Petitioner Alberto Noriega-Perez appeals from a summary decision of an Administrative Law Judge (ALJ) imposing a monetary fine for civil document fraud. The civil action was commenced after Noriega-Perez had entered a plea of guilty to conspiracy to possess forged, counterfeit, and false documents. The summary decision is affirmed.
I. Background
On December 2, 1992, Noriega-Perez was indicted in the District Court for the Southern District of California for conspiracy to possess forged, counterfeit, and false immigration documents. Thereafter, Noriega-Perez entered a plea of guilty to one count of “Conspiracy to Possess Forged, Counterfeit, and False Documents” in violation of 18 U.S.C. §§ 371 and 1546. The district court accepted the guilty plea, fined Noriega-Perez $20,000, and sentenced him to 18 months of imprisonment, followed by three years of supervised release. Noriega-Perez did not file an appeal, but his sentence was reduced in June 1994 to time served and the fine reduced to $5,000 pursuant to a petition for a writ of habeas corpus.
Two months after Noriega-Perez’s guilty plea, the Immigration and Naturalization Service (INS) issued a Notice of Intent to Fine (Notice) him for civil document fraud in violation of 8 U.S.C. § 1324c. The conduct alleged in the Notice-forging temporary immigration documents and possessing fraudulent immigration forms and social security cards-was related to the conduct that underlaid Noriega-Perez’s guilty plea for conspiracy to commit document fraud. The INS sought to order Noriega-Perez to cease and desist from his unlawful action and to pay a “civil money penalty” of $176,000. Noriega-Perez filed a pro se response to the INS asserting that he had already been sentenced for the wrongful acts alleged in the Notice.
On January 23, 1995, the INS filed a two-count complaint with the Executive Office for Immigration Review (EOIR), Office of the Chief Administrative Hearing Officer (OCAHO), charging Noriega-Perez with document fraud pursuant to 8 U.S.C. § 1324c. The complaint alleged the same violations contained in the Notice and requested $96,000 in civil money penalties. Specifically, the United States charged that Noriega-Perez violated the Immigration and Nationality Act, 8 U.S.C. § 1324c, by (1) forging eight temporary immigration documents, (2) possessing 298 fraudulent INS Forms 1-94, (3) possessing 21 fraudulent U.S. Social Security cards, and (4) possessing one fraudulent INS Form I-151. In his pro se response to the complaint, Noriega-Perez denied the allegations and affirmatively asserted, as one of multiple grounds for relief, that the fine constituted a second punishment for the same crime.
After a series of discovery motions and rulings, on October 27, 1995, the ALJ granted the INS’s motion for summary decision on the merits. The ALJ then ordered the parties to submit briefs recommending appropriate penalties and addressing Noriega-Perez’s claim that imposition of the fine would constitute double jeopardy.
In its brief to the ALJ, the INS sought a $96,000 fine. The INS based the fine amount on a memorandum prepared by special agent Alejandro Kastner of the Investigation Unit of the San Diego INS district office. Agent Kastner reported that the investigation of Noriega-Perez and his alleged coconspirators involved many hours of investigation by numerous units. The total cost of the investigation was approximately $48,000. The INS also denied that the imposition of a civil fine after the government had already imposed criminal punishment implicated the double jeopardy clause.
On November 15, 1995, Noriega-Perez filed a motion in response to the ALJ’s request for additional briefing. He raised several arguments against the judgment including his previously-raised double *1170jeopardy claim and further asserted that the ALJ lacked subject-matter jurisdiction because ALJs are not Article III judges. Noriega-Perez also indicated that he could not recommend an appropriate penalty pursuant to the ALJ’s order because he did not have sufficient information.
The ALJ issued his Final Decision and Order on March 2, 1996. The ALJ considered a number of factors before imposing a fine of $96,000. He considered Noriega-Perez’s monetary motivation, failure to offer mitigating factors, and prior conviction for transferring counterfeit Federal Reserve notes. He also ordered Noriega-Perez to cease and desist from engaging in future document fraud.
In response to Noriega-Perez’s legal arguments, the ALJ noted that the jurisdictional argument was not properly before him because the enabling statute did not give him the power to dismiss actions based on constitutional infirmities. Additionally, the ALJ found that under United States v. Halper, 490 U.S. 435, 109 S.Ct. 1892, 104 L.Ed.2d 487 (1989), the fine was remedial in nature and therefore did not violate the double jeopardy clause.
