We granted certiorari in People v. Waits, 695 P.2d 1176 (Colo.App.1984), to consider three issues: (1) whether two guilty pleas entered by the defendant, Jimmy L. Waits, met the requirements of Crim.P. 11 and due process of law; (2) whether attempted felony murder is a valid offense, and if not, whether Waits’s guilty plea to attempted felony murder extinguishes his due process right to be advised of the nature of the offense; and (3) whether, given that Waits entered his guilty plea following a suppression ruling by this court that we later overruled, Waits’s guilty pleas were knowingly, intelligently, and voluntarily entered. We decide that the Crim.P. 11 advisement on attempted felony murder was inadequate and therefore vacate the plea to that charge. The guilty plea to second degree burglary, however, met the requirements of Crim.P. 11 and due process and was knowingly, intelligently, and voluntarily entered based on the applicable law concerning searches at the time of the plea. Finally, we determine that the People may retain the present sentence for the burglary plea or may retry the defendant on the attempted murder charge, in which case the entire plea package is vacated. We therefore reverse in part and affirm in part the judgment of the court of appeals.
I.
On February 15,1977, the defendant was charged with second degree burglary under section 18-4-203, 8 C.R.S. (1978), after *1331police officers found in the defendant’s car objects reported stolen from a home a few days earlier. The district court suppressed the evidence found in the car because the court determined that the defendant’s action to evade the police officers did not justify the officers’ subsequent investigatory stop and search of the car. In the People’s interlocutory appeal in People v. Waits, 196 Colo. 35, 580 P.2d 391 (1978), this court reversed the suppression order, ruling that the defendant’s evasive maneuvers gave rise to a reasonable suspicion of criminal activity sufficient to support an investigatory stop.
On December 18, 1978, the defendant was charged with attempted first degree murder under section 18-2-101, 8 C.R.S. (1978), based on evidence that during the night of December 15, 1978, after the victim found the defendant standing in the victim’s living room, the defendant stabbed the victim a number of times. The victim escaped and ultimately recovered from the stab wounds; the defendant was arrested inside the victim’s home. The December 18, 1978, information included two habitual criminal counts. § 16-13-101(1), 8 C.R.S. (1978).1
On January 30, 1979, after this court’s reversal of the suppression order in the burglary case, the defendant pleaded guilty to attempted first degree murder, second degree burglary, and the habitual criminal charges. At the advisement the defendant stated that he understood the elements of attempted first degree murder and second degree burglary and that he was the person convicted of two prior felonies in New Mexico. The court sentenced him to two concurrent prison terms of twenty-five to fifty years, and other charges pending against him were dismissed.2
On November 3, 1980, the defendant filed a Crim.P. 35(c) motion asserting that the district court had failed to comply with Crim.P. 11 because its explanation of the elements of first degree murder and second degree burglary was inadequate. At the hearing on his motion, the defendant testified that he did not know during the advisement whether he was pleading guilty to attempted murder or murder or what the elements of burglary were. The district court denied the defendant’s Crim.P. 35(c) motion, ruling that the defendant stated during the advisement that he understood the nature of the charge, that the advising court3 explained to the defendant what criminal attempt meant, that the court satisfactorily explained the elements of burglary, and that the defendant had past experiences with court eases involving burglary.
Prior to oral argument in the court of appeals on the defendant’s Crim.P. 35(c) claim, this court, in People v. Thomas, 660 P.2d 1272 (Colo.1983), overruled People v. Waits, 196 Colo. 35, 580 P.2d 391. In Thomas, 660 P.2d at 1277, we held that efforts to avoid police contact, by themselves, are insufficient to provide a reasonable suspicion for an investigative stop. Based on Thomas, the defendant requested remand of his appeal to allow the district court to consider whether his guilty pleas, entered after an allegedly erroneous ruling upholding the seizure of evidence, were knowing, intelligent, and voluntary. On remand, the district court ruled that a defendant who pleads guilty waives his right to challenge illegally seized evidence.
The court of appeals affirmed the district court’s rulings on the ground that because the defendant received a substantial benefit4 by pleading guilty to attempted first *1332degree murder and second degree burglary, a denial of postconviction relief was proper. Noting that a coherent advisement of the elements of attempted felony murder would be impossible, the court of appeals determined that the district court’s discussion of the range of penalties facing the defendant based on his plea and the defendant’s agreement to those penalties barred a challenge to the advisement. The court of appeals ruled also that the district court adequately explained the nature and elements of second degree burglary given the defendant’s previous experience in pleading guilty to burglary charges. Finally, the court of appeals agreed with the district court that the defendant’s guilty plea to burglary waived his right to collaterally attack the suppression issue.
