In this appeal, defendant-appellant Daryl E. Singleterry contests his jury conviction and resulting sentence for violation of federal drug trafficking laws. Singleterry raises two issues for our consideration. First, he pro *735 tests the district court’s refusal to instruct the jury to determine whether the prosecution produced sufficient evidence to establish the trustworthiness of his voluntary, extrajudicial confession. Second, Singleterry, who is black, maintains that his sentence violates the equal protection component of the Fifth Amendment because the difference in punishment for cocaine base (“crack”) offenses and cocaine (“cocaine powder”) offenses is either irrational or racially discriminatory. Finding neither argument persuasive, we affirm.
I.
BACKGROUND
On January 14, 1993, Maine law enforcement agents, responding to reports of drug dealing at the Days Inn in Eittery, Maine, commenced surveillance of the motel. That evening, they observed Jamee Landry, an associate of Singleterry, exit Room 225 with George Wilson, another Singleterry associate and suspected drug dealer. The two entered Landry’s car and drove to Portsmouth, New Hampshire, where the agents lost their trail. Early the next morning, after they saw Landry enter Room 225, the agents executed warrants to search both Room 225 and Landry’s car.
The search revealed a number of items probative of ongoing, armed drug trafficking. The agents first entered and searched Room 225, where they found Singleterry and Landry. They seized $2061 and a wallet containing Singleterry’s driver’s license from the pocket of a jacket on a night table in the room. Elsewhere in the room, the agents discovered two savings account passbooks, both in Singleterry’s name, with a combined balance of $5100. In Landry’s car, the agents found a plastic bag containing 6.46 grams of crack cocaine in the glove compartment, a leather gun holster on the front passenger seat, as well as a fully loaded semi-automatic handgun under the same seat.
After this search concluded, the agents arrested Singleterry, and properly informed him of his “Miranda rights.” Singleterry then provided the agents with a voluntary confession telling them that he personally paid $250 to his source in Lawrence, Massachusetts, for the cocaine base found in the vehicle. He also admitted that he had stolen the handgun seized by the agents, explaining that he needed the handgun to protect himself from individuals who were jealous of his cocaine business. In addition, Singleterry told the agents that he did not have a job, that he had been dealing cocaine base for a considerable period of time, and that the cash seized from his jacket pocket as well as the money in his savings accounts were proceeds from his sale of cocaine base in the Portsmouth, New Hampshire, area. Finally, Sin-gleterry stated that, as in this instance, he purchased most of the cocaine base he sold from a source in Lawrence or Lowell, Massachusetts. According to Singleterry, he would ordinarily pay $250 for a quarter ounce of cocaine base and then sell it for $1250.
Singleterry was charged in a three count indictment with possession with intent to distribute cocaine, 21 U.S.C. §§ 841(a)(1) and 841(b)(l)(B)(iii) (1988 & Supp. IV 1992) (Count I), the use and carrying of a firearm in connection with a drug trafficking offense, 18 U.S.C. § 924(c) (1988 & Supp. IV 1992) (Count II), and deriving certain personal property from proceeds obtained as the result of drug trafficking activity, 21 U.S.C. § 853 (1988) (Count III). The parties agreed to have the district court decide Count III on the basis of the trial evidence.
At trial, the government introduced evidence probative of the facts described above, relying heavily on the agents’ live testimony concerning Singleterry’s confession. At the close of the government’s case in chief, the defense moved for judgment of acquittal.
See
Fed.R.Crim.P. 29(a). Defendant’s primary contention was that the government’s evidence could not suffice to support a conviction because the government did not adequately corroborate Singleterry’s confession.
See Opper v. United States,
Singleterry timely requested a jury instruction that “as a matter of law a confession alone is not sufficient evidence upon which to convict the defendant, that the confession must be accompanied by additional corroborative [evidence] or sufficient indicia of reliability.” The district court refused to do so, explaining that the corroboration inquiry is for the court and not the jury. According to the district court, the role of the jury is simply to consider whether the evidence establishes each element of the offense beyond a reasonable doubt, although the jury is free to question the probative value of a confession in light of the strength or weakness of the corroborative evidence.
