, 625 (1979).
In the absence of specific objections to conditions of confinement or claims of inadequate or discriminatory treatment,12 the validity of appellant’s equal protection claim depends on whether the differences between the present § 301(d) commitment scheme and the involuntary committment scheme under § 545(b) of Title 21 are justifiable by reason of the situational differences between acquittees and committees.
Our analysis begins with the Supreme Court case of Baxstrom v. Herold, 383 U.S. 107, 86 S.Ct. 760, 15 L.Ed.2d 620 (1966), which held that equal protection requires that a prisoner to be transferred to a mental hospital be given the same procedural protections as those afforded other persons subject to involuntary civil commitment. Two years later, the United States Court of Appeals for the District of Columbia found that Baxstrom’s equal protection holding, as well as the due process guarantees of Specht v. Patterson, 386 U.S. 605, 87 S.Ct. 1209, 18 L.Ed.2d 326 (1967),13 require that “persons found not guilty by reason of insanity ... be given a judicial hearing with procedures substantially similar to those in civil commitment proceedings.” Bolton v. Harris, supra at 10, 395 F.2d at 651 (footnote omitted). Bolton was expressly premised on the weakness of the proof of a defendant’s insanity at the time of the offense; when Bolton was decided, the standard for acquittal was whether there was a reasonable doubt regarding past sanity. Id. at 8, 395 F.2d at 649. The 1970 amendments to § 301 have significantly narrowed this evidentiary gap by requiring that the defendant affirmatively prove his exculpating insanity to the jury by a preponderance of the evidence at the trial for his criminal offense. D.C.Code 1973, § 24-301(j).14 The [372]*372judicial hearing required by Bolton was codified in § 301(d)’s 50-day release hearing provision, notwithstanding the changed nature of the insanity defense.
The equal protection test suggested by these cases is that the procedures and standards of different commitment schemes be relevant to the classification and that any differences not be substantial. We therefore agree with the statement in United States v. Jackson, supra at 386, 553 F.2d at 120, that § 301(d) “must be upheld if there is a rational basis for the scheme it creates.” The court arrived at this conclusion by determining that neither Jackson v. Indiana, 406 U.S. 715, 92 S.Ct. 1845, 32 L.Ed.2d 435 (1972) (indeterminate pretrial commitment procedures found to violate equal protection), nor Baxstrom, supra, held that strict scrutiny applies to procedures used for the criminal commitment of mentally ill persons.15 In reviewing the petitioner’s argument in Baxstrom, Chief Justice Warren stated that “[e]qual protection does not require that all persons be dealt with identically, but it does require that a distinction made have some relevance to the purpose for which classification is made.” Baxstrom, supra, 383 U.S. at 111, 86 S.Ct. at 762. Bolton also recognized that “a reasonable application [of the equal protection doctrine] permits Subsection (d) to treat persons acquitted by reason of insanity differently from civilly committed persons to the extent that there are relevant differences between those two groups.” Bolton, supra at 10, 395 F.2d at 651. But substantial differences are prohibited under Bolton. Id. Thus, a reasonable distinction between the two statutory schemes would be one that is both relevant to the government’s legitimate interests in the separate classification and not impermissibly substantial.
Before reviewing the differences between § 24-301(d) and § 21 — 545(b), it is important to note their similarities. First, the substantive standard of commitment is identical under both statutes. The twofold proof requirement of mental illness and dangerousness varies only in the manner in which it is established.16 Second, both § 24-301(d)(2) and § 21-545(b) provide for mandatory judicial hearings, with notice and assistance of counsel (court-appointed if necessary). These common characteristics constitute the essential due process rights associated with involuntary commitment. See Vitek v. Jones, 445 U.S. 480, 100 S.Ct. 1254, 63 L.Ed.2d 552 (1980) (recognizing a prisoner’s due process rights to a hearing before transfer to a mental health facility); 17 Specht v. Patterson, supra.18 Thus [373]*373with respect to important constitutional protections the two statutes provide the same coverage.
As persuasively explained in our first panel opinion, the differences between the two procedures
can be justified by reference to situational differences between the two groups immediately prior to the respective hearings. The civil commitment question, as to any potential committee, is of first impression, whereas the “release hearing” procedure for an acquittee presumably can be somewhat abbreviated because of the predictive value of the initial determinations of insanity and dangerousness at the criminal trial. (That predictive value rests on the defendant’s own prior proof of his insanity by a preponderance of the evidence — by a jury trial if he requested it.) Whereas the § 24-545(b) hearing, therefore, represents a de novo process, the § 24-301(d) hearing is an updating process to determine how present mental status compares with earlier findings which had been urged by the defendant himself.... In either case, the only concern is a determination as to sanity and dangerousness, with a view to rehabilitation. Given these situational differences between acquittees and potential committees immediately prior to the initial commitment determination, the difference in hearing procedures is arguably justified; there is no constitutional prohibition against rational differences in the treatment of differently situated persons. [Jones v. United States, supra, 396 A.2d at 189.]
