Defendant appeals his-sentences for two convictions of second degree murder in violation of Utah Code Ann. § 76-5-203 (Supp. 1989). He claims that application of the sentencing provisions of Utah Code Ann. § 77-35-21.5 (Supp.1988) (amended 1989; repealed effective July 1, 1990) to mentally ill defendants violates article I, section 7 of the Utah Constitution and that the trial court erred in sentencing him to the Utah State Prison instead of the Utah State Hospital. We affirm.
In April 1988, defendant pleaded guilty and mentally ill to two counts of murder in the second degree. Pursuant to section 77-35-21.5(1), an evidentiary hearing was held to determine whether defendant should be confined at the state prison or the state hospital for treatment. The court considered the testimony of several witnesses and found that while defendant had established' that he had a mental illness as defined by statute, he did not meet the other criteria required for commitment to the state hospital. The court thereafter sentenced defendant to two consecutive terms of five years to life to be served in the state prison.
Utah Code Ann. § 77-35-21.5(4) (Supp.1988), the provision at issue, states in pertinent part:
(4) The court shall in its sentence order hospitalization at the Utah State Hospital or other suitable facility if, upon completion of the hearing and consideration of the record, the court finds by clear and convincing evidence that:
(a) the defendant has a mental illness as defined by Subsection 76-2-305(4);
(b) because of his mental illness the defendant poses an immediate physical *29danger to others or self, which may include jeopardizing his own or others’ safety, health, or welfare if placed in a correctional or probation setting, or lacks the ability to provide the basic necessities of life, such as food, clothing, and shelter, if placed on probation;
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(e) the Utah State Hospital or other suitable facility can provide the defendant with treatment, care, and custody that is adequate and appropriate to the defendant’s conditions and needs.1
Defendant’s initial contention on appeal is that the application of section 77-35-21.-5(4)(b) to mentally ill defendants violates due process of law under Utah’s constitution. Defendant, however, did not raise this issue below. Therefore, he “cannot assert it as a basis of error on appeal.”2 This is so even though defendant’s claim involves a constitutional right.3 And while the Court may nevertheless choose to consider a claim raised for the first time on appeal,4 we do not find it appropriate to do so here.5 Neither is this a case where the plain error rule is applicable. The criteria which give rise to the application of the doctrine but which are lacking here is twofold. The error must be obvious (“plain”), and it must be harmful.6
Defendant supports his claim of plain error upon this Court’s decision in State v. Copeland,7 which ruled that application of subsections (c) and (d) of section 77-35-21.5 to mentally ill criminal defendants violates due process under Utah’s constitution. Copeland was decided on December 8, 1988. However, the sentencing hearing in this case (at which subsection (b) was considered) occurred prior thereto on June 14 and 15, 1988. In essence, then, defendant’s plain error claim is that the trial court should have recognized the unconstitutionality of subsection (b) at least in part based upon the rationale offered against other subsections of the statute in a case decided almost six months after the trial court held its hearing on this matter. This contention is thus without merit.
Defendant next claims that the court erred in sentencing him to the state prison instead of the state hospital. Specifically, he asserts that the court erred in (1) “excluding all personality disorders from the definition of mental illness” under subsection (a); (2) concluding under subsection (b) that there was insufficient evidence to find that defendant poses any immediate physical danger to others or himself if placed in a correctional setting; and (3) misinterpreting subsection (e) in sentencing defendant to the state prison.
Utah Code Ann. § 76-2-305(4) (Supp. 1989) defines mental illness for the purposes of the statute at issue as
a mental disease or defect. A mental defect may be a congenital condition or one the result of injury or a residual effect of a physical or mental disease. Mental illness does not mean a personality or character disorder or abnormality manifested only by repeated criminal conduct.
Subsection -305(3) of the statute also provides in part:
A person who is under the influence of voluntarily consumed or injected alcohol, controlled substances, or volatile substances at the time of the alleged offense is not excused from criminal responsibility on the basis of mental illness.
In its findings of fact and conclusions of law, the trial court stated:
*302. With regard to subsection (a) of Section 77-35-21.5(4), the Court finds that the defendant is mildly to moderately mentally retarded. Further, that mental retardation is a mental defect as defined in Section 76-2-305(4) and that therefore the defendant has a statutory mental illness.
3. The Court finds that the defendant has several personality disorders and tends to abuse drugs and alcohol, conditions which do not constitute mental illness as defined by Section 76-2-305(4).
4. The Court further finds that the defendant has no mental illnesses as defined in [Section] 76-2-305(4) other than the mental retardation described in paragraph 2 above.