II.
The defendant asserts that his guilty pleas to attempted first degree murder and second degree burglary were entered in violation of Crim.P. 11 and due process of law because the advisement concerning attempted first degree murder was nonsensical and because the advisement concerning second degree burglary failed to define and explain the terms “intent,” “specific intent,” and “theft.” Due process requires that a court accept a guilty plea only when it has ascertained that the plea is voluntary, knowing, and intelligent. See Boykin v. Alabama, 395 U.S. 238, 89 S.Ct. 1709, 23 L.Ed.2d 274 (1969); People v. Cabral, 698 P.2d 234 (Colo.1985); Harshfield v. People, 697 P.2d 391, 393 (Colo.1985); People v. Leonard, 673 P.2d 37, 39 (Colo.1983); see also People v. Mozee, 723 P.2d 117, 121-22 n. 4 (Colo.1986) (court adopts formulation that valid waiver of rights must be made voluntarily, knowingly, and intelligently; court also inquires whether waiver was intentional because court previously has used various combinations of the terms “knowingly,” “voluntarily,” “intelligently,” and “intentionally” to determine the validity of waiver).
Crim.P. 11, which contains the procedure for taking guilty pleas in accordance with constitutional requirements, Leonard, 673 P.2d at 39-40, provides in pertinent part:
(b) The court shall not accept a plea of guilty or a plea of nolo contendere without first determining that the defendant has been advised of all the rights set forth in Rule 5(a)(2) and also determining:
(1) That the defendant understands the nature of the charge and the elements of the offense to which he is pleading and the effect of his plea....
In meeting the requirements of Crim.P. 11, we have not required courts to proceed in a formulaic manner, see Wilson v. People, 708 P.2d 792 (Colo.1985), but have held instead that the explanation necessary depends on the nature and complexity of the crime. Cabral, 698 P.2d 234; Wright v. People, 690 P.2d 1257, 1261 (Colo.1984). However, the record must show that the defendant understood the critical elements, including the intent requirement, of the crime to which the plea is tendered. Wilson, 708 P.2d 792; Cabral, 698 P.2d 234; Watkins v. People, 655 P.2d 834 (Colo.1983).
A.
The district court gave the following attempted first degree murder advisement:
Q. In Case CR-11604, in Count 1, Mr. Waits, you are charged that on the 15th day of December, at the City and County of Denver, State of Colorado, Jimmy L. Waits, that is you, did unlawfully and feloniously attempt to commit the crime of First Degree Murder, which is a Class 1 felony, against [the victim] and did engage in conduct constituting a substantial step toward the commission of said crime, as defined by 18-3-102, C.R.S. 1973, as amended; contrary to the form of the statute in such case made and provided, and against the peace and dignity of the People of the State of Colorado.
Do you understand the nature of the charge?
A. Yes.
*1333Q. You understand that the elements of First Degree Murder are that you, acting either alone or with one or more persons, committed or attempted to commit, and in the course of or furtherance of the crime that he is committing or attempting to [commit], or of immediate flight therefrom, the death of a person, other than than one of the participants, is caused.
You understand that the elements— those are the elements of murder, and the District Attorney would have to prove all the elements of the offense beyond a reasonable doubt.
Do you have any questions about those elements, sir?
A. No, sir.
(Emphasis added.) Later, in explaining the elements of criminal attempt in connection with first degree murder, the court noted that
the substantial step, Mr. Waits, means any conduct, whether act, omission, or possession, which is strongly corroborative of the firmness of the actor’s purpose to complete the commission of the offense. Now, I think the definition is probably more complicated—
[[Image here]]
It shows, Mr. Waits, that you were serious about what you started to do.
It is unclear from either the information or the advisement whether the defendant was charged with attempted murder with deliberation, attempted felony murder, or attempted extreme indifference murder. The People assert that the charge of attempted first degree murder involved a charge of attempted felony murder. A person commits the crime of felony murder if
[a]cting either alone or with one or more persons, he commits or attempts to commit arson, robbery, burglary, kidnapping, sexual assault in the first degree or second degree as prohibited by section 18-3-402 or 18-3-403, or a class 3 felony for sexual assault on a child as provided in section 18-3-405(2), and, in the course of or in furtherance of the crime that he is committing or attempting to commit, or of immediate flight therefrom, the death of a person, other than one of the participants, is caused by anyone.
