opinion: Justice Powell
  delivered the opinion of the Court.
  In this case we must decide, first, whether the Speedy Trial Clause of the Sixth Amendment applies to time during which respondents were neither under indictment nor subjected to any official restraint, and, second, whether certain delays occasioned by interlocutory appeals were properly weighed in assessing respondents’ right to a speedy trial. A divided panel of the Court of Appeals for the Ninth Circuit weighed most of the 90 months from the time of respondents’ arrests and initial indictment in November 1975 until the District Court’s dismissal of the indictment in May 1983 towards respondents’ claims under the Speedy Trial Clause. We conclude that the time that no indictment was outstanding against respondents should not weigh towards respondents’ speedy trial claims. We also find that in this case the delay attributable to interlocutory appeals by the Government and respondents does not establish a violation of the Speedy Trial Clause. Accordingly, we reverse the holding of the Court of Appeals that respondents were denied their right to a speedy trial.
  I — (
  In view of the nature of respondents’ claim, we state the factual and procedural history of this case in some detail. On November 14, 1975, pursuant to a tip from the Federal Bureau of Investigation, Oregon state troopers stopped two vehicles in search of several federal fugitives. After an exchange of gunfire and a motor chase, state troopers captured all but one of the respondents, Dennis Banks. Both vehicles were locked and impounded while federal and state authorities obtained search warrants.
  Searches of the vehicles over the next two days disclosed 350 pounds of dynamite, 6 partially assembled time bombs, 2,600 rounds of ammunition, 150 blasting caps, 9 empty hand grenades, and miscellaneous firearms. Oregon law enforcement officers, apparently unaware of the evidentiary consequences, adhered to their usual policy and destroyed the dynamite. A federal agent present at the destruction photographed the explosions. United States v. Loud Hawk, 628 F. 2d 1139, 1142 (CA9 1979). State officials also preserved wrappers from the dynamite casings.
  A federal grand jury indicted respondents on November 25, 1975, on charges of possessing firearms and explosives. Trial in the United States District Court for the District of Oregon was set for the week of February 9, 1976. On December 22, 1975, a grand jury returned a five-count superseding indictment. This indictment charged all respondents with three counts relating to possession and transportation in commerce of an unregistered destructive device (the dynamite counts) and two counts relating to unlawful possession of firearms (the firearms counts).
  Two days later, respondents filed a motion to suppress all evidence concerning the dynamite, arguing that federal and state officials had intentionally and negligently destroyed the dynamite before the defense had the opportunity to examine it. After initially denying respondents’ motion, and after two continuances at respondents’ behest, the District Court granted respondents’ motion to suppress on March 31, 1976. App. to Pet. for Cert. 157a. Three weeks later, the Government appealed the suppression order, and moved that trial on all counts be continued pending the outcome of the appeal. The District Court denied the Government’s request for a continuance, and when the case was called for trial, the Government answered “not ready.” Pursuant to Federal Rule of Criminal Procedure 48(b), the District Judge dismissed the indictment with prejudice. Six months had passed since the original indictment.
  The Government immediately appealed the dismissal, and the two appeals were consolidated. The Court of Appeals heard argument on October 15, 1976, and a divided panel affirmed in an unreported opinion on July 26, 1977. App. to Pet. for Cert. 88a-118a. On the Government’s motion, the court voted on October 17, 1977, to hear the case en banc. On March 6, 1978, the Court of Appeals en banc remanded for findings of fact on whether federal officials participated in the destruction of the dynamite and whether respondents were prejudiced by its destruction. The court retained jurisdiction over the appeal pending the District Court’s findings. The District Court issued its findings on August 23, 1978, and the case returned to the Court of Appeals.