Noriega-Perez now appeals from the ALJ’s final order. Although he raises many issues, only the double jeopardy claim and the Article III claim merit discussion.1
II. Statutory Scheme
In an attempt to reduce the flow of illegal immigration into the United States, Congress enacted the Immigration Reform and Control Act of 1986 (IRCA). The purpose of IRCA was to “close the back door on illegal immigration so that the front door on legal immigration may remain open.” See H.R.Rep. No. 101-723(i), at 46 (1986), reprinted in 1986 U.S.C.C.A.N. 5649, 5649-5650. Because it believed that “[ejmployment is the magnet that attracts aliens here illegally,” id., Congress made it unlawful for an employer knowingly to hire an unauthorized alien to work in the United States. See 8 U.S.C. § 1324a. IRCA also established an employment verification system which required employers to examine various documents establishing eligibility of employment, and to retain a verification form establishing the employee’s eligibility. See 8 U.S.C. §§ 1324a(b)(l), (2), and (3).
In 1990, Congress strengthened IRCA by enacting 8 U.S.C. § 1324c. Section 1324c establishes a monetary penalty for those who knowingly forge an employment eligibility document, or use or possess such a falsely made document, in order to meet, *1171or enable another person to meet, the employment eligibility requirements of chapter 12, Title 8 of the United States Code. See 8 U.S.C. §§ 1324c(a), (c)(3). Section 1324c grants the adjudication of cases arising under it to ALJs. See 8 U.S.C. §§ 1324c(d)(2), (5).
III. Double Jeopardy
The Fifth Amendment to the United States Constitution provides that no person shall “be subject for the same of-fence to be twice put in jeopardy of life or limb.” U.S. Const, amend. V. Noriega-Perez asserts that his conviction followed by his civil fine violated the double jeopardy clause. We disagree.
The facts are undisputed. On May 10, 1993, Noriega-Perez entered a guilty plea to conspiracy to commit document fraud under the general conspiracy statute, 18 U.S.C. § 371. Thereafter, on May 2, 1996, Noriega-Perez was fined for document fraud pursuant to 8 U.S.C. § 1324c(a)(l)-(2). Noriega-Perez claims that under the standard announced in Hudson v. United States, 522 U.S. 93, 118 S.Ct. 488, 139 L.Ed.2d 450 (1997), the civil fine actually constituted a form of criminal punishment. Accordingly, he -maintains, he could not be fined after having been convicted for the same acts.
Whether the civil penalty should be denominated criminal under Hudson is irrelevant, however, to resolving Noriega-Perez’s double-jeopardy claim if the previous criminal conviction was for a different offense. See id. at 493 (“The [Double Jeopardy] Clause protects only against the imposition of multiple criminal punishments for the same offense.” (emphasis omitted)). That is the case here; Noriega-Perez was first convicted of conspiracy to commit document fraud, not document fraud itself. Subsequently, his civil penalty was assessed for document fraud, not conspiracy to commit document fraud. It is clear that no double jeopardy violation occurred because conspiracy to commit an offense and the offense itself are separate offenses that can be tried separately. See United States v. Felix, 503 U.S. 378, 390-91, 112 S.Ct. 1377, 118 L.Ed.2d 25 (1992); Garrett v. United States, 471 U.S. 773, 778, 105 S.Ct. 2407, 85 L.Ed.2d 764 (1985); United States v. Saccoccia, 18 F.3d 795, 798 (9th Cir.1994); United States v. Hoelker, 765 F.2d 1422, 1427 (9th Cir.1985); United States v. Brooklier, 637 F.2d 620 (9th Cir.1981).2
Double jeopardy protections guarantee that the United States may not criminally-punish Noriega-Perez twice for the same offense. The threshold question for double jeopardy purposes is whether the two offenses for which Noriega-Perez was punished are the same. They are not. Even if Noriega-Perez’s fine imposed pursuant to section 1324c constituted a criminal penalty under Hudson, the double jeopardy clause is not violated.
IV. Separation of Powers
Congress entrusted the adjudication of document fraud cases under section 1324c to ALJs. See 8 U.S.C. § 1324c(d)(2). See also 28 C.F.R. § 68 et seq. Noriega-Perez claims that this grant of jurisdiction violates the separation of powers because an Article III judge did not preside over his ease. The issue of whether section 1324c’s grant of jurisdiction to an ALJ violates the separation of powers involves a two-part inquiry into (1) whether the fine provided for in the statute is civil or criminal in nature, and (2) considering the nature of the fine, whether the grant of jurisdiction to an ALJ is constitutional.
