OPINION
KAREN NELSON MOORE, Circuit Judge.
Defendant Tyrone McMurray was convicted at a bench trial of violating the federal felon-in-possession-of-arfirearm statute. He now appeals his 180-month sentence of imprisonment — -the statutorily mandated minimum as a result of the district court’s determination that McMurray qualifies to be sentenced under the-Armed [370]*370Career Criminal Act (“ACCA”). McMurray argues that (1) the predicate felony convictions for the ACCA must be included in the indictment and proven beyond a reasonable doubt, and (2) his 1993 felony conviction for aggravated assault is not a “violent felony” under the ACCA. Because Tennessee’s aggravated-assault statute is not categorically a “violent felony” and because the available Shepard documents do not establish the nature of McMurray’s conviction, we VACATE the judgment of the district court and REMAND for resentencing consistent with this opinion.
I. BACKGROUND & PROCEDURE
On December 20, 2006, McMurray was indicted on one charge of violating the federal felon-in-possession-of-a-firearm statute, 18 U.S.C. , § 922(g)(1). After McMurray waived his right to a jury trial, the district court conducted a bench trial and found McMurray guilty. Prior to sentencing, U.S. Probation Services prepared a Presentence Investigation Report (“PSR”), which concluded that McMurray had been convicted of three prior violent felonies and therefore qualified for a sentence enhancement under the ACCA, 18 U.S.C. § 924(e). Specifically, the PSR concluded that McMurray qualified as an armed career criminal based on the following Tennessee convictions: (1) aggravated assault in 1986, (2) armed robbery in 1987, and (3) aggravated assault in 1993.
McMurray challenged the application of the ACCA for the two reasons that he now asserts on appeal. At a sentencing hearing held on June 17, 2009, however, the district court rejected McMurray’s arguments that he did not qualify for an enhancement under the ACCA. On June 19, 2009, the district court entered its judgment, sentencing McMurray to 180 months of imprisonment, the statutorily mandated minimum under the ACCA.
II. ANALYSIS
A. Armed Career Criminal Act
McMurray faced a maximum prison term of ten years for violating 18 U.S.C. § 922(g), the felon-in-possession-of-a-firearm statute. 18 U.S.C. § 924(a)(2). Pursuant to the ACCA, however, a defendant convicted under § 922(g) who “has three previous convictions ... for a violent felony or a serious drug offense, or both,” must be sentenced to “not less than 15 years” of imprisonment. Id. § 924(e)(1). A “violent felony” is “any crime punishable by imprisonment for a term exceeding one year” that “(i) has as an element the use, attempted use, or threatened use of physical force against the person of another; or (ii) is burglary, arson, or extortion, involves use of explosives, or otherwise involves conduct that presents a serious potential risk of physical injury to another.” Id. § 924(e)(2)(B).
B. Constitutional Challenges
McMurray first argues that violating the ACCA is “a separate criminal offense,” and, therefore, pursuant to the Due Process Clause, the predicate felony convictions must be included in the indictment and proven beyond a reasonable doubt. Appellant Br. at 11. He argues that his “conviction for being an armed career criminal felon should be vacated.” Id.
We review de novo challenges to the sufficiency of an indictment. United States v. Gatewood, 173 F.3d 983, 986 (6th Cir.1999). We have rejected the argument that the ACCA sentencing provision is a separate offense and that the government must plead in the indictment and prove beyond a reasonable doubt the predicate felonies. United States v. Wolak, 923 F.2d 1193, 1199 (6th Cir.), cert. denied, 501 U.S. 1217, 111 S.Ct. 2824, 115 L.Ed.2d 995 [371]*371(1991); United States v. Brewer, 858 F.2d 1319, 1322 (6th Cir.1988) (on reh’g) (analyzing antecedent statute to the ACCA), cert. denied, 488 U.S. 946, 109 S.Ct. 375, 102 L.Ed.2d 364 (1988), 489 U.S. 1021, 109 S.Ct. 1142, 103 L.Ed.2d 202 (1989). That the ACCA is a sentence enhancement rather than a separate offense is well established. See, e.g., Custis v. United States, 511 U.S. 485, 490, 114 S.Ct. 1732, 128 L.Ed.2d 517 (1994) (“The ACCA provides an enhanced sentence----”); Taylor v. United States, 495 U.S. 575, 577, 110 S.Ct. 2143, 109 L.Ed.2d 607 (1990) (“[The ACCA] provides a sentence enhancement....”). Thus, McMurray’s due-process challenge to the ACCA may be more appropriately construed as a constitutional challenge to his sentence — which we also review de novo. United States v. Martin, 526 F.3d 926, 941 (6th Cir.), cert. denied, - U.S. -, 129 S.Ct. 305, 172 L.Ed.2d 223 (2008). We have observed that due process does not require the government to provide prior notice of its intention to seek a sentence enhancement under the ACCA. United States v. Mauldin, 109 F.3d 1159, 1163 (6th Cir.1997); United States v. Miller, 371 Fed.Appx. 646, 649-50 (6th Cir.2010) (unpublished decision); accord United States v. Mack, 229 F.3d 226, 231 (3d Cir.2000) (collecting cases holding the same), cert. denied, 532 U.S. 1045, 121 S.Ct. 2015, 149 L.Ed.2d 1016 (2001).