§ 18-3-102(1)(b), 8 C.R.S. (1978). Specific intent is not required for felony murder. People v. Scheer, 184 Colo. 15, 518 P.2d 833 (1974). A person commits criminal attempt if
acting with the kind of culpability otherwise required for commission of an offense, he engages in conduct constituting a substantial step toward the commission of the offense. A substantial step is any conduct, whether act, omission, or possession, which is strongly corroborative of the firmness of the actor’s purpose to complete the commission of the offense.
§ 18-2-101(1), 8 C.R.S. (1978). An essential element of criminal attempt is that the defendant act knowingly with respect to the underlying offense. People v. Krovarz, 697 P.2d 378 (Colo.1985).5
Here, the district court mislabeled the attempted murder charge as that of first degree murder numerous times and gave an incomprehensible description of the elements of attempted first degree murder. Therefore, the advisement concerning attempted first degree murder did not meet the requirements of Crim.P. 11, *1334and we vacate the defendant’s guilty plea to attempted first degree murder.
B.
The defendant also asserts that the advisement concerning second degree burglary was deficient because the district court did not explain the terms “intent,” “specific intent,” and “theft.” Section 18-4-203(1), 8 C.R.S. (1978), provides that “[a] person commits second degree burglary, if he knowingly breaks an entrance into, or enters, or remains unlawfully in a building or occupied structure with intent to commit therein a crime against a person or property.” Second degree burglary requires specific intent and actual constructive trespass. People v. Diaz, 182 Colo. 369, 513 P.2d 444 (1973); People v. Archuleta, 180 Colo. 156, 503 P.2d 346 (1972).
Initially, the district court advised the defendant concerning second degree burglary as follows:
Q. Now, in Case No. 8362, it’s charged that on the 11th day of February, 1977, at the City and County of Denver, State of Colorado, Jimmy Lee Waits, did unlawfully, feloniously and knowingly break an entrance into and enter and remain unlawfully in [a] dwelling ... with the intent to commit therein the crime of theft....
[[Image here]]
Q. (By the Court) Now, second degree burglary, Mr. Waits, is — the elements are as follows:
That knowingly breaking and entering into or entering or remaining unlawfully in a dwelling or building or occupied structure, other than a dwelling, with the specific intent to commit the crime or crimes against person or property, a crime other than trespass.
Do you understand the elements of that offense?
A. Yes.
Later, after the prosecutor reminded the court to break down the elements of the crime and explain each one, the court stated:
Q. (By the Court) On Case No. 8362, Mr. Waits, the first count reads that on the 11th day of February, 1977, at the City and County of Denver, Jimmy Lee Waits did unlawfully, feloniously and knowingly break an entrance into and enter and remain unlawfully.
Now, the Court — the District Attorney, if this matter went to trial, would have to prove, first of all, that on the 11th day of February, — he would have to prove the date and place. That the offense occurred in the City and County of Denver. That you did unlawfully, which means against the law, feloniously, which also means it was against the law, and knowingly, which means that you knew what you were doing, and that you deliberately did it, break an entrance, which means that you didn’t have the right to break into and enter and remain unlawfully in the dwelling ... with the intent therein to commit the crime of theft, and this means that you did not have the consent of [the victim] to be at that place, and that you went in there with the intent to commit that kind of a crime. Either stealing something against the peace and dignity of the State of Colorado.
Those are the things that the District Attorney would have to prove beyond a reasonable doubt to a jury. And by entering a plea of guilty, of course, you are waiving those rights.
While the district court did not define the terms “intent,” “specific intent,” and “theft,” the court correctly noted that second degree burglary required specific intent to commit a crime against person or property, in this case theft,6 and that the offense must be committed knowingly. *1335For a crime of the complexity of second degree burglary, this is sufficient to meet the requirements of Crim.P. 11 and due process. See Wilson, 708 P.2d 792; People v. Adrian, 701 P.2d 45 (Colo.1985); cf. Harshfield, 697 P.2d 391 (Crim.P. 11 requirements not met because court failed to discuss mens rea requirement for breaking and entering a motor vehicle); Leonard, 673 P.2d 37 (court’s specific questions and comments concerning the elements of and factual basis for conspiracy to commit burglary and attempt to commit theft met requirements of Crim.P. 11). We therefore reject the defendant’s Crim.P. 35(c) challenge to his guilty plea to second degree burglary.