A. Hudson Inquiry
Although the Hudson analysis of whether the fine at issue is civil or criminal in nature need not be reached in address*1172ing Noriega-Perez’s double jeopardy-claim, it must guide our discussion of his Article III claim because the classification of a sanction imposed by an ALJ as civil in nature is highly probative, although not necessarily determinative, of the constitutionality of the ALJ’s jurisdiction.3 Under Hudson, the first inquiry is whether the legislature “in establishing the penalizing mechanism, indicated either expressly or impliedly a preference for one label or another.” 118 S.Ct. at 493 (quoting United States v. Ward, 448 U.S. 242, 248, 100 S.Ct. 2636, 65 L.Ed.2d 742 (1980)). Congressional intent is clear here. Congress labeled section 1324c a civil sanction. See 8 U.S.C. § 1324c(d)(3) (classifying the sanction as a “civil money penalty”).
Even where the legislature has indicated an intention to establish a civil penalty, whether the statutory scheme was “so punitive either in purpose or effect as to transform what was clearly intended as a civil remedy into a criminal penalty” must nevertheless be considered. Hudson, 118 S.Ct. at 493 (internal quotations and citations omitted). The legislative label of section 1324c will govern, however, unless seven “useful guideposts” show by the clearest proof that the civil penalty is so punitive that it is actually criminal in nature. Id.
The seven guideposts are whether the sanction (1) involves an affirmative disability or restraint, (2) has historically been treated as a criminal punishment, (3) requires a showing of scienter, (4) promotes the traditional aims of criminal punishment-retribution and deterrence, (5) applies to behavior which is already a crime, (6) has an alternative non-criminal purpose, and (7) is not excessive in relation to the alternative purposes. Id. We consider each in turn.
Affirmative Disability or Restraint
Monetary fines do not constitute an affirmative disability or restraint. See Hudson, 118 S.Ct. at 496. Although Noriega-Perez was also ordered to “cease and desist” his unlawful acts, this even more clearly does not fall within “affirmative restraint.” Id. Nor does it constitute a disability as that term has been viewed historically for Hudson purposes. Accordingly, neither imprisonment, nor its equivalent, was imposed on Noriega-Perez.
Historical Treatment
Monetary fines have not “historically been viewed as punishment.” Hudson, 118 S.Ct. at 495. “[T]he payment of fixed or variable sums of money ... ha[s] been recognized as enforceable by civil proceedings since the original revenue law of 1789.” Id. at 496 (citation omitted). In particular, monetary penalties for violations of immigration regulation, whether imposed on individuals or regulated companies, have historically been treated as civil in nature. See Hepner v. United States, 213 U.S. 103, 109-10, 29 S.Ct. 474, 53 L.Ed. 720 (1909) (“a civil action is an appropriate mode of proceeding” to collect a monetary penalty for knowingly inducing an alien “to migrate to the United States for the purpose of performing labor here”); United States v. Atlantic Fruit Co., 206 F. 440, 440-42 (2d Cir.1913) (a civil fine could *1173be maintained pursuant to a statute requiring steamship companies to post immigration laws); Millon v. United States, 219 F. 186, 186 (2d Cir.1914) (the government may impose a monetary penalty in a civil action for “knowingly assisting ... the migration or importation of any contract laborer into the United States”).
Document fraud in the immigration context has been punishable since 1924. The 1924 statute criminalized the forging of reentry permits and levied fines of up to $10,000. See Act, ch. 190, § 21, 62 Stat. 862 (1924). The 1952 revision of the statute, codified at 18 U.S.C. § 1546, criminalized the fraud and misuse of visas, permits, and other immigration documents. Section 1546 provides that an individual convicted of immigration fraud shall be fined not more than $2,000, imprisoned up to five years, or both. In 1986, the potential fine for immigration fraud was increased to $250,000. Congress did not classify as civil a fine for immigration-related document fraud until 1990, when Congress enacted the statute at issue here, 8 U.S.C. § 1324c.
For the majority of its existence the criminal statute punishing document fraud allowed for the imposition of imprisonment as well as a fine. Section 1324c, however, provides only for the imposition of a fine. In Hudson, the Supreme Court resolved a similar situation. The criminal counterparts to the civil sanction at issue in that ease also provided for fines, imprisonment, or both. See 18 U.S.C. §§ 371, 656, and 1005. Nevertheless, the Court found that the sanction at issue was historically civil. Accordingly, the historical treatment of the sanction imposed by section 1324c indicates that it is civil in nature.
Scienter
The conduct prohibited requires a showing of scienter, which is a traditional requirement of criminal liability, before sanctions may be imposed. Section 1324e(a) prohibits a party from “knowingly” engaging in the specified conduct. This factor tends to support Noriega-Perez’s claim that the fine is criminal in nature.
Traditional Aims of Punishment
The traditional aims of criminal punishment are retribution and deterrence. There is no indication that section 1324c’s provision for civil fines is intended to promote retribution, although as the government concedes, it is intended to have a deterrent effect. Although section 1324c may promote deterrence, “the mere presence of this purpose is insufficient to render a sanction criminal, as deterrence ‘may serve civil as well as criminal goals.’ ” Hudson, 118 S.Ct. at 496 (citation omitted). The fines provision was also intended to serve a remedial purpose, namely, lessening the attractiveness of U.S. jobs to illegal immigrants. Accordingly, this factor is mixed.