The Supreme Court, in Almendarez-Torres v. United States, 523 U.S. 224, 226-27, 118 S.Ct. 1219, 140 L.Ed.2d 350 (1998), held that when a statute constitutes a penalty provision, rather than a separate crime, the government need not include the provision in the indictment. “[T]he Supreme Court has uniformly excepted ‘the fact of a prior conviction’ from its general rale that sentence-enhancing facts must be found by a jury and proved beyond a reasonable doubt.” Martin, 526 F.3d at 941 (citing United States v. Booker, 543 U.S. 220, 244, 125 S.Ct. 738, 160 L.Ed.2d 621 (2005); Apprendi v. New Jersey, 530 U.S. 466, 490, 120 S.Ct. 2348, 147 L.Ed.2d 435 (2000)). McMurray challenges the continuing validity of Almendarez-Torres, but, in Martin, 526 F.3d at 941-42, we concluded that this court remains bound by Almendarez-Torres despite statements in Shepard v. United States, 544 U.S. 13, 125 S.Ct. 1254, 161 L.Ed.2d 205 (2005), suggesting that it is no longer good law. Counsel for McMurray acknowledged at oral argument that we remain bound by Martin. See Salmi v. Sec’y of Health & Human Servs., 774 F.2d 685, 689 (6th Cir.1985) (“A panel of this Court cannot overrule the decision of another panel.”).
We therefore reject McMurray’s constitutional challenges to the enhancement of his sentence under the ACCA.
C. Whether Tennessee Crime of Aggravated Assault Is a “Violent Felony” Under the ACCA
McMurray also challenges the district court’s determination that his 1993 Tennessee conviction for aggravated assault, Tenn.Code Ann. § 39-13-102 (1991), qualifies as a “violent felony” under the ACCA because the Tennessee statute encompasses reckless conduct. We review de novo the district court’s determination that a prior conviction qualifies as a “violent felony” under the ACCA. United States v. Gross, 624 F.3d 309, 322 (6th Cir.2010). The two-step analysis for determining whether a prior conviction qualifies as a “violent felony” is well established 1:
[372]*372In determining the nature of a prior conviction, we are to apply a “categorical” approach, looking to the statutory definition of the offense and not the particular facts underlying the conviction. Taylor v. United States, 495 U.S. 575, 600, 110 S.Ct. 2143, 109 L.Ed.2d 607 (1990). If it is possible to violate the statute in a way that would constitute a [“violent felony”] and in a way that would not, the court may consider the indictment, guilty plea, or similar documents to determine whether they necessarily establish the nature of the prior conviction. Shepard v. United States, 544 U.S. 13, 26, 125 S.Ct. 1254, 161 L.Ed.2d 205 (2005).
United States v. Gibbs, 626 F.3d 344, 352 (6th Cir.2010).
1. Taylor Categorical Analysis of Tennessee’s Aggravated-Assault Statute
McMurray pleaded guilty to aggravated assault on April 29, 1993. At that time, the Tennessee statute for aggravated assault was as follows:
(a) A person commits aggravated assault who:
(1) Commits an assault as defined in § 39-13-101 and:
(A) Causes serious bodily injury to another; or
(B) Uses or displays a deadly weapon; or
(2) Being the parent or custodian of a child or the custodian of an adult, intentionally or knowingly fails or refuses to protect such child or adult from an aggravated assault described in subsection (a); or
(3) After having been enjoined or restrained by an order, diversion or probation agreement of a court of competent jurisdiction from in any way causing or attempting to cause bodily injury or in any way committing or attempting to commit an assault against an individual or individuals, attempts to cause or causes bodily injury or commits or attempts to commit an assault against such individual or individuals.