  On August 7, 1979, the Court of Appeals reversed the suppression order and directed that the dynamite counts be reinstated. United States v. Loud Hawk, 628 F. 2d, at 1150. The court also held that although the Government could have gone to trial on the firearms counts pending the appeal, the District Court erred in dismissing those counts with prejudice. Id., at 1151. The Court of Appeals denied respondents’ petition for rehearing on October 1, 1979. Respondents petitioned for certiorari; we denied the petition on March 3, 1980. 445 U. S. 917. The mandate of the Court of Appeals issued on March 12, 1980, 46 months after the Government filed its notice of appeal from the dismissal of the indictment. Respondents were unconditionally released during that time.
  Following remand, the District Court ordered the Government to reindict on the firearms charges. Respondents filed a number of motions during June and July of 1980 in response to the superseding indictment, including a motion to dismiss for vindictive prosecution. On August 8, 1980, the District Court granted the vindictive prosecution motion as to KaMook Banks and denied it as to respondents Dennis Banks, Render, and Loud Hawk. Both sides appealed. Respondents remained free on their own recognizance during this appeal.
  The appeals were consolidated, and the Court of Appeals ordered expedited consideration. The court heard argument on January 7,1981, but did not issue its decision until July 29, 1982. The court sustained the Government’s position on all issues. United States v. Banks, 682 F. 2d 841. Respondents’ petitions for rehearing were denied on October 5, 1982. Respondents again petitioned for certiorari, and we denied the petition on January 10, 1983. 459 U. S. 1117. The Court of Appeals’ mandate issued on January 31, 1983, almost 29 months after the appeals were filed.
  The District Court scheduled trial to begin on April 11, 1983. The Government sought and received a continuance until May 3, 1983, because of alleged difficulties in locating witnesses more than seven years after the arrests. Subsequently, the court on its own motion continued the trial date until May 23, 1983, and then again rescheduled the trial for June 13. The record in this Court does not reveal the reasons for these latter two continuances. Defendants objected to each continuance.
  On May 20, 1983, the District Court again dismissed the indictment, this time on the ground that respondents’ Sixth Amendment right to a speedy trial had been violated. 564 F. Supp. 691. The Government appealed, and unsuccessfully urged the District Court to request that the Court of Appeals expedite the appeal. On its own motion the court treated the appeal as expedited, and heard argument on January 4, 1984. A divided panel affirmed on August 30, 1984. 741 F. 2d 1184. We granted certiorari, 471 U. S. 1014 (1985), and now reverse.
  II
  The Government argues that under United States v. MacDonald, 456 U. S. 1 (1982), the time during which defendants are neither under indictment nor subject to any restraint on their liberty should be excluded — weighed not at all — when considering a speedy trial claim. Respondents contend that even during the time the charges against them were dismissed, the Government was actively pursuing its case and they continued to be subjected to the possibility that bail might be imposed. This possibility, according to respondents, is sufficient to warrant counting the time towards a speedy trial claim.
  The Court has found that when no indictment is outstanding, only the “actual restraints imposed by arrest and holding to answer a criminal charge . . . engage the particular protections of the speedy trial provision of the Sixth Amendment.” United States v. Marion, 404 U. S. 307, 320 (1971) (emphasis added); see MacDonald, supra, at 9. As we stated in MacDonald: “The speedy trial guarantee is designed to minimize the possibility of lengthy incarceration prior to trial, to reduce the lesser, but nevertheless substantial, impairment of liberty imposed on an accused while released on bail, and to shorten the disruption of life caused by arrest and the presence of unresolved criminal charges.” 456 U. S., at 8.
  During much of the litigation, respondents were neither under indictment nor subject to bail. Further judicial proceedings would have been necessary to subject respondents to any actual restraints. Cf. Klopfer v. North Carolina, 386 U. S. 213 (1967). As we stated in MacDonald: “[W]ith no charges outstanding, personal liberty is certainly not impaired to the same degree as it is after arrest while charges are pending. After the charges against him have been dismissed, ‘a citizen suffers no restraints on his liberty and is [no longer] the subject of public accusation: his situation does not compare with that of a defendant who has been arrested and held to answer.’” 456 U. S., at 9.