Behavior Which Has Been Criminalized
18 U.S.C. § 1546 criminalizes the precise conduct penalized in the instant case. This factor is not determinative, however, particularly given the amount of time that elapsed between the criminalizing of this conduct and the establishment of a civil penalty. Section 1324c was passed in 1990, while the comparative criminal sanction was originally enacted in 1924. See Act, ch. 190, § 21, 62 Stat. 862 (1924). As the Supreme Court noted in United States v. Ward, “the placement of criminal penalties in one statute and the placement of civil penalties in another statute enacted 70 years later tends to dilute the force of the fifth ... criterion.” Ward, 448 U.S. at 250, 100 S.Ct. 2636 (finding that a monetary fine for an environmental offense was civil in nature despite the fact that the same conduct was subject to a criminal offense).
Non-Criminal Purposes
Section 1324c furthers several non-punitive purposes, including (1) reimbursing the government for enforcement expenditures under the Immigration and Naturalization Act, 8 U.S.C. § 1330(3)(A), (2) ensuring that persons committing fraud -do not profit from their acts, see United *1174States v. Ursery, 518 U.S. 267, 291, 116 S.Ct. 2135, 135 L.Ed.2d 549 (1996), and (3) immigration regulation. Cf. Cole v. U.S. Dep’t of Agric., 133 F.3d 803, 806 (11th Cir.1998) (distinguishing between regulatory and criminal goals). See also Immigration & Naturalization Service v. National Center for Immigrants’ Rights, 502 U.S. 183, 187-94, 112 S.Ct. 551, 116 L.Ed.2d 546 (1991) (noting that IRCA expresses Congress’ determination that employment of undocumented aliens was an important part of U.S. immigration law).
Excessiveness of Penalty
The INS based its recommendation of a $96,000 fine in this case on the fact that the investigation of Noriega-Perez and his alleged coconspirators involved many hours of investigation by numerous agents, at a cost of approximately $48,000.
The imposition of a $96,000 civil fine for more than 300 fraudulent violations is not excessive in light of the Act’s remedial purposes. See United States v. Lippert, 148 F.3d 974, 977 (8th Cir.1998) (fine not excessive where it was difficult to prove the government’s damages and the government incurred investigative and enforcement costs).
In sum, evaluation under the seven Hudson factors is mixed. On balance the factors here do not demonstrate by the clearest proof that section 1324c’s monetary sanction is so punitive that it is criminal in nature.4 Accordingly, section 1324c imposes a civil, not criminal, sanction.
B. Article III
Noriega-Perez asserts that the imposition of the fine by an ALJ pursuant to section 1324c violated the separation of powers. According to Noriega-Perez, such a fine could only have been imposed by an Article III judge. For the reasons set forth below, we disagree.
1. Background
“On its most. fundamental plane, the separation of powers doctrine protects the whole constitutional structure by requiring that each branch retain its essential powers and independence.” Pacemaker Diagnostic Clinic of America v. Instromedix, 725 F.2d 537, 544 (9th Cir.) (en banc), cert. denied, 469 U.S. 824, 105 S.Ct. 100, 83 L.Ed.2d 45 (1984). Article III, section 1, of the U.S. Constitution provides in pertinent part:
The judicial Power of the United States shall be vested in one supreme Court and in such inferior Court as the Congress may from time to time ordain and establish. The Judges of the supreme and inferior Courts, shall hold their Offices during good Behavior, and shall, at stated Times, receive for their Services, a Compensation, which shall not be diminished during their Continuance in office.
Because ALJs lack the characteristics of Article III judges, including life tenure, they are generally prohibited from exercising “judicial power.” See Simpson v. Office of Thrift Supervision, 29 F.3d 1418, 1422 (9th Cir.1994), cert. denied, 513 U.S. 1148, 115 S.Ct. 1096, 130 L.Ed.2d 1064 (1995).
The resolution of disputes by non-Article III judges, such as ALJs, implicates serious concerns regarding our constitutionally established system of checks and balances. “A judiciary free from control by the Executive and the Legislature is essential if there is a right to have claims decided by judges who are free from potential domination by other branches of government.” United States v. Will, 449 U.S. 200, 218, 101 S.Ct. 471, 66 L.Ed.2d 392 (1980).