(b) Aggravated assault is a Class C felony....
Tenn.Code Ann. § 39-13-102 (1991).2 Tennessee’s assault statute at that time, Tenn.Code Ann. § 39-13-101 (1991), provided in relevant part:
(a) A person commits assault who:
(1) Intentionally, knowingly or recklessly causes bodily injury to another;
(2) Intentionally or knowingly causes another to reasonably fear imminent bodily injury; or
(3) Intentionally or knowingly causes physical contact with another and a reasonable person would regard the contact as extremely offensive or provocative.
[373]*373Tennessee’s aggravated-assault statute, both the version effective at the time of McMurray’s conviction and the current version, encompasses a wide range of conduct, such as hitting and choking the victim while threatening her with a gun, State v. Hammonds, 30 S.W.3d 294, 297 (Tenn.2000), and reckless driving resulting in a collision that causes serious bodily injury to another, State v. Gillon, 15 S.W.3d 492, 496-97 (Tenn.Crim.App.1997).
McMurray argues that because the aggravated-assault statute encompasses reckless conduct, his conviction does not qualify as a “violent felony.”. First, we note that this court concluded, in the analogous context of a “crime of violence” under 18 U.S.C. § 16,3 that reckless aggravated assault under the use-or-display-of-a-deadly-weapon prong nevertheless requires intentional conduct. United States v. Mendoza-Mendoza, 239 Fed.Appx. 216, 219-21 (6th Cir.2007) (unpublished decision), cert. denied, 552 U.S. 1121, 128 S.Ct. 927, 169 L.Ed.2d 767 (2008). We assume, without deciding, that the analysis of Mendoza-Mendoza extends to the ACCA, and therefore consider, for purposes of this analysis, reckless aggravated assault under the serious-bodily-injury prong, § 39-13-102(a)(l)(A) (1991). Because aggravated assault is not an enumerated crime,4 we analyze whether recklessly causing serious bodily injury to another meets either the “use of' physical force” clause, 18 U.S.C. § 924(e)(2)(B)®, or the “otherwise” clause, id. § 924(e)(2)(B)(ii), of the ACCA’s definition of a “violent felony.” See United States v. Sanders, 470 F.3d 616, 621 n. 4 (6th Cir.2006) (emphasizing that a crime can be a “violent felony” under either clause).
a. “Use of Physical Force” Clause
We first consider whether recklessly causing serious bodily injury to another, § 39-13-102(a)(l)(A) (1991), “has as an element the use, attempted use, or threatened use of physical force against the person of another.” 18 U.S.C. § 924(e)(2)(B)(i). We find the decisions in Leocal v. Ashcroft, 543 U.S. 1, 125 S.Ct. 377, 160 L.Ed.2d 271 (2004), and United States v. Portela, 469 F.3d 496 (6th Cir.2006), instructive.
In Leocal, the Supreme Court considered whether a Florida conviction for driving under the influence (“DUI”) and causing serious bodily injury qualifies as a “crime of violence” under 18 U.S.C. § 16. 543 U.S. at 3, 125 S.Ct. 377. In its analysis of the statute’s “use of force” clause, § 16(a), which is in relevant part identical to the “use of force” clause of the ACCA, [374]*374§ 924(e)(2)(B)(i), the Court relied on its decision in Bailey v. United States, 516 U.S. 137, 116 S.Ct. 501, 133 L.Ed.2d 472 (1995), to conclude that “ ‘use’ requires active employment” and “most naturally suggests a higher degree of intent than negligent or merely accidental conduct.” Leocal, 543 U.S. at 9, 125 S.Ct. 377. The Court reasoned that “[w]hile one may, in theory, actively employ something in an accidental manner, it is much less natural to say that a person actively employs physical force against another person by accident.” Id. Because Florida’s DUI statute did not require proof of a particular mental state, the Court concluded that the defen-dant’s DUI conviction was not a “crime of violence” under the “use of force” prong of § 16. Id. at 7, 10, 125 S.Ct. 377. The Court, however, expressly indicated that it was not deciding whether a statute that encompasses reckless conduct qualifies as a “crime of violence.” Id. at 13, 125 S.Ct. 377.
