WOLLMAN, Circuit Judge.
In In re Department of Justice, 950 F.2d 530 (8th Cir.1991) (Crancer I), a panel of this court upheld the district court’s order requiring the government to provide a Vaughn1 index after the government had invoked Exemption 7(A) of the Freedom of Information Act, 5 U.S.C. § 552(b)(7)(A) (1988). We granted the government’s suggestion for rehearing en banc and vacated the panel’s decision. We now issue a writ of mandamus, vacate the challenged order, and remand the case to the district court for further proceedings.
I.
In 1987, Barbara Ann Crancer filed a Freedom of Information Act (FOIA) request with the Department of Justice. Crancer sought the release of certain information uncovered during the investigation conducted by the Federal Bureau of Investigation into the disappearance of her father, Jimmy Hoffa, the former president of the International Brotherhood of Teamsters. The FBI’s investigation has resulted in the accumulation of more than 13,800 pages of records relating to Hoffa’s disappearance.
The Department denied Crancer’s request on the basis of Exemption 7(A), contending that the Hoffa FBI file contains “records or information compiled for law enforcement purposes,” the release of which “could reasonably be expected to interfere with enforcement proceedings.” 5 U.S.C. § 552(b)(7)(A).
After exhausting her administrative remedies, Crancer brought suit to compel the Department to provide her with the documents she had requested. During the pen-dency of her suit, Crancer filed a second, broader request seeking any and all materials relating to the FBI’s investigation into Hoffa’s disappearance. After this request was administratively denied by the Department, also on the basis of Exemption 7(A), Crancer amended her complaint to include her second request.
The Department moved for summary judgment on the basis of the claimed exemption. The district court ordered the Department to provide Crancer with a Vaughn index so that she could effectively oppose the government’s pending motion. The court’s order required the Department to produce an “itemized, indexed inventory of every agency record or portion thereof responsive to plaintiffs FOIA request,” together with a “detailed justification statement covering each refusal to release [an] agency record[] or portions thereof.” D.Ct. Order of July 27, 1990, at 1. The Department asked the court to reconsider its order directing the production of the Vaughn index. This request was denied. The Department then requested that the district court modify its earlier order and allow the Department to provide a categorical description of the documents contained in the Hoffa FBI file. The Department submitted a list of nine categories of documents and an affidavit describing the potential interference with enforcement proceedings that would result if it were required to compile a Vaughn index. The district court denied this request and ordered the Department to submit the Vaughn index to a magistrate judge for in camera review.
In lieu of submitting a Vaughn index, the Department asked the magistrate judge to review the actual documents in camera. The magistrate judge denied this request, but extended the time period in which the Vaughn index was to be submitted. The Department then asked the district court to [1305]*1305reconsider the magistrate judge’s order or, in the alternative, to certify the matter for interlocutory appeal. These requests were also denied.
The Department then sought relief from this court, asserting jurisdiction under the collateral order doctrine, Cohen v. Beneficial Indus. Loan Corp., 337 U.S. 541, 69 S.Ct. 1221, 93 L.Ed. 1528 (1949), or the All Writs Act, 28 U.S.C. § 1651(b).
In Crancer I, the panel asserted jurisdiction under the All Writs Act and upheld the district court’s order requiring the preparation of a Vaughn index. The panel first determined that the Department could not be required to provide a specific factual showing and explanation describing why each document is exempt. It went on to hold, however, that the Department could be required to make a specific factual showing to demonstrate why each document belongs in a certain category, along with an explanation describing why the category itself is exempt from disclosure.
II.
We first examine whether, and the basis upon which, we have jurisdiction to hear this case.
We possess discretionary writ-issuing authority under the All Writs Act, 28 U.S.C. § 1651(b). As noted by the panel in Crancer I, mandamus is “available only in those exceptional circumstances amounting to a judicial usurpation of power.” In re Ford Motor Co., 751 F.2d 274, 275 (8th Cir.1984).
The panel determined that:
[The Department’s] argument is a novel one and has not been directly addressed by any court. If [the Department] is correct in its contention that the district court lacked authority to order a Vaughn index, then a writ would be the proper remedy. Because the issue of whether the writ is available is intertwined with the merits of this interlocutory matter, we must decide whether the district court had authority to require a Vaughn-type index in these circumstances.