  Respondents argue that the speedy trial guarantee should apply to this period because the Government’s desire to prosecute them was a matter of public record. Public suspicion, however, is not sufficient to justify the delay in favor of a defendant’s speedy trial claim. We find that after the District Court dismissed the indictment against respondents and after respondents were freed without restraint, they were “in the same position as any other subject of a criminal investigation.” MacDonald, supra, at 8-9. See Marion, supra, at 309. The Speedy Trial Clause does not purport to protect a defendant from all effects flowing from a delay before trial. The Clause does not, for example, limit the length of a pre-indictment criminal investigation even though “the [suspect’s] knowledge of an ongoing criminal investigation will cause stress, discomfort, and perhaps a certain disruption in normal life.” 456 U. S., at 9.
  Nor does the fact that respondents were ordered to appear at the evidentiary hearing held on remand in the District Court during the first appeal — an appearance they waived— constitute the sort of “actual restraint” required under our precedents as a basis for application of the Speedy Trial Clause. Finally, we are not persuaded that respondents’ need for counsel while their case was technically dismissed supports their speedy trial claim. Although the retention of counsel is frequently an inconvenience and an expense, the Speedy Trial Clause’s core concern is impairment of liberty; it does not shield a suspect or a defendant from every expense or inconvenience associated with criminal defense.
  We therefore find that under the rule of MacDonald, when defendants are not incarcerated or subjected to other substantial restrictions on their liberty, a court should not weigh that time towards a claim under the Speedy Trial Clause.
  I — I h-H h — i
  The remaining issue is how to weigh the delay occasioned by an interlocutory appeal when the defendant is subject to indictment or restraint. As we have recognized, the Sixth Amendment’s guarantee of a speedy trial “is an important safeguard to prevent undue and oppressive incarceration prior to trial, to minimize anxiety and concern accompanying public accusation and to limit the possibilities that long delay will impair the ability of an accused to defend himself.” United States v. Ewell, 383 U. S. 116, 120 (1966). These safeguards may be as important to the accused when the delay is occasioned by an unduly long appellate process as when the delay is caused by a lapse between the initial arrest and the drawing of a proper indictment, Ewell, supra, at 118-119, or by continuances in the date of trial, Barker v. Wingo, 407 U. S. 514, 517-518 (1972).
  At the same time, there are important public interests in the process of appellate review. The assurance that motions to suppress evidence or to dismiss an indictment are correctly decided through orderly appellate review safeguards both the rights of defendants and the “rights of public justice.” Beavers v. Haubert, 198 U. S. 77, 87 (1905). The legislative history of 18 U. S. C. § 3731 “makes it clear that Congress intended to remove all statutory barriers to Government appeals and to allow appeals whenever the Constitution would permit.” United States v. Wilson, 420 U. S. 332, 337 (1975).
  It is, of course, true that the interests served by appellate review may sometimes stand in opposition to the right to a speedy trial. But, as the Court observed in United States v. Ewell, supra, at 121:
  “It has long been the rule that when a defendant obtains a reversal of a prior, unsatisfied conviction, he may be retried in the normal course of events. . . . [This rule] has been thought wise because it protects the societal interest in trying people accused of crime, rather than granting them immunization because of legal error at a previous trial, and because it enhances the probability that appellate courts will be vigilant to strike down previous convictions that are tainted with reversible error. . . . These policies, so carefully preserved in this Court’s interpretation given the Double Jeopardy Clause, would be seriously undercut by [an] interpretation given the Speedy Trial Clause [that raised a Sixth Amendment obstacle to retrial following successful attack on conviction].”