In Pórtela, we answered the question left open by Leocal when considering whether a Tennessee conviction for vehicular assault, Tenn.Code Ann. § 39-13-106, qualified as a “crime of violence” under U.S.S.G. § 2L1.2(b)(1)(A)(ii).5 469 F.3d at 498-99. Under the Tennessee statute, “[a] person commits vehicular assault who, as the proximate result of the person’s intoxication ... recklessly causes serious bodily injury to another person by the operation of a motor vehicle.” Tenn.Code Ann. § 39-13-106(a) (emphasis added). We relied on the analysis in Oyebanji v. Gonzales, 418 F.3d 260 (3d Cir.2005) (Alito, J.), and Bejarano-Urrutia v. Gonzales, 413 F.3d 444 (4th Cir.2005), which applied Leo-cal’s reasoning to convictions involving reckless conduct, and we concluded that the defendant’s conviction for vehicular assault was not a “crime of violence” under § 2L1.2(b)(l)(A)(ii). Portela, 469 F.3d at 499. In the context of § 16, the extension of Leocal’s reasoning to conclude that reckless conduct does not constitute a “crime of violence” has found overwhelming support in our sister circuits. See United-States v. Zuniga-Soto, 527 F.3d 1110, 1124 (10th Cir.2008) (listing cases). We find the reasoning of Portela and the cases on which it relies equally persuasive in the context of the ACCA.
We further note that the Supreme Court has applied the reasoning in Leocal to the context of interpreting the ACCA’s “use of force” clause. See Johnson v. United States, — U.S. —, 130 S.Ct. 1265, 1271, 176 L.Ed.2d 1 (2010). In Johnson, the Court quoted and applied Leocal’s analysis that “ ‘[t]he ordinary meaning of [the term “crime of violence”], combined with § 16’s emphasis on the use of physical force against another person (or the risk of having to use such force in committing a crime), suggests a category of violent, active crimes.’” Johnson, 130 S.Ct. at 1271 (quoting Leocal, 543 U.S. at 11, 125 S.Ct. 377). Whereas the Court in Johnson focused on the question of the degree of physical force required to qualify as a “violent felony” — the “violent” aspect of the Leocal Court’s “violent, active crimes” characterization — we focus on the “active” aspect of the Leocal Court’s characterization.6 Thus, pursuant to Leocal [375]*375and Pórtela, we conclude that the “use of physical force” clause of the ACCA, § 924(e)(2)(B)(i), requires more than reckless conduct.
Finally, in United States v. Benton, 639 F.3d 723 (6th Cir.2011), this court recently analyzed the question whether the Tennessee crime of solicitation to commit aggravated assault is a “violent felony” under the ACCA. The court also stated that “[i]t has already been established that the crime of aggravated assault has as an element the use or threat of force, and therefore qualifies as a ‘violent felony’ for ACCA purposes.” Id. at 730 & n. 3 (citing United States v. Matthews, 278 F.3d 560, 563 (6th Cir.), cert. denied, 535 U.S. 1087, 122 S.Ct. 1991, 152 L.Ed.2d 1038 (2002)). As discussed below in Part II.C. l.b, we read the holding of Matthews to rest on the “otherwise” clause of the “violent felony” definition. Nevertheless, even if considered under the “use of physical force” clause, our decision in Matthews is equally inconsistent with the Supreme Court’s subsequent decision in Leocal as it is under the “otherwise” clause with respect to Begay v. United States, 553 U.S. 137, 128 S.Ct. 1581, 170 L.Ed.2d 490 (2008). Because the statement in Benton with respect to aggravated assault — made within its analysis of the distinct crime of solicitation to commit aggravated assault — “was not necessary to the outcome” in that case,7 it is dicta that is not binding. See [376]*376United States v. Turner, 602 F.3d 778, 786 (6th Cir.2010) (internal quotation marks omitted); accord BDT Prods., Inc. v. Lexmark Int’l, Inc., 602 F.3d 742, 750 (6th Cir.2010) (“One panel of the Sixth Circuit is not bound by dicta in a previously published panel opinion.” (alterations omitted) (internal quotation marks omitted)); PDV Midwest Refining, L.L.C. v. Armada Oil & Gas Co., 305 F.3d 498, 510 (6th Cir.2002) (“ ‘Strictly speaking an obiter dictum is a remark made or opinion expressed by a judge, in his decision upon a cause, by the way — that is, incidentally or collaterally, and not directly upon the question before the court ....”’ (quoting Black’s Law Dictionary 1100 (7th ed.1999) (alteration in original))), cert. denied, 537 U.S. 1111, 123 S.Ct. 901, 154 L.Ed.2d 784 (2003).