There appear to be three differences between § 24-301(d) and § 21-545(b) commitments: (1) the availability of jury trial, (2) the question of who carries the burden of proof, and (3) the amount of proof required to justify commitment.19 We review these distinctions individually to ascertain whether they are permissibly relevant or imper-missibly substantial under Baxstrom and Bolton.
While the jury trial right available to committees is not similarly available to an acquittee in a 50-day release hearing, this difference is justified by the fact that the acquittee has had a right to a jury determination of his sanity at the time of the offense.20 Thus the acquittee’s mental illness is initially established by affirmative proof.' Dangerousness is no less validly established by proof that the defendant committed the criminal act, a finding necessarily underlying any acquittal by reason of insanity. See Bethea, supra at 93-95; Smothers v. United States, D.C.App., 403 A.2d 306, 310 (1979). In United States v. Ecker, supra at 48, 543 F.2d at 195, the court stated that “[s]ince 1958 this court has consistently accepted the proposition that the dangerousness demonstrated by the commission of a crime and acquittal by reason of insanity constitutes a rational basis for the disparity in release provisions governing acquittees and committees.” (Footnote omitted). Ecker also recognized that some disparities in commitment proceedings are similarly permissible, id. at 49-50, 543 F.2d at 196-97, and explained that “[s]ubsection (d) patients are treated differently from civil committees because they are ‘an exceptional class of people’ who [374]*374have ‘already unhappily manifested the reality of anti-social conduct.’ ” Id. at 50, 543 F.2d at 197 (footnotes omitted).
The fact that appellant’s mental illness and dangerousness are not jury determined, but derived from a prior jury finding, is not significant since the continuation of these attributes is a rational and permissible evi-dentiary presumption.21 In Waite v. Jacobs, 154 U.S.App.D.C. 281, 288-89, 475 F.2d 392, 399-400 (1973), the validity of this presumption was recognized:
The rational justification for placing the burden of proof on a committee is that his mental illness and dangerousness have previously been convincingly established. In light of those established facts, the law gives effect to a presumption of continuity of status. It comports with normal perceptions of reality — and hence is rational — to assume that, once a given status is proven to exist, it continues to do so in the absence of evidence showing the contrary to be more likely than not.
In Waite, however, the presumption was not applicable because unlike in the instant case, the appellant had never been afforded a post-acquittal judicial hearing on the question of his continued mental illness and dangerousness.
The availability of a jury trial under § 21 — 545(b) and the absence of such a right at a § 24-301(d) hearing is also an insubstantial difference because the findings of mental illness and dangerousness are based on expert testimony and are not matters uniquely within the province of a jury of lay persons. In Addington v. Texas, 441 U.S. 418, 429, 99 S.Ct. 1804, 1811, 60 L.Ed.2d 323 (1979), the Court explained that in contrast to delinquency proceedings or criminal prosecutions where “the basic issue is a straightforward factual question — did the accused commit the act alleged,” the factual questions in a civil commitment proceeding “represent only the beginning of the inquiry.” The Court continued: “Whether the individual is mentally ill and dangerous to either himself or others and is in need of confined therapy turns on the meaning of the facts which must be interpreted by expert psychiatrists and psychologists.” Id. (emphasis in original). Thus, both judge and juror are forced to rely on expert evidence in commitment proceedings, significantly diminishing the importance of their personal judgment, values and experience. In sum, because (1) an acquittee has a right to a jury determination of past insanity at his criminal trial; (2) it is reasonable to presume the continuation of a mental illness; and (3) a jury right in commitment proceedings is not as meaningful as it is in ordinary criminal cases, the absence of a jury right at a § 24-301(d) release hearing is not a substantial difference vis-a-vis § 21-545(b) civil commitment.
The second distinction between the two commitment procedures in the District of Columbia is the fact that the government bears the burden of proof in a § 21-545(b) hearing, whereas in the 50-day release hearing, the acquittee must prove that he is no longer mentally ill or dangerous. It is entirely rational for the District to require an acquittee to prove his entitlement to release where he was the one to advocate the fact of his past insanity. Automatic § 301(d) commitment does not follow an acquittal by reason of insanity when the question of insanity is raised by the court or the prosecutor, rather than the defendant. United States v. Wright, 167 U.S.App.D.C. 309, 511 F.2d 1311 (1975). As mentioned above, the presumption that a mental condition continues is a reasonable one and it is also reasonable to require the person who raised the presumption to refute it by affirmative proof. Furthermore, whatever difference in risk allocation there might be between [375]*375the two statutes as a result of who bears the burden of proof is minimized by the fact that when the acquittee bears the burden, he need prove entitlement to release by only a preponderance of the evidence, the lowest standard of proof, whereas when the government bears the burden, it must prove insanity and dangerousness by a higher standard, namely that of clear and convincing evidence. In re Nelson, D.C.App., 408 A.2d 1233 (1979).
