[1481] JOHN R. GIBSON, Circuit Judge.
The issue presented is whether under the Bail Reform Act of 1984, 18 U.S.C. § 3142, a district court,1 on review of a defendant’s appeal for a reduction of a magistrate’s bond order, may on its own motion call for a detention hearing and order a defendant detained pending trial. A panel of this court held that the district court is without the authority to do so. We granted rehearing en banc and we now hold that the district court has such power.* We thus affirm the order of the district court.
On May 21, 1985, Fleet Wallace Maull and six others were indicted on charges relating to various violations of federal narcotics and income tax laws. On May 23, 1985, a federal magistrate set Maull’s bond at one million dollars. On the same day, Maull moved to amend the conditions of the bond. An evidentiary hearing on the motion was held the following day. On May 28, the magistrate ruled that the evidence at the hearing revealed “that at this time no reduction in bond would reasonably assure the appearance of the defendant” and under 18 U.S.C. § 3142 ordered that the bond remain at one million dollars. Maull then sought review of his motion in the district court. Following a hearing there on May 30 (in which the evidence before the magistrate was stipulated to and which Maull’s counsel agreed was a de novo proceeding), the district court found that there was a serious risk Maull would flee and that a detention hearing was necessary to determine whether any condition or combination of conditions in section 3142(c) would reasonably assure his appearance. It conducted the hearing later that day over the vigorous objections of Maull’s counsel. The district court invited defendant to make what additional record he chose, but the parties simply stipulated to additional facts.
On May 31 the district court entered an order detaining Maull, finding that, in fact, no conditions set out in section 3142(c) could reasonably assure his appearance at trial. It stated that while section 3142(f) provides that a detention hearing shall be held immediately upon the defendant’s first appearance before a judicial officer, Maull’s appearance before the magistrate did not deprive the district court of the power under section 3145 to conduct a de novo review with the same options before it as had the magistrate.
Maull then appealed to this court. He argued first that the district court’s action was untimely under the provisions of section 3142(f). He also contended that the court exceeded the scope of its authority because the Bail Reform Act of 1984 does not confer jurisdiction on the district court to go beyond review of the conditions of a bail bond to consider whether pretrial detention is appropriate. The panel accepted these arguments in its reversal and remand of the district court’s order.
I.
We cannot endorse the panel’s interpretation of the Act. First, the district court did not exceed its authority. Maull correctly stated to the district court that its review should proceed de novo. As the Third Circuit has recently noted in United States v. Delker, 757 F.2d 1390 (3d Cir.1985), practice under the former statute, the provisions of the Federal Rules of Appellate Procedure, and the legislative history of the Act support this interpretation. See, e.g., United States v. Thibodeaux, 663 F.2d 520, 522 (5th Cir.1981) (prior review statute conferred “a responsibility on the district court to reconsider the conditions of release fixed by another judicial officer * * as unfettered as it would be if the district court were considering whether to amend its own action”); see also United States v. James, 674 F.2d 886, 890 (11th Cir.1982); United States v. Zuccaro, 645 F.2d 104, 106 (2d Cir.) cert. denied, 454 U.S. 823, 102 [1482] S.Ct. 110, 70 L.Ed.2d 96 (1981). As Delker points out, nothing in the new act suggests that Congress intended to change this practice:
[T]he legislative history states that § 3145 made only two substantial changes in the law: (1) permitting review of all releases irrespective of whether the defendant could or could not comply with the conditions of release; and (2) permitting the government to seek review and appeal of release decisions to the same extent that such authority is given defendants with respect to detention orders. This suggests that Congress intended the prior practice of de novo review to continue.
757 F.2d at 1394-95 (emphasis added).
Further, Rule 9 of the Federal Rules of Appellate Procedure provides that in an order refusing or imposing conditions of release, the district court must “state in writing the reasons for the action taken.” No similar requirement is placed on the magistrate with respect to a release order, 18 U.S.C. § 3142(h), although a detention order must contain written findings of fact and a written statement of the reasons for the detention. 18 U.S.C. § 3142(i)(l). Thus, particularly with respect to release orders, the requirement of Rule 9 could not effectively be met without de novo determinations.