We conclude that the Tennessee crime of aggravated assault is not a “violent felony” under the “use of physical force” clause of the ACCA.
b. “Otherwise” Clause
We next consider whether recklessly causing serious bodily injury to another, § 39 — 13—102(a)(1)(A) (1991), “otherwise involves conduct that presents a serious potential risk of physical injury to another.” 18 U.S.C. § 924(e)(2)(B)(ii). A number of years ago, applying then-prevailing law, we concluded that a conviction for reckless aggravated assault in Tennessee is a “violent felony” under the “otherwise clause.”8 Matthews, 278 F.3d at 563 (“Reckless aggravated assault certainly ‘presents’ a serious risk of injury to its victim.”). In Begay, 553 U.S. 137, 128 S.Ct. 1581, however, the Supreme Court held that the “otherwise” clause of the “violent felony” definition, 18 U.S.C. § 924(e)(2)(B)(ii), includes only those crimes similar to the enumerated crimes — burglary, arson, extortion, and crimes involving explosives — “rather than evei"y crime that ‘presents a serious potential risk of physical injury to another.’ ” Begay, 553 U.S. at 142, 128 S.Ct. 1581. Thus, to qualify as a “violent felony” under the “otherwise” clause, the crime must “involve purposeful, violent, and aggressive conduct.”9 Id. at 144-45, 128 S.Ct. 1581 (internal quotation marks omitted); accord United States v. Baker, 559 F.3d 443, 453 (6th Cir.2009) (vacating sentence and remanding to the district court for resentencing on the issue of whether the defendant’s prior Tennessee conviction for reckless endangerment qualifies as a “crime of violence” in light of Begay); cf. Benton, 639 F.3d at 732 (concluding that the Tennessee crime of solicitation to commit aggravated assault [377]*377is a “violent felony” under the ACCA because solicitation “involves purposeful conduct, requiring as an element that the perpetrator act ‘with the intent that the criminal offense be committed’” (quoting Tenn.Code Ann. § 39-12-102)). Accordingly, after Begay, reckless aggravated assault no longer qualifies as a “violent felony” under the “otherwise” clause of § 924(e)(2)(B)®.
Because recklessly causing serious bodily injury to another does not qualify as a “violent felony” under either the “use of force” clause or the “otherwise” clause, Tennessee’s aggravated-assault statute, § 39-13-102 (1991), is not categorically a “violent felony.” Cf. United States v. McFalls, 592 F.3d 707, 716 (6th Cir.2010) (concluding that a South Carolina statute is “not categorically a crime of violence” because it “applies not only to intentional conduct, but also to reckless conduct”).
2. Shepard Documents Under the Modified-Categorical Approach
After determining that the statute does not categorically constitute a “violent felony,” we “may consider the indictment, guilty plea, or similar documents to determine whether they necessarily establish the nature of the prior conviction.” Gibbs, 626 F.3d at 352. After reviewing the record, however, we conclude that the documents supporting McMurray’s state conviction do not establish that McMurray necessarily pleaded guilty to a section of the aggravated-assault statute that constitutes a “violent felony.”