Crancer I, 950 F.2d at 532 (citation omitted). We agree with the panel’s analysis and believe that this case presents a unique situation. Thus, we conclude that we have jurisdiction to decide the question whether the district court’s order directing the Department to produce a Vaughn index in the face of the Department’s invocation of Exemption 7(A) constituted a judicial usurpation of power.
III.
“The basic purpose of FOIA is to ensure an informed citizenry, vital to the functioning of a democratic society, needed to check against corruption and to hold the governors accountable to the governed.” NLRB v. Robbins Tire & Rubber Co., 437 U.S. 214, 242, 98 S.Ct. 2311, 2327, 57 L.Ed.2d 159 (1978). Consistent with this policy of broad disclosure, the government is required to release all requested information upon the demand of any member of the public. Id. at 221, 98 S.Ct. at 2316; see also Curran v. Department of Justice, 813 F.2d 473 (1st Cir.1987); Irons v. FBI, 811 F.2d 681, 685 (1st Cir.1987). Congress fashioned certain explicit exemptions from disclosure, however, in order to preserve vital government policies and, in some cases, to protect individuals. See 5 U.S.C. § 552(b)(1)—)9; see also Robbins Tire, 437 U.S. at 220-21, 98 S.Ct. at 2316 (“Congress carefully structured nine exemptions from the otherwise mandatory disclosure requirements in order to protect specified confidentiality and privacy interests.”).
Once information is requested under FOIA, therefore, the government must provide the information unless it determines that a specific exemption applies. Likewise, the government bears the burden of demonstrating that the claimed exemption applies. 5 U.S.C. § 552(a)(4)(B). The district court must determine de novo whether the government has satisfied its burden. Id.
In the face of a claimed statutory exemption, district courts have sometimes required the government to provide a Vaughn index. “This indexing procedure is perceived as necessary to permit the district court and the requesting party to evaluate the [government’s] decision to withhold records and to ensure its compliance with the mandates of the FOIA.” Barney v. IRS, 618 F.2d 1268, 1272 (8th Cir.1980) (per curiam).
[1306]*1306A Vaughn index provides a specific factual description of each document sought by the FOIA requester. Specifically, such an index includes a general description of each document’s contents, including information about the document’s creation, such as date, time, and place. Crancer I, 950 F.2d at 533. “For each document, the exemption claimed by the government is identified, and an explanation as to why the exemption applies to the document in question is provided.” Id.; see also Barney, 618 F.2d at 1272.
Exemption 7(A) of FOIA provides that the act “does not apply to matters that are — * * * (7) records or information compiled for law enforcement purposes, but only to the extent that the production of such law enforcement records or information (A) could reasonably be expected to interfere with enforcement proceedings!)]” 5 U.S.C. § 552(b)(7)(A). The government contends that the courts have interpreted this exemption differently from other FOIA exemptions, with the result that a district court may not order the production of a Vaughn index when Exemption 7(A) is invoked.
In NLRB v. Robbins Tire & Rubber Co., 437 U.S. 214, 98 S.Ct. 2311, 57 L.Ed.2d 159 (1978), the Supreme Court addressed the burden that the government must bear when asserting Exemption 7(A). In that case, the FOIA requester, an employer, sought from the National Labor Relations Board all statements made by potential witnesses prior to a Board hearing on the employer’s unfair labor practices. Id. at 216, 98 S.Ct. at 2314. On appeal, the employer argued that the district court had erred by not requiring the government to make an individualized showing that each withheld document fit within the limits of Exemption 7(A). The Supreme Court rejected this argument, interpreting Exemption 7(A) of FOIA to require the government to prove that “with respect to particular kinds of enforcement proceedings, disclosure of particular kinds of investigatory records while a case is pending would generally ‘interfere with enforcement proceedings.’ ” Id. at 236, 98 S.Ct. at 2324.
In support of its ruling, the Supreme Court noted that:
[t]here is a readily apparent difference between [Exemption 7(A) ] and [Exemptions 7(B)-(D)]. The latter [exemptions] refer to particular cases ... and thus seem to require a showing that the factors made relevant by the statute are present in each distinct situation. By contrast, since [Exemption 7(A) ] speaks in the plural voice about “enforcement proceedings,” it appears to contemplate that certain generic determinations might be made.