III.
The defendant also asserts that his guilty pleas were not knowingly, intelligently, and voluntarily entered because they were entered after an erroneous ruling of this court. Prior to the defendant’s guilty plea, this court reversed the district court’s suppression order concerning the objects found in the defendant’s car, finding that the defendant’s evasive maneuvers established sufficient reasonable suspicion by police officers to support an investigatory stop. People v. Waits, 196 Colo. 35, 580 P.2d 391 (1978). However, in People v. Thomas, 660 P.2d 1272, 1277 (Colo.1983), we expressly overruled the Waits holding “that action which does not amount to illegal conduct but is taken simply to avoid police contact is sufficient to support an investigative stop.” The fact that we overruled Waits after the defendant pleaded guilty, however, does not make Waits an erroneous ruling that renders the defendant’s guilty pleas not knowingly, intelligently, and voluntarily entered. Rather, existing cases are considered to be the law until they are overruled. See United States v. Peltier, 422 U.S. 531, 535, 542, 95 S.Ct. 2313, 2316, 2320, 45 L.Ed.2d 374 (1975).
While we determine that a defendant may not attack a guilty plea on the basis that the law later changed, there remains the question whether Thomas should be applied retrospectively to require suppression of the objects found in the defendant’s car and therefore invalidation of his guilty pleas. This court has followed the lead of the United States Supreme Court in determining the retrospectivity of a rule of criminal procedure, but on fourth amendment questions we have not chosen between the retrospectivity analysis set forth in Stovall v. Denno, 388 U.S. 293, 87 S.Ct. 1967, 18 L.Ed.2d 1199 (1967), and the “bright line” approach announced later in United States v. Johnson, 457 U.S. 537, 102 S.Ct. 2579, 73 L.Ed.2d 202 (1982). People v. Timmons, 690 P.2d 213, 215-16 (Colo.1984). In Stovall, 388 U.S. at 297, 87 S.Ct. at 1970, the Court considered “(a) the purpose to be served by the new standards, (b) the extent of the reliance by law enforcement authorities on the old standards, and (c) the effect on the administration of justice of a retroactive application of the new standards.” See also People v. Walker, 666 P.2d 113 (Colo.1983). In Johnson, 457 U.S. at 562, 102 S.Ct. at 2593, the Court held that, except for cases clearly controlled by existing retrospectivity precedent, decisions construing the fourth amendment would be applied retrospectively to all convictions not yet final at the time the decision was rendered.
In Johnson, 457 U.S. at 562, 102 S.Ct. at 2593, however, the Court expressly refused to address the retrospective reach of fourth amendment decisions to cases, such as this one, that involve collateral attacks, and while Stovall, 388 U.S. at 296, 87 S.Ct. at 1969, involved a collateral attack, the case did not involve a fourth amendment challenge.7 The United States Supreme Court *1336has since held that the Johnson analysis is also applicable to cases on direct appeal review involving the fifth amendment, Shea v. Louisiana, 470 U.S. 51, 54-58, 105 S.Ct. 1065, 1068-70, 84 L.Ed.2d 38 (1985), and that the Stovall factors apply to collateral attacks involving fifth amendment issues, Solem v. Stumes, 465 U.S. 638, 104 S.Ct. 1338, 79 L.Ed.2d 579 (1984), but the Court has not addressed specifically the retrospectivity analysis to be applied to collateral attacks involving fourth amendment issues.
Neither the Stovall analysis nor the Johnson analysis, however, leads us to conclude that Thomas should be applied retrospectively. In applying Stovall, we first look at the purpose of the rule in Thomas that furtive gestures alone may not be the basis for an investigative stop. Thomas focused on the protection of personal security and privacy from arbitrary and abusive police practices. This purpose, while important, is less significant than whether the new rule in Thomas enhances the reliability of the fact finding process and whether violation of the rule produces an unfair trial. See Adams v. Illinois, 405 U.S. 278, 92 S.Ct. 916, 31 L.Ed.2d 202 (1972); Stovall, 388 U.S. at 298, 87 S.Ct. at 1970. While violation of the rule may contribute to an unfair trial, enhancing trial reliability is a matter of degree and a failure to observe a newly established rule does not always result in inaccuracies and unfairness. Solem, 465 U.S. at 644, 104 S.Ct. at 1342. The counterváiling consideration of the disruption that would be caused by retrospective application of Thomas, in this case and in others, persuades us that Thomas should not be applied retrospectively.