To engage in a meaningful de novo review, the district court must have available the options open to the magistrate. The act requires a progression from one choice to the next in a judicial officer's determination of whether pretrial detention is called for. See United States v. Orta, 760 F.2d 887, 890 (8th Cir.1985) (en banc). Only after determining that release upon personal recognizance or an unsecured appearance bond will not reasonably assure appearance or will endanger the safety of others {see 18 U.S.C. § 3142(b)), may the judicial officer then proceed to consider the conditions set out in section 3142(c)(2)(A)-(N). In reviewing the order of the magistrate, the district court must engage in this same analysis. It was in making this analysis that the district court determined that none of the conditions of section 3142 would assure Maull’s appearance. It then had no alternative but to deny bail.
The legislative history of the Bail Reform Act particularly addresses the situation which developed in Maull’s request for review:
f a judicial officer determines that a $50,000 bond is the only means, short of detention, of assuring the appearance of a defendant who poses a serious risk of flight, and the defendant asserts that, despite the judicial officer’s finding to the contrary, he cannot meet the bond, the judicial officer may reconsider the amount of the bond. If he still concludes that the initial amount is reasonable and necessary then it would appear that there is no available condition of release that will assure the defendant’s appearance. This is the very finding which, under 3142(e), is the basis for an order of detention, and therefore the judge may proceed with a detention hearing pursuant to section 3142(f).
S.Rep. No. 225, 98th Cong., 1st Sess. 16, reprinted in 1984 U.S.Code Cong. & Ad. News 3182, 3199 (emphasis added). Maull argued before the magistrate that he could not post a one million dollar bond. When the district court concluded that there was a serious risk of flight, knowing, as it did, of Maull’s claim, it acted within the intent expressed by Congress in proceeding to a detention hearing.
Maull argues and the panel found that the action of the district court was untimely, since no detention hearing was held immediately “upon the person’s first appearance before the judicial officer.” 18 U.S.C. § 3142(f). This position ignores the fact that this was Maull’s first appearance before the district court, after it of its own motion called for a detention hearing.2 [1483] Further, we agree with the Delker court that this portion of the act does not “suggest * * * that a hearing may be had only upon the defendant’s appearance before the first judicial officer he or she faces. Rather, the import of the clause is to call for a prompt hearing on the issue of detention.” 757 F.2d at 1394. The cases relied upon by Maull and by the panel in support of its action are distinguishable. Both involve multiple appearances before the same judicial officer with motions for detention filed by the government after the first appearance. In United States v. O’Shaughnessy, 764 F.2d 1035 (5th Cir.1985), the court held that the government’s failure to move for pretrial detention on the defendant’s initial appearance, even though it did so move six days later at his arraignment, made the later detention hearing untimely. The court simply reasoned that its holding was required by the statutory language. Accord United States v. Payden, 759 F.2d 202, 204 (2d Cir.1985) (“Act requires that the detention hearing be held on defendant’s first appearance”). Further, the cases overlook, as did the panel in its order, the context of the statute. Section 3142(f) provides:
[t]he judicial officer shall hold a [detention] hearing * * * [u]pon motion of the attorney for the Government or upon this judicial officer’s own motion, that involves—
(A) - a serious risk that the person will flee;
(B) a serious risk that the person will obstruct or attempt to obstruct justice, or threaten, injure, or intimidate, or attempt to threaten, injure, or intimidate, a prospective witness or juror.
The hearing shall be held immediately upon the person’s first appearance before the judicial officer unless that person, or the attorney for the Government, seeks a continuance.