In Taylor, when setting forth the categorical approach for evaluating whether a defendant’s prior conviction qualifies as a predicate conviction for sentence enhancement, the Supreme Court also recognized that “[t]his categorical approach ... may permit the sentencing court to go beyond the mere fact of conviction in a narrow range of cases where a jury was actually required to find all the elements of [a qualifying crime].” 495 U.S. at 602, 110 S.Ct. 2143. Therefore, the Court held that a prior conviction can constitute a predicate conviction if “the charging paper and jury instructions actually required the jury to find all the elements of [a qualifying crime] in order to convict the defendant.” Id. In Shepard, the Court addressed the question of how to apply this modified-categorical approach when the defendant’s prior conviction was the result of a guilty plea. In a pleaded case, the documents must demonstrate that “the plea ... ‘necessarily’ rested on the fact identifying the [crime as a qualifying offense].” Shepard, 544 U.S. at 21, 125 S.Ct. 1254 (quoting Taylor, 495 U.S. at 602, 110 S.Ct. 2143). Thus we have held that “the question is whether the court documents establish that the defendant ‘necessarily admitted’ the elements of a predicate offense through his plea.” United States v. Medina-Almaguer, 559 F.3d 420, 423 (6th Cir.2009) (quoting Shepard, 544 U.S. at 16, 125 S.Ct. 1254).
We emphasize that our inquiry is limited to “facts [the] defendant ‘necessarily admitted’ in entering a guilty plea.” Id. at 424. In other words, we may rely only on facts “inherent in the fact of a prior conviction or admitted by the defendant.” United States v. Alston, 611 F.3d 219, 226 (4th Cir.2010). When, as hei’e, the statute of conviction is not categorically a “violent felony,” we may examine whether the underlying documents establish that the defendant pleaded guilty to a narrowed charge that would qualify as a “violent felony.” See Shepard, 544 U.S. at 25, 125 S.Ct. 1254 (plurality) (“The state statute requires no finding of [a qualifying crime], and without a charging document that narrows the charge to the [qualifying] limits, the only certainty of a [qualifying] [378]*378finding lies in jury instructions, or bench-trial findings and rulings, or (in a pleaded case) in the defendant’s own admissions or accepted findings of fact confirming the factual basis for a valid plea.”); United States v. Savage, 542 F.3d 959, 966 (2d Cir.2008) (“The Shepard Court identified two types of proof, relevant here, that might suffice to establish that a plea ‘necessarily’ rested on the elements of a predicate offense: (i) proof that the defendant admitted to predicate conduct when confirming the factual basis for a valid plea; (ii) proof that the charge was narrowed to include only predicate conduct.” (quoting Shepard, 544 U.S. at 21-22, 125 S.Ct. 1254)).
We conclude that the available documents do not demonstrate that McMurray pleaded guilty to a narrowed charge, or that McMurray admitted to facts that establish that he necessarily pleaded guilty to a section of Tennessee’s aggravated-assault statute that constitutes a “violent felony.” The record does not include the charging documents, and the documents provided — the plea petition, plea colloquy, and judgment — do not indicate expressly to which section of the aggravated-assault statute McMurray pleaded. In particular, during the plea colloquy, the parties and the trial judge referred to the charge as simply “aggravated assault.” R. 181-3 (Plea Colloquy at 1-2, 6-7). The trial judge asked McMurray, “Are you entering a best interest plea of guilty on that one charge of aggravated assault,” to which McMurray responded, “Yes, sir.” Id. at 7. The government argues that the plea petition and judgment, which state that McMurray pleaded guilty to the category of aggravated assault that is a Class C felony, R. 181-1 (Plea Pet. at 1-2); R. 185— 1 (Judgment), establish that he pleaded guilty to knowing or intentional aggravated assault. Under the current version of the Tennessee statute, this may be true. Tenn.Code Ann. § 39-13-102(e)(l) (2010) (providing that reckless aggravated assault, § 39-13-102(a)(2) (2010), is a Class D felony). McMurray, however, entered his plea and the state court entered judgment on April 29,1993, R. 181-1 (Plea Pet. at 2); R. 185-1 (Judgment), and under Tennessee’s aggravated-assault statute in effect at that time, all aggravated-assault convictions under § 39-13-102 were Class C felonies. Tenn.Code Ann. § 39-13-102(b) (1991) (“Aggravated assault is a Class C felony.”). Therefore, the fact that McMurray pleaded guilty to a Class C felony does not establish whether he pleaded guilty, to intentional, knowing, or reckless aggravated assault.