Importantly, however, “neither [the Supreme Court] nor Congress has read the *1175Constitution as requiring every federal question arising under the federal law ... to be tried in an Art. Ill court.” Thomas v. Union Carbide Agric. Prods., Co., 473 U.S. 568, 582, 105 S.Ct. 3325, 87 L.Ed.2d 409 (1985) (quoting Palmore v. United States, 411 U.S. 389, 407, 93 S.Ct. 1670, 36 L.Ed.2d 342 (1973)). Congress began authorizing adjudication by agencies in 1789, when it empowered the Comptroller within the Treasury Department to resolve all disputes concerning claims against the Treasury. Since then, a line of Supreme Court cases has developed excepting certain actions from initial adjudication by an Article III body. The Supreme Court first validated the adjudication of a federal question by a non-Article III forum in 1828. See American Ins. Co. v. Canter, 26 U.S. 511, 1 Pet. 511, 7 L.Ed. 242 (1828) (upholding territorial court’s authority to hear admiralty cases). Thereafter, in 1855, the Supreme Court articulated another exception to the general requirements of Article III adjudication, holding that a non-Article III forum could resolve disputes involving “public rights.” See Murray’s Lessee v. Hoboken Land & Improvement Co., 59 U.S. 272, 18 How. 272, 15 L.Ed. 372 (1855).
In Northern Pipeline v. Marathon Pipe Line Co., the Supreme Court articulated three narrow classes of cases in which Article III concerns do not mandate resolution of- federal disputes by Article III judges: (1) public rights; (2) territorial courts; and (3) military courts. 458 U.S. 50, 69, 102 S.Ct. 2858, 73 L.Ed.2d 598 (1982) (Brennan, J; plurality). Although the boundaries of, as well as the importance of the distinction between, public and private rights for Article III purposes have shifted over the years, compare Northern Pipeline, 458 U.S. at 69, 102 S.Ct. 2858 with Union Carbide, 473 U.S. at 589, 105 S.Ct. 3325, and Granfinanciera v. Nordberg, 492 U.S. 33, 54-56, 109 S.Ct. 2782, 106 L.Ed.2d 26 (1989), the field of immigration-with which we are concerned here-has remained solidly within- “public rights” and the statutory delegation to agencies of the power to adjudicate immigration issues has been consistently upheld by the courts. See, e.g., Crowell v. Benson, 285 U.S. 22, 51, 52 S.Ct. 285, 76 L.Ed. 598 (1932); Zakonaite v. Wolf, 226 U.S. 272, 33 S.Ct. 31, 57 L.Ed. 218 (1912); Turner v. Williams, 194 U.S. 279, 24 S.Ct. 719, 48 L.Ed. 979 (1904); Morel v. Immigration & Naturalization Serv., 144 F.3d 248, 251-52 (3d Cir.1998); Austin v. Shalala, 994 F.2d 1170, 1177-78 (5th Cir.1993).
2. Schor Inquiry
Since Northern Pipeline, the Supreme Court has moved away from a formalistic approach to separation of powers questions. See Commodity Futures Trading Comm’n v. Schor, 478 U.S. 833, 106 S.Ct. 3245, 92 L.Ed.2d 675 (1986). The Court has recognized that “our precedents in this area do not admit of easy synthesis.... Rather, the constitutionality of a given congressional delegation of adjudicative functions to a non-Article III body must be assessed by reference to the purpose underlying the requirements of Article III.” Id. at 846-47, 106 S.Ct. 3245. Schor suggests the balancing of four non-determinative factors in determining the constitutionality of congressional delegation of matters to a non-Article III forum:
Among the factors upon which we have focused are the extent to which the “essential attributes of judicial power” are reserved to Article III courts, and conversely, the extent to which the non-Article III forum exercises the range of jurisdiction and powers normally vested only in Article III courts, the origins and importance of the right to be adjudicated, and the concerns that drove Congress to depart from requirements of Article III.
Id. at 851, 106 S.Ct. 3245.
Although the Supreme Court has approved of the imposition of civil fines by administrative agencies for violations of U.S. immigration law, see Austin v. Shalala, 994 F.2d 1170, 1177-78 (5th Cir.1993) (citing Lloyd Sabaudo Societa v. Elting, 287 U.S. 329, 335, 53 S.Ct. 167, 77 L.Ed. *1176341 (1932)), the determination that the sanction imposed in this case is civil does not end our inquiry. “[P]ractical attention to substance rather than doctrinaire reliance on formal categories should inform application of Article III.” Thomas, 473 U.S. at 586, 105 S.Ct. 3325. In determining the constitutionality of congressional delegation of adjudicatory power over section 1324c fines to a non-Article III forum, the four factors articulated in Schor must be considered.