O’Shaughnessy and Pay den as well as the panel seized upon only the language in the final sentence quoted above. That sentence, however, must be read with the immediately preceding language which allows the judicial officer on his or her own motion to hold a detention hearing. A fair reading of the statute is not that a detention hearing must be held “immediately” when a defendant first appears in court, else to be forever barred, but rather that once a motion, for pretrial detention is made,3 a hearing must occur promptly thereafter. This reading, consistent with Delker, serves the spirit of the statute and avoids the technical trap a hasty reading produces. Here the magistrate did not hold a detention hearing because he accepted the government’s recommendation of the one million dollar bond and found that this condition would reasonably assure Maull’s appearance. The district court, however, found a serious risk of flight and applied this part of the statute to immediately call a detention hearing. This was done upon Maull’s first appearance before the district court. We conclude that this procedure is consistent with the statute.
As the O’Shaughnessy court recognized, its interpretation of the statute creates potential problems, such as the unavailability of pretrial detention when “information establishing a defendant to be a danger to others comes into the Government’s possession shortly after the initial appearance.”4 [1484] Uhited States v. O’Shaughnessy, 764 F.2d at 1038. Even more centrally, the decision relies on a restricted reading of one phrase of the act to defeat Congress’s intent to give judges “the tools to make honest and appropriate decisions” regarding pretrial detention. S.Rep. No. 225, 98th Cong., 1st Sess. 5, reprinted in 1984 U.S.Code Cong. & Ad.News 3182, 3188.
Our view of Payden and O’Shaughnessy conforms to that expressed recently by the United States Court of Appeals for the Fifth Circuit in United States v. Fortna, 769 F.2d 243 (5th Cir.1985). In Fortna, when the defendant first appeared before the magistrate following the filing of a complaint, the magistrate sua sponte called for a detention hearing to determine whether to grant bond or detain the defendant. The hearing was held and the magistrate, finding that the defendant posed a serious non-physical danger to the community because of his key role in a major cocaine importing organization, denied bond. The district court, upon appeal, not only affirmed the magistrate’s ruling on the proffered ground, but went further to find that defendant posed a serious risk of flight if released and that no combination of conditions would reasonably assure his appearance at trial. Judge Garwood’s opinion affirming the action of the district court is instructive:
When the district court, pursuant to 18 U.S.C. § 3145(b), acts on a motion to revoke or amend a magistrate’s pretrial detention order, the court acts de novo and makes an independent determination of the proper pretrial detention or conditions for release. See United States v. Freitas, 602 F.Supp. [1283] at 1293 [(1985)]. Cf. United States v. Thibo-deaux, 663 F.2d 520, 522 (5th Cir.1981) (same under prior law). Moreover, the rule of de novo determination by the district court applies not only when the accused challenges the magistrate’s order, but also when the government does, as it is authorized to do by section 3145(a)(1). United States v. Delker, 757 F.2d 1390, 1394 (3d Cir.1985) (relying on our Thibodeaux opinion). In such a situation, the district court, making an independent determination, can order pretrial detention even though the magistrate has refused to do so. Delker, supra. That being the case, we see no reason why the district court, having had the magistrate’s ruling properly brought before it, cannot support what the magistrate has actually ordered with additional findings based on its independent consideration of the record before the magistrate and the additional evidence adduced before it “as unfettered as it would be if the district court were considering whether to amend its own action.” Thi-bodeaux, 663 F.2d at 527. (Footnote omitted).
United States v. Fortna, 769 F.2d at 250.
This approach supports the decision we reach today. Fortna ratifies the propriety of the exercise of power by the district court to consider upon de novo review grounds other than those considered by the magistrate. Judge Filippine’s action, the [1485] issuance of a detention order when the magistrate had not done so, constitutes a similarly proper exercise of power on de novo review.5 Thus, when Maull raised the issues on appeal, the district court, as the judicial officer ultimately responsible for trial of the case, applied the de novo standard. Upon finding that there was likelihood of flight, it was required to analyze the conditions of release to determine whether any would give reasonable assurance of appearance. When it found none existed, it had the duty under the Bail Reform Act to deny release. To hold that the judge responding to this duty only may lighten the conditions already imposed, but not bolster them, would emasculate the essential scope of the statute.