437 U.S. at 223-24, 98 S.Ct. at 2318. The Court then examined Exemption 7’s legislative history, which appeared to confirm the Court’s observation regarding the distinguishing characteristic of Exemption 7(A). Id. at 224-34, 98 S.Ct. at 2318. The Court further noted that had Congress intended that “the Government in each case show a particularized risk to its individual ‘enforcement proceeding],’ ” it could have done so. Id. at 234, 98 S.Ct. at 2323.
The Court also addressed Congress’s 1974 amendment of Exemption 7(A). This amendment was designed “to eliminate ‘blanket exemptions’ for Government records simply because they were found in investigatory files compiled for law enforcement purposes.” Id. at 236, 98 S.Ct. at 2324. The Court’s discussion of President Ford’s veto of the 1974 amendment and the subsequent congressional override is instructive for our present analysis. The President was concerned that the 1974 amendment to Exemption 7(A) “would require the Government to ‘prove .. . — separately for each paragraph of each document — that disclosure “would” cause’ a specific harm” to enforcement proceedings. Id. at 235, 98 S.Ct. at 2323 (citation omitted). Congressional supporters of the amendment termed the President’s interpretation of the amendment “‘ludicrous,’” stating that the “ ‘burden is substantially less than we would be led to believe by the President’s message.’ ” Id. (citation omitted).2
The Court concluded that although the 1974 amendment to Exemption 7(A) was de[1307]*1307signed to eliminate blanket exemptions for records found in investigatory files, Congress did not intend that generic determinations of those materials entitled to Exemption 7(A) protection could never be made. Rather, the government must demonstrate, and courts must determine, whether “disclosure of particular kinds of investigatory records ... would generally ‘interfere with enforcement proceedings.’ ” Id. at 236, 98 S.Ct. at 2324. In other words, Congress intended that certain types or categories of investigatory records be withheld under Exemption 7(A) because disclosure of documents within those categories generally would interfere with enforcement proceedings.
With this understanding, post-Robbins Tire courts have made these determinations generically, category-of-document by category-of-document. In Barney v. IRS, for example, we were confronted with the question whether, in the wake of Robbins Tire, the government was required to provide a Vaughn index after the government invoked Exemption 7(A). 618 F.2d 1268 (8th Cir.1980) (per curiam). We held that “[t]o sustain its burden of showing documents were properly withheld under exemption 7(A) the government had to establish only that they were investigatory records compiled for law enforcement purposes and that production would interfere with pending enforcement proceedings.” Id. at 1272-73. The Barney court bolstered its conclusion by emphasizing that “[u]nder exemption 7(A) the government is not required to make a specific factual showing with respect to each withheld document that disclosure would actually interfere with a particular enforcement proceeding.” Id. at 1273 (citing Robbins Tire, 437 U.S. at 234-35, 98 S.Ct. at 2323).
Congress amended Exemption 7 in 1986 to lessen the burden on the government in establishing the application of Exemption 7(A). Freedom of Information Reform Act of 1986 (FIRA), Pub.L. No. 99-570, § 1802, 100 Stat. 3207, 3207-48 (1986). Whereas under the 1974 version of Exemption 7(A), the government bore the burden of showing that the production of the requested law enforcement records “would interfere with enforcement proceedings,” under the 1986 version "the government need only show that the production of law enforcement records or information “could reasonably be expected to interfere with law enforcement proceedings.”
In 1989, the Supreme Court revisited the government’s burden under Exemption 7, this time focusing on the use of categorical determinations under Exemption 7(C), which covers documents whose production “could reasonably be expected to constitute an unwarranted invasion of personal privacy.” United States Dep’t of Justice v. Reporters Comm. for Freedom of the Press, 489 U.S. 749, 109 S.Ct. 1468, 103 L.Ed.2d 774 (1989) (“Reporters Committee ”). In Reporters Committee, a group of journalists requested that the FBI disclose an individual’s computerized criminal history file, known colloquially as the person’s “rap sheet.” The Supreme Court held that the production of rap sheets “as a categorical matter” could reasonably be expected to constitute an unwarranted invasion of a citizen’s privacy. Id. at 780, 109 S.Ct. at 1485.