Even if this case involved direct review, Johnson, 457 U.S. at 549-51, 102 S.Ct. at 2586-87, suggests that courts should not apply a “new” fourth amendment rule retrospectively when the rule is “an entirely new and unanticipated principle of law.” No new fourth amendment principle marking a clear break with the past has been applied retrospectively. United States v. Leon, 468 U.S. 897, 912-13, 104 S.Ct. 3430, -, 82 L.Ed.2d 702 (1984). In Johnson, 457 U.S. at 549-551, 102 S.Ct. at 2586-87, the court noted that a clear break with the past occurs when a decision explicitly overrules a past precedent. In cases such as Thomas where an express overruling of prior precedent occurred, the third Stovall factor — the effect on the administration of justice of a retrospective application of the new rule — militates in favor of applying the new rule prospectively only.8 See Desist v. United States, 394 U.S. 244, 250, 89 S.Ct. 1030, 1034, 22 L.Ed.2d 248 (1969).
The analysis in United States v. Peltier, 422 U.S. 531, 95 S.Ct. 2313, 45 L.Ed.2d 374, although it involved a direct appeal, supports our conclusion that Thomas should not be applied retrospectively. The court in Peltier refused to require retrospective application of Almeida-Sanchez v. United States, 413 U.S. 266, 93 S.Ct. 2535, 37 L.Ed.2d 596 (1973), which invalidated war-rantless automobile searches without probable cause, in part because retrospective application did not serve the exclusionary rule’s underlying policies, deterring unconstitutional searches and preserving judicial integrity. The fact that this is a collateral attack on the guilty pleas under Crim.P. 35(c) serves as an additional reason not to apply Thomas retrospectively because such a retrospective application would severely burden the administration of justice. Shea, 470 U.S. at-, 105 S.Ct. at-; see also Stovall, 388 U.S. at 299-300, 87 S.Ct. at 1971.
Having determined that Thomas is not to be applied retrospectively, we reject the *1337defendant’s assertion that his pleas were not made knowingly, intelligently, or voluntarily because they were based on our ruling in Waits, which was the then-applicable law.
Even if we were to apply Thomas retrospectively, in this case by pleading guilty the defendant waived any argument about illegally seized evidence. The general rule is that a defendant who pleads guilty is precluded from attacking his plea on the ground that evidence was seized in an illegal search and seizure unless a right to challenge the plea is preserved by statute. E.g., Lefkowitz v. Newsome, 420 U.S. 283, 288, 95 S.Ct. 886, 889, 43 L.Ed.2d 196 (1975); Von Pickrell v. People, 163 Colo. 591, 431 P.2d 1003 (1967); People v. Vina, 47 A.D.2d 895, 367 N.Y.S.2d 268 (N.Y.App.Div.1975) (statute preserves review of denial of suppression after guilty plea); People v. Miller, 33 Cal.3d 545, 658 P.2d 1320, 189 Cal.Rptr. 519 (1983) (statute preserves right to challenge guilty plea on appeal after trial court’s denial of suppression motion); J. Bond, Plea Bargaining & Guilty Pleas § 7.21(a)-(g), at 7-68 to 7-77 (2d ed. 1982); 3 W. LaFave, Search and Seizure: A Treatise on the Fourth Amendment § 11.1(d), at 487-94 (1978).