Yet this disparity in the level of proof by which mental illness and dangerousness are established under the two procedures, when not regarded as a counterbalance to the risk of non-persuasion, is another difference between § 24-301(d) and § 21-545(b) which must be justified as rationally related to the situational differences between acquittees and committees. An acquittee’s past insanity is proven by a preponderance of the evidence. His present insanity is determined by his failure to rebut, by a preponderance of the evidence, the presumption of continuing insanity. In contrast, a committee’s detention is based on clear and convincing evidence of mental illness and dangerousness. In re Nelson, supra.22 The difference between these two standards is justified by the fact that Congress determined that a defendant raising an insanity defense should not have to meet a higher burden on such a relatively difficult issue. However, when the District seeks to commit a person who is disputing the fact of insanity or dangerousness, it is reasonable that the risk of error be more heavily thrust upon the government. See Addington v. Texas, supra.
In Bolton, supra at 10 n.50, 395 F.2d at 651 n.50, and in United States v. Brown, 155 U.S.App.D.C. 402, 478 F.2d 606 (1973), the circuit court also recognized that a preponderance standard is enough to provide equal protection to acquittees.
Appellant has argued that a series of later Supreme Court and circuit court decisions based on an equal protection theory support his entitlement to release as of the expiration of his hypothetical maximum prison term. However, the cases cited by appellant are all distinguishable.
In Humphrey v. Cady, 405 U.S. 504, 92 S.Ct. 1048, 31 L.Ed.2d 394 (1972), a defendant convicted of contributing to the delinquency of a minor was committed to a “sex deviate facility” in a Wisconsin state prison in lieu of sentence. The statute authorizing such commitment provided an initial term equal to the maximum sentence the defendant could have received, and five-year renewals based on a judge-made finding of dangerousness. The statutory scheme in Humphrey clearly included an express punitive element evidenced by the limitation of the initial commitment term to a period corresponding to that applicable to those convicted.23
In the same term that it decided Humphrey, the Supreme Court held that indefinite confinement of a person charged with a crime and found incompetent to stand trial violated equal protection because the criminal charges were insufficient to prove either that the defendant was dangerous or that he required treatment. Jackson v. Indiana, supra. Jackson is inapposite to the instant case because Jackson was never tried for the crime with which he was charged. See United States v. Ecker, supra at 49-51, 543 F.2d at 196-98 (distinguishing Jackson for same reason in equal protection challenge to § 24-301(e)). Since his contin[376]*376ued detention was not based on any other evidentiary predicate of dangerousness, it therefore became invalid after “the reasonable period of time necessary to determine whether there is a substantial probability that [the person held] will attain [the] capacity [to stand trial] in the foreseeable future.” Id. 406 U.S. at 738, 92 S.Ct. at 1858.
Appellant’s reliance on the District of Columbia Circuit cases of Waite v. Jacobs, supra, and United States v. Brown, supra, is also unavailing.24 Waite was acquitted before the Bolton decision and therefore automatically committed after a finding of not guilty by reason of insanity without a judicial hearing on his continued mental illness and dangerousness, which was subsequently required by Bolton and codified in § 24-301(d)(2). Waite’s commitment was therefore invalid from the beginning and arguably justifiable only as penal detention. As such, it was limited to the applicable maximum sentence period.
Brown was a “post-Bolton, pre-1970 amendments” acquittee who challenged the burden of proof at his post-acquittal judicial hearing. The Court of Appeals in Brown upheld the preponderance standard applied, justifying the difference in the level of proof vis-a-vis the level of proof required in § 21-545(b) proceedings by the “meaningful elements of responsibility” which an acquittee may have. Insofar as this reasoning suggests a punitive element to § 301(d) we reject it as inconsistent with our finding that the commitment scheme for acquittees is not intended to attribute any guilt or imply any social indebtedness in the excuse of a criminal offense. Therefore, we need not follow the dicta in Brown that “[t]he extent of [the commitment] period [justified by a post-Bolton, pre-1970 amendments commitment] calls for sound discretion, would take into account, e. g., the nature of the crime (violent or not), nature of treatment given and response of the person, would generally not"
exceed five years, and should, of course, never exceed the maximum sentence for the offense, less mandatory release time.” Id. at 408, 478 F.2d at 612. As previously explained, the only factors relevant to release from a mental institution are the ac-quittee’s continued dangerousness and his need for treatment. Judicial limitations on the duration of confinement based on hypothetical prison terms or other arbitrary determinations of a maximum term of hospitalization, as suggested in Brown, have no relation to the purpose of the statute. In any event, the need for such limitations has been obviated by the enactment of the 1970 amendments to § 24-301.
For the foregoing reasons, the trial court’s order denying appellant’s right to immediate release or, in the alternative, civil commitment pursuant to D.C.Code 1973, § 21-545(b) is
Affirmed.