The government also asks us to consider the state’s proffer of the factual basis for the plea during the plea colloquy to conclude that McMurray acted intentionally or knowingly when he committed the aggravated assault. See R.181-3 (Plea Colloquy at 5-6) (government’s factual proffer). The plea colloquy is a document that we can consider under Shepard. 544 U.S. at 16, 125 S.Ct. 1254 (stating that the district court “is generally limited to examining the statutory definition, charging document, written plea agreement, transcript of plea colloquy, and any explicit factual finding by the trial judge to which the defendant assented”). However, McMurray entered a best-interest plea under North Carolina v. Alford, 400 U.S. 25, 91 S.Ct. 160, 27 L.Ed.2d 162 (1970), which Tennessee allows when “a defendant ... wishes to enter a plea but does not wish to acknowledge guilt.” Yant v. State, No. M2007-01936-CCA-R3-PC, 2008 WL 5330459, at *7 (Tenn.Crim.App. Dec. 22, 2008) (unpublished decision) (citing Alford, 400 U.S. 25, 91 S.Ct. 160; Hicks v. State, 983 S.W.2d 240 (Tenn.Crim.App.1998)).
We have not considered whether the prosecutor’s proffer of the factual basis for [379]*379a plea, when the defendant enters an Alford-type plea, “establishes] that the defendant ‘necessarily admitted’ the elements of [a section of the statute that constitutes a “violent felony”] through his plea.” Medina-Almaguer, 559 F.3d at 423 (quoting Shepard, 544 U.S. at 16, 125 S.Ct. 1254); see United States v. Sawyers, 223 Fed.Appx. 475, 477 n. 2 (6th Cir.2007) (unpublished decision) (noting the issue but expressing no opinion because it was abandoned on appeal), abrogated on other grounds by Begay, 553 U.S. 137, 128 S.Ct. 1581. Applying Shepard, the Fourth Circuit has held that “the prosecutor’s proffer of the factual basis for an Alford plea may not later be used by a sentencing court to identify the resulting conviction as an ACCA predicate.” Alston, 611 F.3d at 227. The District of Columbia Circuit and Second Circuit, in similar contexts, have concluded that the prosecutor’s proffer of the factual basis underlying an Alford-type plea does not demonstrate that the defendant’s plea necessarily rested on those facts if the defendant has not assented to the prosecutor’s factual proffer. United States v. Ventura, 565 F.3d 870, 878-79 (D.C.Cir.2009); Savage, 542 F.3d at 966-67.
We recently “declined to differentiate between an Alford plea and a straightforward guilty plea” when reviewing an immigration judge’s (“IJ”) decision that an alien had been convicted of “a particularly serious crime” under the Immigration and Nationality Act, § 241 (b)(3)(B)(ii), 8 U.S.C. § 1231(b)(3)(B)(ii). Ikharo v. Holder, 614 F.3d 622, 633-34 (6th Cir.2010). The alien argued that “the IJ impermissibly relied on facts contained in the indictment and plea agreement as well as during the plea hearing.” Id. at 633. In rejecting the alien’s argument, the Ikharo court relied on a Ninth Circuit case in which the court was analyzing whether a crime was a “crime of violence” under the Sentencing Guidelines and “held that the key question under the Guidelines was ‘whether a defendant has a conviction for a crime of violence, not whether the defendant has admitted to being guilty of such a crime.’ ” Id. (quoting United States v. Guerrero-Velasquez, 434 F.3d 1193, 1197 (9th Cir.2006)). The Ninth Circuit, however, has since held that the transcript of a plea hearing for a West plea — “the California equivalent of an Alford plea,” Doe v. Woodford, 508 F.3d 563, 566 n. 2 (9th Cir.2007) — does not establish the factual predicate for a sentence enhancement unless the defendant admitted to the facts. United States v. Vidal, 504 F.3d 1072, 1089 (9th Cir.2007) (en banc) (“By entering a West plea a defendant does not admit the specific details about his conduct on the counts to which he pled guilty. As a result, unless the record of the plea proceeding reflects that the defendant admitted to facts, a West plea, without more, does not establish the requisite factual predicate to support a sentence enhancement.” (alterations omitted) (citations omitted) (internal quotation marks omitted)). Although we agree with Ikharo that an Alford-type plea does not undermine the fact of a defendant’s prior conviction, we are persuaded by the reasoning of the Second, Fourth, Ninth, and District of Columbia Circuits that an Alford-type plea may impact our analysis of whether a defendant necessarily admitted the elements of a predicate offense through his plea.10 We thus de[380]*380dine to extend Ikharo to the context of the ACCA.