After deliberating for less than an hour, the jury convicted Singleterry on Counts I and II. The district court later issued an order of forfeiture in resolution of Count III.
At sentencing, the district court found that the offense level, including relevant conduct, involved a total of 73.66 grams of cocaine base, resulting in a base offense level of 32. United States Sentencing Commission, Guidelines Manual, § 2D1.1 (Nov.1993); see also 21 U.S.C. § 841(b)(1)(B) (prescribing minimum and maximum sentences). Because Singleterry had knowingly given false testimony at a pre-trial suppression hearing, the court added a two-level enhancement for obstruction of justice. U.S.S.G. § 3C1.1. With a total adjusted base offense level of 34 and a criminal history category of III, the guideline range on Count I was 188 to 235 months. 1 U.S.S.G. Ch. 5, Pt. A. The district court selected the minimum sentence of 188 months, imposing as well the consecutive 60 month sentence mandated by 18 U.S.C. § 924(c) for the firearm offense. In another ruling from the bench, the district court rejected Singleterry’s argument that stiffer penalties for cocaine base offenses, as opposed to cocaine powder offenses, violate Sin-gleterry’s right to equal protection of the law.
II.
DISCUSSION
A. Trustworthiness of Confessions and the Role of the Jury
Singleterry contends that the district court committed legal error when it refused to instruct the jury on the need for corroboration of his confession. Specifically, Singleter-ry urges us to adopt one of two propositions. First, he suggests that, when the government’s case rests primarily on a defendant’s confession, the district court must instruct the jury to find the confession to be trustworthy before considering it as evidence of guilt. Second, Singleterry asserts that, even in the absence of a general rule mandating such an instruction, the district court is obliged to instruct the jury on the corroboration requirement where the evidence of trustworthiness is so weak that a jury might differ from the court in its resolution of the question.
Whether the court must assign such a role to the jury is a pure question of law subject to plenary review.
See, e.g., United States v. Gallo,
To begin with, we note that a defendant’s own statements are never considered to be hearsay when offered by the government; they are treated as admissions, competent as evidence of guilt without any special guarantee of their trustworthiness.
See
Fed.R.Evid. 801(d)(2) & advisory com
*737
mittee’s note;
see also United States v. Barletta,
The doctrinal nature and procedural concomitants of the trustworthiness requirement announced in
Opper
are not entirely clear. Traditionally, the district court makes a preliminary determination as to whether testimony about the confession is sufficiently trustworthy for the jury to consider the confession as evidence of guilt.
See McCormick
§ 145, at 562; Corey J. Ayling, Comment,
Corroborating Confessions: An Empirical Analysis of Legal Safeguards Against False Confessions,
1984 Wis.L.Rev. 1121, 1140 (hereinafter “Ayling”). In this respect, the
Opper
rule essentially functions as a federal common law rule regulating the admission of statements which “are much like hearsay, [having had] neither the compulsion of the oath nor the test of cross-examination.”
Opper,
*738
At the same time, courts often characterize corroboration requirements as governing the
sufficiency
of the evidence.
See, e.g., Warszower,
It is within the uncertain framework of sufficiency that Singleterry positions his appeal. Singleterry does not claim that the district court erred in admitting evidence of his confession. Nor does he assert that the district court improperly found that the confession was adequately corroborated in denying the motion for judgment of acquittal. 5 Rather, Singleterry insists that, even after a court has properly admitted evidence of a confession and correctly tested the sufficiency of the evidence to support a conviction, the court has a responsibility, either generally or in certain cases, to instruct the jury to determine that the confession is trustworthy before considering it as evidence of guilt. This has never been the law in the federal courts, and we decline to adopt such a rule today.
Although we cannot accept Singleter-ry’s theory as such, we do not mean to suggest that the district court has no continuing duty to police the jury’s consideration of a confession’s probative value. First, if the district court loses confidence in its earlier determination of the corroboration issue and the evidence is otherwise inadequate to support a conviction, the proper course would be to enter a judgment of acquittal. Alternatively, if the government’s remaining evidence could support a finding of guilt but the jury’s incurable exposure to the confession raises serious questions about the prospect of a fair trial, the proper course would be to declare a mistrial.