The Court discussed its earlier approval of a categorical approach to Exemption 7(A) in Robbins Tire. The Court noted that it had based its ruling in Robbins Tire on the perception that Exemption 7(A)’s reference to the plural “enforcement proceedings” supported a categorical approach when 7(A) was invoked, in contrast to the singular references in the other subsections of Exemption 7, which seemed to suggest a case-by-case balancing. Finding that “[jjust as one can ask whether a particular rap sheet is a ‘law enforcement record’ that meets the requirements of [Exemption 7(C) ], so too can one ask whether rap sheéts in general ... are ‘law enforcement records’ that meet the stated criteria,” the Court concluded that its approval of a categorical approach for Exemption 7(A) applied with equal force to the other subsections in Exemption 7. Id. at 779, 109 S.Ct. at 1485. Because the Court found that the disclosure of computerized compilations of an individual’s criminal history could always be expected to constitute an invasion of an individual’s privacy, it held that rap sheets as a category are exempted from disclosure under FOIA. Id. at 780, 109 S.Ct. at 1485.
The Court also supported its holding that a categorical approach was appropriate for Exemption 7(C) as well as 7(A) by pointing to [1308]*1308the 1986 amendment. The Court stated that the amended 7(C), which like 7(A) had changed from the more stringent “would” to the more flexible “could reasonably be expected to,” was enacted “to give the Government greater flexibility in responding to FOIA requests for law enforcement records or information.” Id. at 777 n. 22, 109 S.Ct. at 1484 n. 22. The Court further noted that the amendment was designed to “replace a focus on the effect of a particular disclosure ‘with a standard of reasonableness ... based on an objective test.’ ” Id. This reasonableness standard, the Court concluded, “amply supports a categorical approach to the balance of private and public interests in Exemption 7(C).” Id. The Court’s conclusion concerning the effect of the amendment applies with equal force to Exemption 7(A), given the Court’s conclusion that all of the Exemption 7 subsections should be interpreted similarly with respect to the use of categorical justifications.
Recently, the Court further explained its categorical approach in United, States Dep’t of Justice v. Landano, — U.S. -, 113 S.Ct. 2014, 124 L.Ed.2d 84 (1993). Seeking to support a claim that the government had failed to disclose exculpatory evidence in his earlier criminal case, Landano sought all of the FBI flies connected with the police officer’s murder for which Landano had been convicted. After releasing a portion of its files, the FBI withheld certain documents on the grounds that they were exempt under Exemption 7(D), which applies to law enforcement records or information whose production “could reasonably be expected to disclose the identity of a confidential source.” The district court largely rejected the government’s categorical explanations and held that the FBI had to articulate “case-specific reasons for non-disclosure” of all information other than records pertaining to regular FBI informants. Id., — U.S. at -, 113 S.Ct. at 2018. The Court of Appeals for the Third Circuit affirmed, holding that the government had to provide detailed explanations relating to each alleged confidential source in order to justify nondisclosure under Exemption 7(D). Id., — U.S. at -, 113 S.Ct. at 2019.
The Supreme Court reversed and remanded. The Court first rejected the government’s argument that it is entitled to a presumption under FOIA that all FBI sources are confidential and that any records relating to FBI sources should be presumptively exempt from disclosure. The Court noted that the government’s proposed presumption was not rebuttable, as argued by the government, but amounted to an irrebuttable presumption or blanket exemption that found no support in the language or legislative history of Exemption 7(D). Id., — U.S. at -, 113 S.Ct. at 2023.
The Court, however, did not agree with the Third Circuit’s requirement that the government must provide a detailed justification relating to each alleged confidential source. To the contrary, the Court stated that the government could point to categories of documents, the circumstances surrounding which would support the inference that the sources to whom they pertained were confidential. Id., — U.S. at -, 113 S.Ct. at 2023. For example, the Court suggested that “paid informants normally expect their cooperation with the FBI to be kept confidential,” implying that the government need only present a category of documents relating to paid informants, whose production could reasonably be expected to disclose the informant’s identity, in order to justify nondisclosure under Exemption 7(D). Id. As a second example, the Court opined that eyewitnesses to a gang-related murder could also probably be presumed to be confidential. Id. The Court concluded that such a generic, categorical approach best articulated Congress’s intent “to provide ‘ “ ‘workable’ rules” ’ of FOIA disclosure.” Id. (citing Reporters Committee, 489 U.S. at 779, 109 S.Ct. at 1485).