  In Barker, we adopted a four-part balancing test to determine whether a series of continuances infringed upon the defendant’s right to a speedy trial. 407 U. S., at 530. That test assessed the “[l]ength of delay, the reason for the delay, the defendant’s assertion of his right, and prejudice to the defendant.” Ibid (footnote omitted). The Barker test furnishes the flexibility to take account of the competing concerns of orderly appellate review on the one hand, and a speedy trial on the other. We therefore adopt this functional test to determine the extent to which appellate time consumed in the review of pretrial motions should weigh towards a defendant’s speedy trial claim. Under this test, we conclude that in this case the delays do not justify the “unsatisfactorily severe remedy of dismissal.” Id., at 522.
  A
  Barker’s first, third, and fourth factors present no great difficulty in application. The first factor, the length of delay, defines a threshold in the inquiry: there must be a delay long enough to be “presumptively prejudicial.” Id., at 530. Here, a 90-month delay in the trial of these serious charges is presumptively prejudicial and serves to trigger application of Barkers other factors. Ibid.
  The third factor — the extent to which respondents have asserted their speedy trial rights — does not support their position. Although the Court of Appeals found that respondents have repeatedly moved for dismissal on speedy trial grounds, 741 F. 2d, at 1192, that finding alone does not establish that respondents have appropriately asserted their rights. We held in Barker that such assertions from defendants are “entitled to strong evidentiary weight” in determining whether their rights to a speedy trial have been denied. 407 U. S., at 531-532. These assertions, however, must be viewed in the light of respondents’ other conduct.
  Here, respondents’ speedy trial claims are reminiscent of Penelope’s tapestry. At the same time respondents were making a record of claims in the District Court for speedy trial, they consumed six months by filing indisputably frivolous petitions for rehearing and for certiorari after this Court’s decision in United States v. Hollywood Motor Car Co., 458 U. S. 263 (1982) (federal courts without jurisdiction to hear defendant’s interlocutory appeal from denial of motion to dismiss indictment). They also filled the District Court’s docket with repetitive and unsuccessful motions. See, e. g., n. 10, supra.
  The Court of Appeals gave “little weight” to the fourth factor, prejudice to respondents. At most, the court recognized the possibility of “impairment of a fair trial that may well result from the absence or loss of memory of witnesses in this case.” 741 F. 2d, at 1193. See Barker, 407 U. S., at 532. That possibility of prejudice is not sufficient to support respondents’ position that their speedy trial rights were violated. In this case, moreover, delay is a two-edged sword. It is the Government that bears the burden of proving its case beyond a reasonable doubt. The passage of time may make it difficult or impossible for the Government to carry this burden.
  B
  The flag all litigants seek to capture is the second factor, the reason for delay. In Barker, we held that “different weights should be assigned to different reasons.” Id., at 531. While a “deliberate attempt to delay the trial in order to hamper the defense,” would be weighed heavily against the Government, a delay from “overcrowded courts” — as was the situation here — would be weighed “less heavily.” Ibid. Given the important public interests in appellate review, supra, at 313, it hardly need be said that an interlocutory appeal by the Government ordinarily is a valid reason that justifies delay. In assessing the purpose and reasonableness of such an appeal, courts may consider several factors. These include the strength of the Government’s position on the appealed issue, the importance of the issue in the posture of the case, and — in some cases — the seriousness of the crime. United States v. Herman, 576 F. 2d 1139, 1146 (CA5 1978) (Wisdom, J.). For example, a delay resulting from an appeal would weigh heavily against the Government if the issue were clearly tangential or frivolous. Ibid. Moreover, the charged offense usually must be sufficiently serious to justify restraints that may be imposed on the defendant pending the outcome of the appeal. Ibid.
  Under Barker, delays in bringing the case to trial caused by the Government’s interlocutory appeal may be weighed in determining whether a defendant has suffered a violation of his rights to a speedy trial. It is clear in this case, however, that respondents have failed to show a reason for according these delays any effective weight towards their speedy trial claims. There is no showing of bad faith or dilatory purpose on the Government’s part. The Government’s position in each of the appeals was strong, and the reversals by the Court of Appeals are prima facie evidence of the reasonableness of the Government’s action. Moreover, despite the seriousness of the charged offenses, the District Court chose not to subject respondents to any actual restraints pending the outcome of the appeals.