See Stewart v. United States,
Second, a confession otherwise admissible under Opper may nevertheless be inadmissible “if its probative value is substantial *739 ly outweighed by the danger of unfair prejudice.” Fed.R.Evid. 40S. 6
Third, particularly where a full confession dominates the government’s proof, it is fair to assume that a jury will interpret its duty to find guilt beyond a reasonable doubt to mean that it cannot simply accept a confession at face value.
See D'Aquino v. United States,
Fourth, we note that a judge has wide latitude to select appropriate, legally correct instructions to ensure that the jury weighs the evidence without thoughtlessly crediting an out-of-court confession.
Cf Miller,
In this case, there is no indication that the district court overlooked its obligation to avoid or limit undue prejudice stemming from evidence of Singleterry’s confession. The district court had no occasion to exclude the confession under Rule 403, correctly found that the confession was trustworthy, and properly instructed the jury on the government’s burden of proof. Finally, in a manifestly appropriate exercise of discretion, the court directed the jury to “consider any ... facts or circumstances disclosed by the evidence ... tending to corroborate or to contradict the version of events which the witnesses have told you.”
In sum, there was no error in the lower court’s refusal to instruct the jury to apply the Opper trustworthiness requirement before considering Singleterry’s confession to be probative of his guilt.
B. Constitutionality of Sentencing Distinction Between Cocaine Base and Cocaine Powder
Singleterry maintains that his sentence on Count I is the product of an unconstitutional distinction between offenses involving cocaine base and those involving cocaine powder. See 18 U.S.C. § 841(b); U.S.S.G. § 2Dl.l(c) (equating 1 gram of cocaine base with 100 grams of cocaine). Singleterry did not contend below that the laws at issue are facially unconstitutional. Instead, he offered evidence in an attempt to demonstrate that the sentencing distinction between cocaine base and cocaine is either irrational, racially motivated, or both. On appeal, Singleterry essentially argues that the district court erroneously applied the relevant constitutional principles to the facts found at the sentencing hearing. We first recite the procedural rules that govern this portion of our analysis, then turn to a brief discussion of the merits.
While pure questions of law are subject to
de novo
review, we generally examine a district court’s fact-based determinations for clear error.
Williams v. Poulos,
11
*740
F.3d 271, 278 (1st Cir.1993);
In re Howard,
The clear error standard does not apply, however, when the fact-finding at issue concerns “legislative,” as opposed to “historical” facts.
See generally Dunagin v. City of Oxford,
1. Irrational Classification
It is well settled that an irrational classification imposed by federal law is violative of the equal protection component of the Fifth Amendment’s Due Process Clause.
See Miranda v. Secretary of Treasury,
Even if there is no telling difference in the health effects associated with the use of different types of cocaine, it would be rational to treat cocaine base offenses more harshly for other reasons. For example, Congress could rationally seek to strengthen the deterrent effect of the narcotics laws by increasing the “cost” to a criminal of using or selling a cocaine substance that, like cocaine base, is sold at a cheaper unit price than other cocaine substances. Indeed, of the four citations to the Congressional Record that Singleterry offers in his opening brief as probative of congressional intent, each suggests that Congress has been concerned that the low price of cocaine base (in the absolute sense as well as relative to cocaine) would lead to an explosion in drug use.
In any event, the district court correctly concluded that “Congress had before it sufficient ... information to make distinctions that would justify ... more severe sentences for trafficking in or using cocaine base or crack than cocaine itself.”
Accord United States v. Frazier,
%. Racially Discriminatory Classification
Singleterry next argues that the harsher penalties for cocaine base offenses are unconstitutional because they have such a disproportionate effect on blacks as to give rise to an inference that Congress and the
*741
Sentencing Commission established those penalties for the purpose of racial discrimination.
See Yick Wo v. Hopkins,
We agree that where evidence of disparate impact leads most naturally to an inference of discriminatory purpose, the governmental classification may be subject to strict scrutiny under equal protection principles.
See McCleskey v. Kemp,
Finally, we note that while “[t]he equal protection obligation imposed by the Due Process Clause of the Fifth Amendment is not an obligation to provide the best governance possible,”
Schweiker v. Wilson,
III.