Maull argues that to deny release upon appeal from the bond set by the magistrate violates the fifth amendment right of due process. His argument, which echoes the reasoning of North Carolina v. Pearce, 395 U.S. 711, 89 S.Ct. 2072, 23 L.Ed.2d 656 (1969), essentially is that the imposition of bond or detention during the pretrial phase of the proceeding is punishment and that the specter of increased punishment following appeal creates a chilling effect on the criminal defendant’s exercise of appeal rights. . Pearce, however, concerned the imposition of a more severe punishment following conviction on a retrial after a successful appeal. On the other hand, while pretrial detention involves incarceration and necessarily a great diminution of personal liberty, it is not punishment if it serves a legitimate regulatory purpose which outweighs its punitive aspects and is not excessive in relationship to that purpose. United States v. Edwards, 430 A.2d 1321, 1332 (D.C.Ct.App.1981) (en bane), cert. denied, 455 U.S. 1022, 102 S.Ct. 1721, 72 L.Ed.2d 141 (1982).6 See also Bell v. Wolfish, 441 U.S. 520, 561, 99 S.Ct. 1861, 1885, 60 L.Ed.2d 447 (1979). Here the district court’s purpose for imposing pretrial detention was clearly regulatory: to protect the integrity of the judicial process by insuring that the defendant would be present to stand trial for the crimes accused. Nor given Maull’s earlier actions and the seriousness of the charges may it reasonably be deemed excessive. Thus, such detention is not punishment. Moreover, in Pearce, the court sought to attack a perceived vindictiveness which motivated the increased sentences. North Carolina v. Pearce, 395 U.S. at 725, 89 S.Ct. at 2080. Here it was not vindictiveness but the prevention of pretrial flight, which moved Congress to authorize district courts, upon evaluation of the record in light of the sequential standards set out in section 3142, to impose detention. District court review of the earlier judicial officer’s order on the question of detention constitutes an exercise of most significant judicial authority. . It is not prosecutorial in nature. When the judge finds that no condition can reasonably prevent defendant’s flight, he or she is empowered to detain. Assuring appearance at trial long has been a proper concern of district courts. United States v. Jessup, 757 F.2d 378, 387 (1st Cir.1985); United States v. Golding, 742 F.2d 840 (5th Cir.1984). These distinctions render Maull’s reliance on Pearce unavailing.
The argument that allowing the same judicial officer to move for detention and then to conduct the detention hearing violates due process principles, as it would [1486] in the context of contempt proceedings, similarly is unavailing. First, this is precisely what is contemplated by the statute. Second, the decision to detain is not a determination of guilt on the underlying charge. Rather, this procedure is designed to sustain the integrity of the judicial function by-insuring the appearance of the defendant at trial. As such it implicates only limited due process concerns which are not here transgressed.
Still another observation is in order. Sections 3145(a) and (b) underscore the importance of the judge having original jurisdiction over the offense. We do not believe that this substantial responsibility, placed in the hands of an Article III judge, can be diminished by the earlier action of a magistrate. In vesting decision-making authority in magistrates under the Federal Magistrates Act, 28 U.S.C. § 636, Congress was sensitive to Article III values. It emphasized that “the magistrate acts subsidiary to and only in aid of the district court,” and that “the entire process takes place under the district court’s total control and jurisdiction.” United States v. Raddatz, 447 U.S. 667, 681, 100 S.Ct. 2406, 2415, 65 L.Ed.2d 424 (1980). Congressional intent to limit the scope of magistrate authority is reinforced by the charge of 18 U.S.C. § 3142(f), which gives the judicial officer upon his own motion the authority to call a detention hearing where there is a serious risk that the defendant will flee. The power to decide must finally reside in the Article III court. We thus cannot conclude that the government’s failure to request detention before the magistrate, or for that matter at all, constrains the district court judge.
We conclude that the district court had the authority under § 3142 to call for and conduct the detention hearing, and finding that no condition of release would reasonably assure Maull’s appearance, to order detention. Any other result would do violence to the statutory context of pretrial detention procedure under the Bail Reform Act, the intent of Congress in passing the Act, the responsibility explicitly given district judges to move for a detention hearing, and the mandated relationship between magistrates and the district court under the Federal Magistrates Act and Article III.