Thus, we conclude that the Supreme Court has consistently interpreted Exemption 7 of FOIA (specifically so far subsections 7(A), 7(C), and 7(D)) to permit the government to proceed on a categorical basis in order to justify nondisclosure under one of Exemption 7’s subsections. See Landano, — U.S. at —-—, 113 S.Ct. at 2023-24; Reporters Committee, 489 U.S. at 779-80, 109 S.Ct. at 1485; Robbins Tire, 437 U.S. at 241-43, 98 S.Ct. at 2326-27. The Court’s interpretation [1309]*1309of Exemption 7 and Congress’s intent in enacting it has been strengthened by the 1986 amendment, which provided for greater flexibility and lessened the government’s burden. See Reporters Committee, 489 U.S. at 777 n. 22, 109 S.Ct. at 1484 n. 22.
Our interpretation of Exemption 7(A) in Barney mirrors the Supreme Court’s interpretation. Moreover, consistent with the teachings of Robbins Tire, our analysis in Barney is in accord with the principle that “ ‘the inherent nature of the requested documents is irrelevant to the question of exemption.’ ” Curran, 813 F.2d at 474 (quoting Irons v. FBI, 811 F.2d 681, 685 (1st Cir.1987)). This interpretation is consistent with decisions from other circuits. See, e.g., Lewis v. IRS, 823 F.2d 375, 378 (9th Cir.1987); Curran, 813 F.2d at 475; Church of Scientology of Calif. v. IRS, 792 F.2d 146, 152 (D.C.Cir.1986); Campbell, 682 F.2d at 265.3
The District of Columbia Circuit, which originally developed the Vaughn index, has succinctly explained the relationship between Exemption 7(A), as interpreted by Robbins Tire, and the use of Vaughn indices:
[w]hen ... a claimed FOIA exemption consists of a generic exclusion [such as Exemption 7(A) ], dependent upon the category of records rather than the subject matter which each individual record contains, resort to a Vaughn index is futile. Thus, in NLRB v. Robbins Tire & Rubber Co., [citation omitted], the Supreme Court upheld, without any provision of a Vaughn index, the Labor Board’s refusal to provide under FOIA witness statements obtained in the investigation of pending unfair labor practice proceedings. A Vaughn index would have served no purpose since ... [Exemption 7(A) ] did not require a showing that each individual document would produce such interference, but could rather be applied generically, to classes of records such as witness statements.
Church of Scientology, 792 F.2d at 152 (Scalia, J.).
In light of the above discussion, the district court’s order for a Vaughn index in the present case appends an additional requirement to Exemption 7(A) that exceeds the bounds of the statute as interpreted by the Supreme Court and this court. The district court’s order required the government, after identifying each document, to provide a “detailed justification statement covering each refusal to release said agency records or portions thereof.” D.Ct. Order of July 27, 1990, at 1. This goes beyond the categorical explanations that the Supreme Court in Robbins Tire held to be sufficient to justify nondisclosure under Exemption 7(A).
In sum, the government bears the burden of establishing that Exemption 7(A) applies. And under Robbins Tire, Exemption 7(A) does not require that the government produce a fact-specific, document-specific, Vaughn index in order to satisfy that burden. The contents of the requested documents are irrelevant. It is the particular categories of documents, and the likelihood that the release of documents within those categories could reasonably be expected to threaten enforcement proceedings, on which the court must focus. The district court, therefore, acted beyond the scope of its authority when it ordered the Department to produce a Vaughn index.
IV.