  The only remaining question is the weight to be attributed to delays caused by respondents’ interlocutory appeals. In that limited class of cases where a pretrial appeal by the defendant is appropriate, see, e. g., Hollywood Motor Car Co., supra, at 265-266, delays from such an appeal ordinarily will not weigh in favor of a defendant’s speedy trial claims. A defendant with a meritorious appeal would bear the heavy burden of showing an unreasonable delay caused by the prosecution in that appeal, or a wholly unjustifiable delay by the appellate court. A defendant who resorts to an interlocutory appeal normally should not be able upon return to the district court to reap the reward of dismissal for failure to receive a speedy trial. As one Court of Appeals has noted in the context of a District Court’s consideration of pretrial motions:
  “Having sought the aid of the judicial process and realizing the deliberateness that a court employs in reaching a decision, the defendants are not now able to criticize the very process which they so frequently called upon.” United States v. Auerbach, 420 F. 2d 921, 924 (CA5 1969), rehearing denied, 423 F. 2d 676, cert. denied, 399 U. S. 905 (1970).
  In the present case, respondents’ appeal was allowable under the law of the Ninth Circuit before our decision in Hollywood Motor Car, supra. But we find that their position was so lacking in merit that the time consumed by this appeal should not weigh in support of respondents’ speedy trial claim. Nor do we weigh the additional delay of six months resulting from respondents’ frivolous action in seeking rehearing and certiorari toward respondents’ speedy trial claim. See ibid., decided prior to these latter actions.
  > i — j
  We cannot hold, on the facts before us, that the delays asserted by respondents weigh sufficiently in support of their speedy trial claim to violate the Speedy Trial Clause. They do not justify the severe remedy of dismissing the indictment. Accordingly, the judgment of the Court of Appeals for the Ninth Circuit is reversed.
  It is so ordered.
  The Speedy Trial Clause of the Sixth Amendment reads: “In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial. . . .”
  The more stringent provisions of the Speedy Trial Act, 18 U. S. C. §3161 et seq., have mooted much litigation about the requirements of the Speedy Trial Clause as applied to federal prosecutions. The time devoted to pretrial appeals, however, is automatically excluded under the Act, §§ 3161(d)(2) and (h)(1)(E). These respondents must therefore seek any relief under the Speedy Trial Clause.
  Dennis James Banks, one of the respondents in this action, was active in the American Indian Movement, and was a fugitive when these events occurred. The siege and occupation of Wounded Knee had taken place 60 months before, and the Federal Bureau of Investigation was tracking Banks and his party as fugitives from that affair. United States v. Loud Hawk, 628 F. 2d 1139, 1141 (CA9 1979). For a description of the battle of Wounded Knee and the resultant violence and death, see United States v. Banks, 383 F. Supp. 389 (SD 1974), appeal dism’d, 513 F. 2d 1329 (CA8 1975); United States v. Banks, 374 F. Supp. 321 (SD 1974); United States v. Banks, 368 F. Supp. 1245 (SD 1973).
  The Government represents that it would introduce evidence at trial showing that respondent Dennis Banks was the driver of one of the vehicles. Banks was not apprehended until January 26, 1976.
  Respondents still dispute any characterization of the destroyed evidence as dynamite. Brief in Opposition 4, and n. 4; Brief for Respondents 4, n. 5. The Court of Appeals wrote:
  “Each of the seven boxes was marked ‘High Explosives Dangerous’ and on the side had the following markings:
  “‘50 lbs
  Gelex 2 1x8
  70% Strength
  D73MAO 7B’
  “together with the logo of the DuPont company prominently displayed. Inside were red cylindrical sticks with heavy wrapping paper covering the contents and marked:
  “ ‘Explosives Dangerous
  Gelex 2
  70% Strength
  E I Dupont De Nemours & Co. (Inc.).’”