In McMann v. Richardson, 397 U.S. 759, 90 S.Ct. 1441, 25 L.Ed.2d 763 (1970), Parker v. North Carolina, 397 U.S. 790, 90 S.Ct. 1458, 25 L.Ed.2d 785 (1970), and Brady v. United States, 397 U.S. 742, 90 S.Ct. 1463, 25 L.Ed.2d 747 (1970) (the Brady trilogy), the United States Supreme Court upheld the validity of guilty pleas that were induced by the prospect that a coerced confession would be used at trial and that an unconstitutional death penalty would be imposed following a trial. The Court upheld the guilty pleas because the defendants had been competently counseled by an attorney before deciding to plead guilty. McMann, 397 U.S. at 772, 90 S.Ct. at 1449; Parker, 397 U.S. at 794-98, 90 S.Ct. at 1460-62; Brady, 397 U.S. at 749-58, 90 S.Ct. at 1469-74.9 Commentators have criticized the Brady trilogy as undermining a waiver theory that requires the intentional relinquishment or abandonment of rights and weakening the deterrence function of the exclusionary rule because law enforcement officials know that many cases will result in plea bargains. See Alschuler, The Supreme Court, The Defense Attorney, and The Guilty Plea, 47 U.Colo.L.Rev. 1, 35-41 (1975); Tigar, The Supreme Court; 1969 Term: Forward: Waiver of Constitutional Rights: Disquiet in the Citadel, 84 Harv.L.Rev. 1, 19-25 (1970); Note, The Guilty Plea As A Waiver of “Present But Unknowable” Constitutional Rights: The Aftermath of the Brady Trilogy, 74 Colum.L.Rev. 1435 (1974); cf. Note, Conditional Guilty Pleas, 93 Harv.L.Rev. 564 (1980) (allowing conditional guilty plea in order to preserve constitutional claims for appeal is sound judicial policy and constitutionally compelled). Despite the criticism of the Brady trilogy and the fact that none of the Brady trilogy cases concern the possible use of illegally seized evidence, it makes sense to preclude the defendant’s collateral attack on his guilty pleas in this case because even had the evidence been seized illegally, the constitutional infirmity merely weakens the state’s case, an impact on the guilty plea that is hard to measure. See Note, supra, 74 Colum.L.Rev. at 1459-60. We therefore find no reason in the facts of this ease to depart from the general rule that by pleading guilty the defendant waived the right to challenge his plea on the basis of an illegal search and seizure.
IY.
The defendant argues that if his guilty plea to attempted felony murder is vacated *1338his plea to second degree burglary must also be vacated because the two pleas were part of a plea package. People v. Miller, 33 Cal.3d 545, 658 P.2d 1320, 189 Cal.Rptr. 519 (1983); People v. Hill, 12 Cal.3d 731, 528 P.2d 1, 29, 30, 117 Cal.Rptr. 393 (1974), rev’d on other grounds, People v. De-Vaughn, 18 Cal.3d 889, 558 P.2d 872, 875 n. 5, 135 Cal.Rptr. 786 (1977). Both Miller and Hill noted that exclusion of the illegally obtained evidence on which the defendants’ pleas rested would cumulatively weaken the state’s case.
In this case, the failure properly to advise the defendant concerning attempted first degree murder under Crim.P. 11, unlike the exclusion of illegally obtained evidence in Miller and Hill, does not cumulatively weaken the state’s case against the defendant and there is no reason to invalidate the plea to second degree burglary. In the context of two guilty pleas that resulted in consecutive sentences, we have previously invalidated one plea and upheld the other. People v. Cabral, 698 P.2d 234 (Colo.1985). Although invalidation of the guilty plea to attempted first degree murder does not shorten the defendant’s sentence because the sentences are concurrent, invalidation of one conviction is not a hollow victory because that conviction may not be used for habitual criminal purposes. Cf. People v. Muniz, 667 P.2d 1377 (Colo.1983) (defendant has standing to challenge conviction after sentence is served since conviction may be basis of future habitual criminal charge). Here, the defendant receives the benefit of his guilty plea to second degree burglary because he was sentenced to twenty-five to fifty years as he agreed. As long as the People do not reinstate the other charges, the defendant has no basis for claiming that there has been a broken plea agreement. See Westen & Westen, A Constitutional Law of Remedies for Broken Plea Bargains, 66 Calif.L.Rev. 471, 507-08 (1978).
Ordinarily the People may reinstate the charges when a guilty plea is vacated, see People v. Colosacco, 177 Colo. 219, 493 P.2d 650 (1972), and a defendant may withdraw a guilty plea if a court does not agree with the plea bargain. See People v. Wright, 194 Colo. 448, 573 P.2d 551 (1978); see also Santobello v. New York, 404 U.S. 257, 92 S.Ct. 495, 30 L.Ed.2d 427 (1971); 3 ABA, Standards for Criminal Justice, Pleas of Guilty, Standard 14-3.3(g) commentary, at 14.88-14.89 (1979). Nevertheless, if the People reinstate the attempted first degree murder charge or any of the other charges, then both the guilty plea to attempted first degree murder and the guilty plea to second degree burglary should be vacated because retrying the defendant on fewer than all the charges would violate the plea agreement, which required two concurrent sentences of twenty-five to fifty years and dismissal of the other charges. The proper course in this case is to let the People decide whether to retry the defendant on all charges. Cf. Crespin v. People, 721 P.2d 688 (Colo.1986) (prosecutor may make decision whether to retry defendant on charge or ask for conviction on lesser offense based on evidence from original trial).