II.
Having determined that the district court had the authority to order detention, we must now consider the propriety of that order. First, we turn to the standard that governs our review of this question. Our circuit has not addressed this issue. In the past our rulings may have followed differing approaches. Several circuits have held that district court decisions regarding pretrial detention are to be judged under the clearly erroneous standard. United States v. Chimurenga, 760 F.2d 400, 405 (2d Cir. 1985); United States v. Williams, 753 F.2d 329, 333 (4th Cir.1985).7 The Third Circuit, however, has determined that “courts of appeals must independently assess the merits of applications for release on bail pending appeal once denied by the trial court.” United States v. Provenzano, 605 F.2d 85, 92 (3d Cir.1979); see United States v. Delker, 757 F.2d at 1400 (Provenzano standard applicable under Bail Reform Act).
Chimurenga and Williams do not carefully analyze the issue. Provenzano, however, engages in a detailed examination of the reasons for its approach. The court there looked to the practice of individual justices of the Supreme Court sitting as circuit justices in considering bail applications. The in-chambers opinions arising from such applications have “uniformly established that although district court decisions respecting bail are entitled to ‘great [1487] deference/ a Circuit Justice has a non-dele-gable responsibility to make an independent determination of the merits of the application.” 605 F.2d at 92; see Truong Dinh Hung v. United States, 439 U.S. 1326, 1328, 99 S.Ct. 16, 17, 58 L.Ed.2d 33 (Brennan, Circuit Justice, 1978); Mecom v. United States, 434 U.S. 1340, 98 S.Ct. 19, 54 L.Ed.2d 49 (Powell, Circuit Justice, 1977); Harris v. United States, 404 U.S. 1232, 92 S.Ct. 10, 30 L.Ed.2d 25 (Douglas, Circuit Justice, 1971); Sellers v. United States, 89 S.Ct. 36, 21 L.Ed.2d 64 (Black, Circuit Justice, 1968). It follows that a panel of the court of appeals should assume the same obligation as that of a circuit justice. If not, as a practical matter alone, a greater number of petitions to the Supreme Court would result, in hopes of a broader review than that given by the panel of the circuit court.
The Provenzano court also relied on Rule 9 of the Federal Rules of Appellate Procedure, which states that motions for release shall be heard by an appellate court “upon such papers, affidavits, and portions of the record as the parties shall present.” Thus, because “this requirement permits consideration by the court of appeals of evidence that may not have been before the trial judge, it, too, indicates that the court of appeals should independently determine such applications.” 605 F.2d at 93. In Delker, the court noted that the legislative history makes clear that the procedures for appeal are still those “set forth in Rule 9 of the Federal Rules of Appellate Procedure.” 757 F.2d at 1399 (quoting S.Rep. No. 225, 98th Cong., 1st Sess. 29 n. 92, reprinted in 1984 U.S.Code Cong. & Ad.News 3182, 3212 n. 92). The Delker court then stated:
Rule 9’s requirements mandate-that appellate courts give the reasons articulated by trial judges respectful consideration, but if, after careful assessment of the trial judge’s reasoning, together with such papers, affidavits, and portions of the record as the parties present, the court of appeals independently reaches a conclusion different from that of the trial judge the court of appeals has the power to amend or reverse a detention or release decision.