  United States v. Loud Hawk, supra, at 1144-1146.
  We follow the practice of the opinions discussing the issue and refer to the destroyed evidence as dynamite. 741 F. 2d 1184, 1187 (CA9 1984); United States v. Loud Hawk, supra, at 1143. Cf. United States v. Banks, 682 F. 2d 841, 843 (CA9 1982) (“explosive material”).
  App. 40a-42a, and n. 4, 90a.
  The District Court denied the motion on January 21, 1976.
  On January 21, 1976, the District Court postponed trial until March 8, 1976, on respondents’ motion. On respondents’ motion and over the objection of the Government, on February 18, 1976, the District Court again continued trial until May 12, 1976. Record, Doc. Nos. 62, 64.
  The Government is permitted to pursue some interlocutory appeals under 18 U. S. C. § 3731. That section as then in effect read:
  “In a criminal case an appeal by the United States shall lie to a court of appeals from a decision, judgment, or order of a district court dismissing an indictment or information as to any one or more counts, except that no appeal shall lie where the double jeopardy clause of the United States Constitution prohibits further prosecution.
  “An appeal by the United States shall lie to a court of appeals from a decision or order of a district courts [sic] suppressing or excluding evidence or requiring the return of seized property in a criminal proceeding, not made after the defendant has been put in jeopardy and before the verdict or finding on an indictment or information, if the United States attorney certifies to the district court that the appeal is not taken for purpose of delay and that the evidence is a substantial proof of a fact material in the proceeding.
  “The appeal in all such cases shall be taken within thirty days after the decision, judgment or order has been rendered and shall be diligently prosecuted.
  “Pending the prosecution and determination of the appeal in the foregoing instances, the defendant shall be released in accordance with chapter 207 of this title.
  “The provisions of this section shall be liberally construed to effectuate its purposes.”
  App. 57. The Government obtained a new indictment from the grand jury that recharged with the original firearms count (although it substituted “receiving” for “transporting”) and two of the original three dynamite device counts. The new indictment also charged the defendants with two new destructive device counts relating to a slightly different type of destructive device. It also charged respondent KaMook Banks with a new count of receiving firearms while under indictment for a felony.
  A listing of the relevant docket entries, id., at 38-145, shows that the motions filed during this 4-week period included: motion for a transcript of a recently held hearing (June 24,1980), id., at 61; motion to dismiss counts three and four for insufficient allegations (July 7, 1980), id., at 63; motion to suppress evidence of pretrial photographic identification and “Tainted Potential Courtroom Identification,” ibid.; motion for change injury selection procedure, ibid.; motion to dismiss because of the grand jury composition, ibid.; motion to dismiss for vindictive prosecution, ibid.; motion to dismiss for preindictment delay, ibid.; motion for disclosure and production (July 21, 1980), id., at 64; motion for appointment of investigator at Government expense, ibid.; and third motion to dismiss for gross governmental misconduct, ibid. All motions except for KaMook Banks’ vindictive prosecution motion were denied (Aug. 5, 1980). Id., at 65-66.
  The Ninth Circuit’s holding conflicts with three other Circuits. See United States v. Herman, 576 F. 2d 1139, 1146 (CA5 1978); United States v. Jackson, 508 F. 2d 1001, 1004 (CA7 1975); United States v. Bishton, 150 U. S. App. D. C. 51, 54, 463 F. 2d 887, 890 (1972).
  In MacDonald, we held that where the Government has dismissed an indictment and the defendant is not subject to actual restraints on his liberty, the Speedy Trial Clause does not apply.
  In those instances where the defendant is subject to incarceration or bail, the courts would have to engage in a balancing of the restrictions imposed and their effect on the defendant, the necessity for delay, and the length of delay, using the approach we have outlined below. Infra, at 315-316.
  Homer, The Odyssey, Book II, lines 91-105 (R. Lattimore trans. 1965).