“Although generic determinations are permitted, and the government need not justify its 7(A) refusal on a doeument-by-document basis, there must nevertheless be some minimally sufficient showing.” Curran, 813 F.2d at 475. To satisfy its burden with regard to Exemption 7(A), the government must define functional categories of doeu-[1310]*1310ments; it must conduct a doeument-by-document review to assign documents to proper categories; and it must explain to the court how the release of each category would interfere with enforcement proceedings.4 See Bevis v. Department of State, 801 F.2d 1386, 1389 (D.C.Cir.1986).
If the generic index submitted by the government is not sufficient to sustain the 7(A) exemption, then the district court may request more specific, distinct categories so that it may more easily determine how each category might interfere with enforcement proceedings. See Campbell, 682 F.2d at 265. Indeed, this is what the court ordered in Bevis, 801 F.2d at 1390. “The chief characteristic of an acceptable taxonomy should be functionality—that is, the classification should be clear enough to permit a court to ascertain ‘how each .. category of documents, if disclosed, would interfere with the investigation.’” Curran, 813 F.2d at 475 (citing Campbell, 682 F.2d at 265).
If the categories remain too general, the district court may also examine the disputed documents in camera to make a first hand determination. 5 U.S.C. § 552(a)(4)(B); Lewis, 823 F.2d at 378; see also Cleary v. FBI, 811 F.2d 421, 423 (8th Cir.1987) (in camera examination in 7(C) and (D) exemption case); Parton v. United States Dep’t of Justice, 727 F.2d 774 (8th Cir.1984); Cox v. United States Dep’t of Justice, 576 F.2d 1302 (8th Cir.1978).
In Dickerson v. Department of Justice, 992 F.2d 1426 (6th Cir.1993), the plaintiff sought the release of information from the Hoffa FBI file and requested a Vaughn index. The district court accepted the government’s categorical index, examined certain documents in camera, and granted summary judgment to the government on the basis of Exemption 7(A). The court stated that it was “satisfied beyond any doubt that the investigation into Hoffa’s disappearance is active and continuing, with the clear direction of future erimi-nal proceedings being instituted.” Dickerson v. Department of Justice, No. 90-CV-60045-AA, 1991 WL 337422 (E.D.Mich. July 31, 1991).
On appeal, the Court of Appeals for the Sixth Circuit reviewed the file that had been submitted to the district court and concluded that the district court had not abused its discretion in ruling that there was no need to go beyond the documents that the FBI had submitted. Dickerson, 992 F.2d at 1431-32. The court of appeals also held that the district court was correct in finding that the FBI’s investigation remains active and that it was directed toward the institution of criminal proceedings. Id. at 1432. Further, the Sixth Circuit held that the district court was correct “in its finding that production of the records sought by plaintiff Dickerson could reasonably be expected to interfere with a future prosecution.” Id. at 1433.
In the present case, the district court was apparently of the belief that the Department was not asserting Exemption 7(A) in good faith or that it had not individually reviewed the requested documents to place them in their functional categories. While the district court may not order a Vaughn index as an aid to its review, it still must satisfy itself that the requested documents have been properly withheld. The Department’s failure to demonstrate that the sought-after documents relate to an ongoing investigation or could reasonably be expected to interfere with future law enforcement proceedings will carry with it the loss of the 7(A) exemption. In that regard, we note that although the Sixth Circuit’s affirmative holding on that issue in Dickerson will not be binding on the district court on remand, that holding does give credence to the Department’s assertion of the 7(A) exemption in the present case.
In summary, Congress enacted Exemption 7(A) to prohibit interference in an ongoing criminal investigation. The Supreme Court’s decision in Robbins Tire to allow generic category-by-category classifications in Exemption 7(A) cases, rather than detailed fact-[1311]*1311specific explanations on a document-by-document basis, serves an important interest: “[provision of the detail which a satisfactory Vaughn Index entails would itself probably breach the dike.” Curran, 813 F.2d at 475. “Withal, a tightrope must be walked [in Exemption 7(A) cases]: categories must be distinct enough to allow meaningful judicial review, yet not so distinct as prematurely to let the cat out of the investigative bag.” Id. In short, we will not allow the cure, Exemption 7(A), to “become the carrier of the disease.” Id.
The writ of mandamus prayed for is issued. The orders directing the production of a Vaughn index are vacated, and the case is remanded to the district court for further proceedings consistent with this opinion.