757 F.2d at 1400.
While we find the Third Circuit’s analysis persuasive, we do not believe it is totally inconsistent with the approach of Chimurenga and Williams. Both Provenzano and Delker state that the trial judge’s reasons must be independently reviewed but do not address explicitly the deference to be accorded factual findings. In criminal cases tried to a court, factual findings made by the trial judge, where they concern matters other than the ultimate question of guilt, must stand unless clearly erroneous. Campbell v. United States, 373 U.S. 487, 493, 83 S.Ct. 1356, 1360, 10 L.Ed.2d 501 (1963); United States v. Londe, 587 F.2d 18, 20 (8th Cir.1978) cert. denied, 439 U.S. 1130, 99 S.Ct. 1050, 59 L.Ed.2d 92 (1979). The Supreme Court recently has underscored the importance of this standard of review in civil cases. See Anderson v. City of Bessemer City, — U.S. -, 105 S.Ct. 1504, 84 L.Ed.2d 518 (1985). We believe that in review under section 3145 the clearly erroneous standard should be applied to factual findings made by the district court. Many of the issues in such cases will involve issues of credibility best determined by the trier of fact. However, conclusions and reasoning relating to the ultimate questions flowing from such factual considerations — issues such as the reasonable likelihood of success on appeal and the determination of the conditions that will reasonably assure the appearance of the defendant — should be the subject of independent review. See United States v. Hazime, 762 F.2d 34, 37 (6th Cir.1985) (in appellate review of pretrial detention, factual findings not disturbed unless clearly erroneous, but de novo consideration given ultimate conclusions and mixed questions of law and fact).8 As further illustration of the distinction, we observe that the [1488] factors of section 3142(g)(3) and (4) relating to the individual characteristics of the defendant and the nature and seriousness of the danger to any person or the community that would be posed by the person’s release involve primarily factual issues. On the other hand, the factors of section 3142(g)(1) and (2) involving the nature and circumstances of the offense and the weight of the evidence against the person, as well as the analysis of the conditions of release of section 3142(c)(2)(A)-(N), particularly involve legal or judgmental assessments which are based on factual findings. We need not draw the issue more finely here as our study of a district court’s order in any particular case should adequately reveal what are findings of fact that must be reviewed under the clearly erroneous rule and what are conclusions of law or articulations of reasoning that must be independently reviewed.
III.
The district court in its order of May 31 found by clear and convincing evidence that there was no condition or set of conditions that would reasonably assure Maull’s appearance.9 It set out factors to be considered as contained in 18 U.S.C. § 3142(g). The district court made the following findings in its order.
The defendant, who currently resides in Colorado, is charged with several narcotic violations, including the charge of continuing criminal enterprise. The maximum sentence possible under these charges is imprisonment for life plus fifty years together with substantial fines and forfeitures. In addition, based on the government’s indication that it will call as witnesses alleged co-conspirators of the defendant and will present tape recordings implicating the defendant, there appears to be substantial evidence against the defendant. These two factors create a strong temptation for the defendant to flee in order to escape prosecution; a temptation to which defendant has already succumbed when in August of 1983 he used false identification to escape prosecution in Curacao in the Netherlands Antilles.
The district court then set out in detail the incident in Curacao in which Maull and three others arrived with four backpacks equipped with secret compartments containing some twenty pounds of cocaine. The backpacks were seized by customs agents at the airport and Maull and one other escaped while the other two were arrested. The escape from Curacao was described in the agent’s testimony again set out in full in the district court’s order:
My investigation revealed that upon seeing Mr. Kendrick and Rankin detained by customs authorities in, at the airport in Curacao, Mr. Busch and Mr. Maull passed through customs there without declaring any baggage, left the island, stayed on the island of Curacao in hiding, altered their appearance and secured birth certificates and fictitious names, or names other than their own, were given those passports or those birth certificates by a third party and subsequently, after approximately three to five days escaped from the island of Curacao and escaped prosecution there also.
The agent further testified that the passports and birth certificates were transported to Curacao by Maull’s female companion. The district court also found that Maull had numerous connections with people living abroad who might be willing to assist him and that he was fluent in Spanish and capable of traveling with ease throughout many countries in South America. The court also found significant that Maull’s passport was found hidden in the house formerly owned by him, secreted in a light fixture. It found “this also indicates preparation to flee prosecution.” Our [1489] study of the record convinces us that the findings of fact were not clearly erroneous. Making an independent determination of the ultimate conclusion as to whether any conditions would reasonably assure Maull’s appearance at trial, we are satisfied that detention was required.
We affirm the order of the district court detaining Maull pending trial.