We reverse that portion of the judgment of the court of appeals affirming the defendant’s guilty plea to attempted first degree murder and affirm the court of appeals' judgment with respect to the guilty plea to second degree burglary. We remand the ease to the court of appeals with directions to the district court to vacate the plea to attempted first degree murder. If the People wish to reinstate any of the original charges, they must do so within sixty days of the order vacating the plea. Then the district court is directed to vacate the guilty plea to second degree burglary if the defendant so moves within thirty days after the filing of the charges.
. The People apparently were prepared to file three more habitual criminal counts if the defendant did not plead guilty.
. The pending cases included separate charges of aggravated robbery, two second degree burglaries, theft, and carrying a concealed weapon.
. The district court judge who took the defendant’s plea is not the same judge who heard the Crim.P. 35(c) motion.
. The defendant was facing the possibility of a life sentence, for which he would have had to serve a minimum of twenty years; his sentence to a term of twenty-five to fifty years had a twelve year minimum.
. The defendant asserts that it is logically impossible to attempt felony murder because such a crime would require intent to commit the felony murder, not the burglary, and, by its nature, felony murder, unlike murder with deliberation, is an unintentional crime. See People v. Hernandez, 44 Colo.App. 161, 614 P.2d 900 (1980); People v. Viser, 62 Ill.2d 568, 343 N.E.2d 903 (1975); State v. Darby, 200 N.J.Super. 327, 491 A.2d 733 (1984); State v. Johnson, 103 N.M. 364, 707 P.2d 1174 (App.1985); Bailey v. State, 100 Nev. 562, 688 P.2d 320 (1984); State v. Howell, 649 P.2d 91 (Utah 1982). The People answer that several other jurisdictions have recognized attempted felony murder as a crime. See Wilson v. State, 272 Ark. 361, 614 S.W.2d 663 (1981); Amlotte v. State, 456 So.2d 448 (Fla.1984); Johnson v. State, 486 So.2d 657 (Fla.Dist.Ct.App.1986); Hardy v. State, 301 Md. 124, 482 A.2d 474 (1984). Because the advisement of attempted first degree murder does not meet the requirements of Crim.P. 11, we need not determine if there is such a crime as attempted felony murder.
. Section 18-4-401, 8 C.R.S. (1978), defines theft as follows:
(1) A person commits theft when he knowingly obtains or exercises control over anything of value of another without authorization, or by threat or deception, and:
(a) Intends to deprive the other person permanently of the use or benefit of the thing of value....
. Because the Court in Stone v. Powell, 428 U.S. 465, 96 S.Ct. 3037, 49 L.Ed.2d 1067 (1976), held that a defendant may not challenge evidence obtained in an unconstitutional search and seizure in a habeas corpus proceeding where the prisoner has had full and fair opportunity to litigate the fourth amendment claim in state court, cases raising fourth amendment challenges on collateral attack are now rare, occurring only in situations in which a state has failed to provide a prisoner with an opportunity for full and fair litigation of his claim, analo*1336gous federal cases under 28 U.S.C. § 2255 (1982), and collateral challenges by state prisoners under postconviction release statutes that recognize fourth amendment claims. Johnson, 457 U.S. at 562 n. 20, 102 S.Ct. at 2593 n. 20.
. Prospective application of a "new” constitutional rule allows those involved in the challenge that results in the new rule to benefit from the new rule. See Peltier, 422 U.S. at 542 n. 12, 95 S.Ct. at 2320 n. 12; Stovall, 388 U.S. at 300-01, 87 S.Ct. at 1971-72.
. A guilty plea does not preclude all challenges to the plea even when competent counsel is provided. See Menna v. New York, 423 U.S. 61, 96 S.Ct. 241, 46 L.Ed.2d 195 (1975) (per curiam) (double jeopardy claim is not waived by a plea); Blackledge v. Perry, 417 U.S. 21, 94 S.Ct. 2098, 40 L.Ed.2d 628 (1974) (guilty plea does not preclude challenge based on due process claim that state is retaliating for exercise of right to trial de novo by substituting more serious charge); Note, supra, 74 Colum.L.Rev. at 1460-62.