Extent to Which the Essential Attributes of Judicial Power Are Reserved to Ariicle III Courts
In order to retain the essential attributes of judicial power, “there must be both the appearance and the reality of control by Article III judges over the interpretation, declaration, and application of federal law.” Pacemaker Diagnostic Clinic, 725 F.2d at 544. Under section 1324c, hearings conducted pursuant to section 1324c are governed by the Administrative Procedure Act (APA), 5 U.S.C. § 554. See 8 U.S.C. § 1324c(d)(2)(B). See also 28 C.F.R. § 86 et seq. Although aspects of section 1324c are troublesome, Article III courts retain their essential attributes under section 1324c’s adjudicatory scheme.
Important to this determination is the level of judicial review retained over ALJ decisions. See Schor, 478 U.S. at 853, 106 S.Ct. 3245 (noting the importance of de novo appellate review of questions of law).5 An appropriate level of judicial review ensures that Article III courts retain “the appearance and reality of control ... over the interpretation, declaration, and application of federal law.” Pacemaker Diagnostic Clinic, 725 F.2d at 544. Section 1324c provides for appellate review in that “[a] person or entity adversely affected by a final order under this section may ... file a petition in the Court of Appeals for the appropriate circuit for review of the order”. 8 U.S.C. § 1324e(d)(5). This section imposes a de novo standard of review on conclusions of law. See Villegas-Valenzuela v. Immigration & Naturalization Service, 103 F.3d 805, 808 (9th Cir.1996) (“We review questions of statutory interpretation de novo.”). See also Maka v. Immigration & Naturalization Service, 904 F.2d 1351, 1355 (9th Cir.1990) (“We review de novo an agency’s conclusions of law.... Within the de novo framework we give a certain amount of deference to an agency’s reasonable construction of a statute it is charged with administering.’ ”) (citation omitted), amended 904 F.2d 1351 (9th Cir.1990).
Pursuant to the APA, factual findings may only be overturned on appeal if they are “unsupported by substantial evidence.” Mester Mfg. Co. v. Immigration & Naturalization Service, 879 F.2d 561, 565 (9th Cir.1989).6 This standard is less deferential than the “clearly erroneous” standard viewed with disfavor in Northern Pipeline. See Northern Pipeline, 458 U.S. at 85, 102 S.Ct. 2858. It is similar to the “supported by the evidence” standard imposed in the adjudicatory scheme found constitutional in Crowell v. Benson, 285 U.S. 22, 46-48, 52 S.Ct. 285, 76 L.Ed. 598 (1932). See also Northern Pipeline, 458 U.S. at 85, 102 S.Ct. 2858.
Pursuant to section 1324c, an ALJ may impose a fine. Although this may seem to be within the purview of an Article III court, this concern is mitigated because ALJs do not have the authority to enforce the fine. Section 1324c explicitly requires *1177that the government seek enforcement of the final order in “any appropriate district court” if a party fails to comply with the ALJ’s order. See 8 U.S.C. § 1324c(d)(6). See also 28 C.F.R. § 68.53. Accordingly, under section 1324c, Article III courts retain the essential attributes of judicial power.
Limited Jurisdiction Assigned to Administrative Agency
Section 1324c provides ALJs with limited jurisdiction to impose a sanction. They may only impose a civil fine. Although Noriega-Perez argues that section 1324c entrusts non-Article III forums with the “essential attributes” of Article III courts because the penalty imposed by section 1324c is criminal in nature, Hudson compels the conclusion that section 1324c imposes a civil, not criminal, sanction.
Furthermore, the grant of jurisdiction to administrative tribunals under section 1324c is limited in scope. The ALJ is given jurisdiction over a “particularized area of law.” Schor, 478 U.S. at 852, 106 S.Ct. 3245 (citation omitted). Section 1324c applies only to fraud committed “for the purpose of satisfying requirements of [the Immigration and Nationality Act].” 8 U.S.C. § 1324c(a)(2). The bankruptcy scheme invalidated in Northern Pipeline, on the other hand, involved a broad grant of jurisdiction extending to “all civil proceedings ... arising in or related to cases under title 11.” Northern Pipeline, 458 U.S. at 85, 102 S.Ct. 2858 (quoting 28 U.S.C. § 1471(b)). Therefore, the jurisdiction granted to ALJs under section 1324c is limited in scope.
Nature of the Right to be Adjudicated
Section 1324c involves the public right to regulate immigration. See Crowell, 285 U.S. at 51, 52 S.Ct. 285 (1932). As discussed above, public rights is one of the areas best established as suitable for adjudication by an administrative agency. See Northern Pipeline, 458 U.S. at 67-68, 102 S.Ct. 2858. Additionally, because section 1324c imposes a civil sanction, it does not implicate the important rights afforded to criminal defendants under the Constitution.