Defendant contends that the court erred in failing to consider his personality disorders as mental illnesses under subsection (a). Specifically, he surmises that the court concluded that the phrase in subsection 76-2-305(4) “manifested only by repeated criminal conduct” modified only the term “abnormality” and that this provision thus excludes all personality and character disorders from the definition of mental illness. Defendant urges the determination that the court erred in not concluding that he was mentally ill as a result of his personality disorders in addition to the conclusion that he is mentally ill since he suffers from mental defects.
Even assuming, however, that defendant’s claim is accurate8 and that the court could have properly found in reference to subsection (a) that defendant was mentally ill based upon additional grounds, any error that occurred was harmless. The doctors from the state hospital agreed with the court’s finding that the state hospital was not the appropriate place to confine defendant, and given the fact that defendant has not otherwise shown that the trial court erred in concluding that he was not an appropriate candidate for hospitalization under subsections 77-35-21.-5(4)(b) and (e) in that he did not pose an immediate physical danger to others or to himself and that the hospital could provide “custody that is adequate and appropriate to the defendant’s conditions and needs,” we cannot conclude that any error is substantial and prejudicial such that there is a reasonable likelihood that in its absence there would have been a more favorable result for defendant.9 Thus, defendant’s claim is without merit.
Defendant’s claim that the court erred in concluding that he was not in immediate physical danger to others or to himself if placed in a correctional or probation setting is similarly without merit. The trial court heard testimony on the issue of whether, based upon his mental illnesses, defendant would be in any immediate physical danger if placed at the state prison. Two doctors testifying for the defense expressed concern regarding defendant’s prison incarceration and the fact that they considered defendant to have a “dependent personality” which may make him easily led and abused by others. In contrast, several doctors from the state hospital testified that defendant was not an appropriate candidate for confinement at that institution. And two correctional officers testified that defendant was a model inmate during incarceration in the county jail. In sum, the trial court had before it significant evidence to demonstrate that because of his mental illness defendant posed no “immediate physical danger” to himself or others if confined in prison. Instead, the court specifically found that defendant would not pose an immediate danger and that he would be able to function at the state prison based upon evidence adduced with regard to his past incarceration and present confinement in the Salt Lake County Jail. There is no indication that these findings are clearly erroneous.
Finally, the trial court concluded under subsection (e) of section 77-35-21.5(4):
[T]he Utah State Hospital is not a suitable facility for providing the defendant *31with the treatment, care and custody that is adequate and appropriate to the defendant’s conditions and needs, because no therapies are available to treat the defendant’s problem of retardation which is permanent. Further, that the Utah State Hospital cannot provide the secure custody necessary for the defendant who stands convicted of two homicides in Salt Lake County, is awaiting sentencing in Davis County on a subsequent Second Degree Homicide, and who tends to abuse drugs and/or alcohol.
Defendant contends that this finding was erroneous because (1) the trial court interpreted subsection (e) as requiring that the mental illness must be completely curable in order to qualify the patient for sentencing to the hospital; (2) the hospital is able to treat defendant’s personality disorders; (3) subsection (e) does not require the court to choose between sentencing defendant to the hospital or the prison; and (4) there is no statutory basis for the court’s consideration of the danger posed by defendant in the state hospital. We need not address defendant’s contentions since there is no evidence that the trial court erred in concluding that the state hospital could not adequately provide for defendant’s custody as expressly required by statute. As we noted in Copeland, “[I]f neither the hospital nor any other facility can provide ‘treatment, care, and custody that is adequate and appropriate to the defendant’s conditions and needs,’ placement in such a facility may not be justified because of the additional security burdens it would impose.” 10 The evidence supports the trial court’s finding that the hospital was not the appropriate place, given defendant’s custody concerns. Therefore, the trial court did not err in so concluding.
We have reviewed defendant’s other claims and find them to be without merit. The judgment and sentences are affirmed.
HOWE, Associate C.J., and ZIMMERMAN, J., concur.. Subsections (4)(c) and (4)(d) of this statute were found unconstitutional in State v. Copeland, 765 P.2d 1266, 1272 (Utah 1988).
. State v. Van Matre, 777 P.2d 459, 463 (Utah 1989) (citation omitted).
. See id. (due process violation claimed); State v. Pierce, 655 P.2d 676, 677 (Utah 1982) (per curiam) (violation of right against self-incrimination claimed).
. Pierce, 655 P.2d at 677.
. See Copeland, 765 P.2d at 1272.
. Utah R.Evid. 103(d); see State v. Eldredge, 773 P.2d 29 (Utah 1989); State v. Verde, 770 P.2d 116 (Utah 1989).
. 765 P.2d 1266.
. See generally State v. Murphy, 760 P.2d 280, 284-85 (Utah 1988) (discussion of distinctions between mental illness and mental retardation).
. State v. Tillman, 750 P.2d 546, 555 (Utah 1987).
. 765 P.2d at 1272 (quoting § 77-35-21.5(4)(e)).