CONCLUSION
For the foregoing reasons, we affirm Sin-gleterry’s conviction as well as his sentence.
So ordered.
Notes
. If Singleterry had been convicted of possession with intent to distribute cocaine powder, and if his relevant conduct raised the total of cocaine powder involved to 73.66 grams, his base offense level would have been 16, adjusted to 18 after the two-level enhancement. U.S.S.G. § 2D1.1 and § 3C1.1; see also 21 U.S.C. § 841(b)(1)(C) (prescribing maximum sentences). With a criminal history category of III, the guideline range on this count would have been 33 to 44 months.
. Many states adhere to a more traditional formulation of the corroboration rule, requiring independent proof of the corpus delicti ("body of the crime”), i.e., evidence independent of the confession showing that "(a) the injury or harm constituting the crime occurred; [and] (b) this injury or harm was done in a criminal manner.” 1 McCormick on Evidence § 145, at 557 (John William Strong ed., 4th ed. 1992) (hereinafter "McCormick”).
. Singleterry misinterprets this comment as suggesting that a full confession (one involving admissions to all elements of the crime) automatically bolsters itself, eliminating the need for proof of trustworthiness. According to Singlet-erry, "under Opper and Smith, the prosecution may rely entirely on a confession which is not even proven to be trustworthy and put forth no evidence establishing the corpus delicti." This is simply not so. The Court has never suggested that in certain cases the government would be relieved of the burden of proving the trustworthiness of a confession. Smith merely stands for the proposition that in the absence of independent evidence of the corpus delicti the government may establish the trustworthiness of the confession with other evidence typically used to bolster the credibility and reliability of an out-of-court statement.
. Note that Federal Rule of Evidence 804(b)(3) provides an important parallel. Under Rule 804(b)(3), a confession by someone other than the accused is treated as hearsay admissible as evidence of guilt if certain conditions are satisfied. Rule 804(b)(3) rests on the assumption that, in general, "persons will not make damaging statements against themselves unless they are true.” 4 Jack B. Weinstein & Margaret A. Berger,
Weinstein's Evidence
¶ 804(b)(3)[01], at 804-138 (1993). But such a confession cannot be used to prove the defendant’s guilt unless its use is necessitated by the unavailability of the declar-ant for courtroom testimony. Fed.R.Evid. 804(b). Additionally, we are waty of individuals who, as a result of mental illness, a fit of passion, a misplaced sense of sacrifice, or sheer mendacity, falsely incriminate themselves in order to spare another. Thus, "[a] statement tending to expose the declarant to criminal liability and offered to exculpate the accused is not admissible unless corroborating circumstances clearly indicate the trustworthiness of the statement." Fed. R.Evid. 804(b)(3). It is also significant that the trustworthiness criterion of Rule 804(b)(3) is "cast in terms of a requirement preliminary to admissibility,” Fed.R.Evid. 804(b)(3) advisory committee's note. As such, the district court makes the first and only official determination of trustworthiness, although it may be proper to instruct the jury that statements admissible under Rule 804(b)(3) "must be carefully scrutinized, weighed with great care, and received with caution.”
United States v. Miller,
. Two paragraphs in Singleterry's opening brief suggest that his appeal comprehends a challenge to the district court’s denial of the motion for acquittal. Nonetheless, Singleterry's reply brief states that "Appellant is not arguing that the evidence was insufficient for the court to determine that the corpus delicti existed. Appellant is not arguing that ... no rational trier of fact could find the corpus delicti sufficient." In any event, it is apparent that the district court did not err in finding that the government's evidence adequately established the trustworthiness of Singleterry’s confession. Proof of the presence in Landry’s car of 6.46 grams of cocaine base—a controlled substance in an amount substantial enough to suggest an intent to distribute—independently establishes the
corpus delicti
with respect to Count I. No more is required to demonstrate the trustworthiness of Singleteriy’s confession to the tangible crime of possession of cocaine base with intent to distribute.
See Wong Sun v. United States,
. Singleterry does not argue on appeal that the district court should have excluded evidence of the confession, or any portion thereof, on Rule 403 grounds.