Controlling the unlawful employment of undocumented aliens has been recognized as an important aspect of U.S. immigration law. See Immigration & Naturalization Serv. v. National Center for Immigrants’ Rights, Inc., 502 U.S. 183, 187, 112 S.Ct. 551, 116 L.Ed.2d 546 (1991). In fact, the Supreme Court has long recognized that the power to exclude alien laborers is “necessarily intertwined with the power to punish any who assist in their introduction.” Lees v. United States, 150 U.S. 476, 478-79, 14 S.Ct. 163, 37 L.Ed. 1150 (1893).7 Furthermore, as the Fifth Circuit has noted, the Supreme Court “has approved the use of administrative agencies in adjudicating violations of the customs and immigration laws and assessing penalties therefor.” Austin v. Shalala, 994 F.2d 1170, 1177-78 (5th Cir.1993) (citing Lloyd Sabaudo So-cieta Anonima Per Azioni v. Elting, 287 U.S. 329, 335, 53 S.Ct. 167, 77 L.Ed. 341 (1932)). Accordingly, section 1324c properly implicates the adjudication of the public right to regulate immigration.
Congressional Concerns Behind Section 1321c
The fourth and final factor, congressional concerns behind passage of section 1324c, demonstrates that Congress acted with a proper purpose. Noriega-Perez relies on statements made by Senator Alan Simpson three years after the enactment of section 1324c. See 139 Cong. Rec. *1178S15958, S15964 (daily ed. Nov. 17, 1993). He maintains that these statements suggest that Congress possessed an improper purpose when it enacted section 1324c because it was concerned with the inefficient prosecution of these cases pursuant to section 1324c’s criminal counterpart. We do not agree that the statements establish an improper purpose.
Efficiency is a valid concern that may drive “Congress to depart from the requirements of Article III.” Schor, 478 U.S. at 851, 106 S.Ct. 3245. In Schor, the Supreme Court upheld a statute creating a non-Article III forum that was intended “to create an inexpensive and expeditious alternative forum.” Id. at 855, 106 S.Ct. 3245. Other federal courts have recognized that efficiency and reduced expense are proper purposes for committing matters for adjudication by administrative tribunals. See United States v. Seals, 130 F.3d 451, 460 (D.C.Cir.1997), cert. denied, — U.S. -, 118 S.Ct. 2323, 141 L.Ed.2d 697 (1998).8
In fact, efficiency is one of the primary reasons Congress grants adjudicatory functions to non-Article III judges. See Richard H. Fallon, Jr., Of Legislative Courts, Administrative Agencies, and Article III, 101 Harv. L.Rev. 915, 935-36 (1988). Few, if any, non-Article III courts would survive judicial scrutiny if efficiency became an impermissible reason for their establishment.
Accordingly, examination of all four Schor factors demonstrates that section 1324c does not disturb “the whole constitutional structure” by impermissibly delegating Article III judicial power to a non-Article III court.
S. Free of Potential Domination By Other Branches
The four Schor factors, however, address only one of the purposes of Article III, to protect “the role of the independent judiciary within the constitutional scheme,” Schor, 478 U.S. at 850, 106 S.Ct. 3245. We must also consider whether the delegation at issue here endangers litigants’ “right to have claims decided before judges who are free of potential domination by other branches of government.” Id. Although the congressional scheme embodied in section 1324c poses little danger to the role of the independent judiciary, the possible domination by the executive branch necessitates an additional inquiry. This issue is a of particular concern where, as here, the parties are compelled to proceed before a non-Article III tribunal.
The Supreme Court has pointed to a party’s consent to an initial adjudication before a non-Article III tribunal as a significant factor in determining that Article III permits adjudication. See Schor, 478 U.S. at 848-50, 855, 106 S.Ct. 3245 (separation of powers concerns are diminished where the decision to invoke the non-Article III forum is left entirely to the parties and the power of the federal judiciary to take jurisdiction of these matters is unaffected). Nevertheless, we conclude that, because of the due process protections afforded by the scheme at issue here and the historic treatment of immigration issues as matters subject to initial resolution in an administrative forum, Congress’ delegation of adjudicatory power over section 1324c disputes does not violate Article III. See Paul Verkuil, Separation of Powers, The Role of Law, and the Idea of Independence, 30 Wm. & Mary L.Rev. 301, 316-17 (1988).
Conclusion
Because we reject both of the constitutional challenges to the fine imposed in this case and because section 1324c involves a civil fine constitutionally imposed in a non-Article III forum, we affirm.
. Noriega-Perez raises five other issues on appeal. First, he claims that the fine of $96,-000 imposed upon him by the ALJ constitutes an excessive fine under the Eighth Amendment. This challenge fails because a fine of $96,000 for possessing and counterfeiting over 300 fraudulent documents is hardly "grossly disproportional” to the gravity of Noriega-Perez's offense, particularly considering the INS’ assertion that its cost of investigation was approximately $48,000. See United States v. Bajakajian, 524 U.S. 321, 118 S.Ct. 2028, 2037-38, 141 L.Ed.2d 314 (1998). Second, Noriega-Perez asserts that it was improper for the ALJ to grant summary judgment because of his assertion of his Fifth Amendment right against self-incrimination. However, petitioner had no valid claim of Fifth Amendment privilege to assert, for he had already pleaded guilty to criminal charges based on his actions and thus could not be criminally prosecuted again. Even assuming he did have a valid Fifth Amendment privilege, he failed to assert the basis of his fear of incrimination with the requisite specificity. See Brunswick Corp. v. Doff, 638 F.2d 108, 110 (9th Cir.1981). Third, Noriega-Perez complains that the ALJ improperly denied his motion for a continuance of the hearing. The ALJ had previously granted petitioner three extensions of time and did not abuse his discretion in denying the fourth such request. Fourth, petitioner claims that the ALJ erred in failing to order the INS to respond to a discovery request. Noriega-Perez has failed to show, however, that the documents he requested were relevant and could have affected the outcome of the summary judgment motion. Finally, petitioner contends that he was unconstitutionally denied a jury trial. It follows from our holding that an administrative hearing complies with the Constitution that a jury trial was not required.
. Neither party discussed this aspect of the double jeopardy issue, perhaps because the majority did not address it in Hudson. Although Justice Stevens discussed this issue in his concurrence, the majority chose not to address it because it had not been presented in the petition for certiorari. Hudson, 118 S.Ct. at 494 n. 5. Nevertheless this parL of the double jeopardy inquiry remains a necessary part of double jeopardy analysis.
. The Hudson/Kennedy guideposts are pertinent to this inquiry because a finding that the sanction imposed by section 1324c is criminal would implicate the safeguards that attend a criminal prosecution. See Austin v. United States, 509 U.S. 602, 610 n. 6, 113 S.Ct. 2801, 125 L.Ed.2d 488 (1993). Furthermore, the Supreme Court has previously utilized Kennedy v. Mendoza-Martinez to determine whether congressional action constituted punishment in the separation of powers context. See Nixon v. Administrator of Gen. Servs., 433 U.S. 425. 477. 97 S.Ct. 2777. 53 L.Ed.2d 867 (1977) (finding that a congressional Act did not violate the Bill of Attainder Clause because it did not impose a punishment). Significantly, the Supreme Court noted that "the Bill of Attainder Clause was an important ingredient of the doctrine of separation of powers.” Id. at 470, 97 S.Ct. 2777. See also United States v. Brown, 381 U.S. 437, 442-43, 85 S.Ct. 1707, 14 L.Ed.2d 484 (1965) (noting that Article III and the Bill of Attainder Clause serve the separation of powers doctrine).
. Although the dissent argues that the majority gives the Hudson/Kennedy guideposts too much deference, this application is consistent with many other appellate court opinions that have given the factors great weight. See, e.g., Louis v. Commissioner of Internal Revenue, 170 F.3d 1232 (9th Cir.1999); Herbert v. Billy, 160 F.3d 1131 (6th Cir.1998); Securities and Exchange Comm'n v. Palmisano, 135 F.3d 860 (2d Cir.1998).
. Although informative, this factor is not necessarily determinative. See Thomas, 473 U.S. at 583, 105 S.Ct. 3325 (“Many matters that involve the application of legal standards to facts and affect private interests are routinely decided by agency action with limited or no review by Article III courts.”). See also Morel, 144 F.3d at 251-52 (“[R]elevant Supreme Court authority does not mandate judicial review by an Article III court of questions of law underlying legislatively-created public rights such as immigration.”) (citation omitted).
. "[Substantial evidence] means such relevant evidence, as a reasonable mind might accept as adequate to support a conclusion.” Maka, 904 F.2d at 1355.
. Federal immigration law has historically addressed immigrant labor concerns by providing for non-criminal sanctions against individuals and regulated companies attempting to evade regulation. See Grant Brothers Constr. Co. v. United States, 232 U.S. 647, 658, 34 S.Ct. 452, 58 L.Ed. 776 (1914) (upholding the award of a civil fine against a defendant who "solicited the migration and importation into the United States ... of a designated alien laborer”); Millon, 219 F. at 187; United States v. Banister, 70 F. 44, 44 (C.C.D.Vt.1895).
. Cf. Mistretta v. United States, 488 U.S. 361, 363-64, 109 S.Ct. 647, 102 L.Ed.2d 714 (1989).