Declining to consider the unadmitted factual basis proffered by the state to support an Alford-type plea to establish the nature of a prior conviction is, moreover, in line with other earlier decisions of this court interpreting Shepard. We have noted that Shepard does not limit “the distinct, antecedent inquiry” of “establish[ing] the fact of the prior convictions and the resulting sentences imposed”; rather, Shepard limits what may be used “to establish the nature of the convictions or the specific offense conduct.” United States v. Jimenez, 605 F.3d 415, 421 (6th Cir.2010). We have also declined to rely on a transcript from a preliminary examination to determine the nature of a prior conviction because the defendant “did not admit [to] that conduct during the examination.” Medina-Almaguer, 559 F.3d at 423. We concluded that Shepard “requires a judicial record that identifies the facts a defendant ‘necessarily admitted’ in entering a guilty plea.” Id. at 424.
Nor does the state trial court’s finding of a factual basis for the charge establish that the defendant necessarily admitted the facts proffered by the prosecutor. In a trial context, we must determine that the decisionmaker — jury or trial judge — -was “actually required ... to find all the elements of [a qualifying crime] in order to convict the defendant.” Taylor, 495 U.S. at 602, 110 S.Ct. 2143. Thus we look to documents like charging papers, jury instructions, and a bench-trial’s formal rulings of law and findings of fact. Id.; Shepard, 544 U.S. at 20, 125 S.Ct. 1254. In contrast, in a pleaded case, the defendant — not the trial judge — is the relevant decisionmaker. When pleading guilty, the defendant is waiving his right to trial and consenting to the imposition of punishment. Alford, 400 U.S. at 37-38, 91 S.Ct. 160. We must determine what the defendant was actually required to admit when pleading guilty; thus, we look to “a transcript of plea colloquy or ... written plea agreement presented to the court, or ... a record of comparable findings of fact adopted by the defendant upon entering the plea.” Shepard, 544 U.S. at 20, 125 S.Ct. 1254 (emphasis added). The state trial court was not required to determine the truth of the state’s proffered facts relating how the crime was committed before accepting McMurray’s best-interest plea of guilty. The factual-basis requirement in Federal Rule of Criminal Procedure 11 and the equivalent state criminal-procedure rules, including Tennessee, is designed to help the trial judge evaluate the voluntariness of the defendant’s plea. See McCarthy v. United States, 394 U.S. 459, 465, 89 S.Ct. 1166, 22 L.Ed.2d 418 (1969); United States v. Tunning, 69 F.3d 107, 111 (6th Cir.1995); Yant, 2008 WL 5330459, at *8. “Thus, although a court presented with an Alford plea must make a careful inquiry into the factual basis for the plea before accepting it, the distin[381]*381guishing feature of an Alford plea is that the defendant does not confirm that factual basis.” Alston, 611 F.3d at 227 (alteration omitted) (citation omitted) (internal quotation marks omitted). In other words, the defendant is not necessarily convicted of those facts. Shepard similarly explained that the transcript of a jury trial or a police report may reveal facts underlying a defendant’s conviction but they do not establish that the. defendant was convicted of those facts. 544 U.S. at 22, 125 S.Ct. 1254. For a conviction resulting from an Alford-type guilty plea, the defendant has “necessarily” admitted to the elements of the charge but not necessarily the underlying factual basis. See Alston, 611 F.3d at, 226-27; Savage, 542 F.3d at 966-67; Tunning, 69 F.3d at 111 (stating that “a defendant who pleads guilty ... admits to acts constituting the crime,” whereas “a defendant who pleads guilty [under an Alford-type plea] either 1) affirmatively protests his innocence or 2) refuses to admit to acts constituting the crime”).
It makes no difference that everyone understood McMurray’s plea as relating to the facts alleged by the state at the plea hearing. See Savage, 542 F.3d at 967. The Court in Shepard rejected the argument that a defendant’s plea necessarily rested on particular facts because those facts are the only ones in the record underlying the charges and the defendant never explicitly disputed them. See Shepard, 544 U.S. at 19, 21-22, 125 S.Ct. 1254; Medina-Almaguer, 559 F.3d at 425 (stating, in explaining Shepard, that “[w]hat mattered was not how likely it was that Shepard had pleaded guilty to burglarizing buildings (or how unlikely it was that he had pleaded guilty to burglarizing ‘ship[s], vessel[s] or vehicle[s]’), but whether the government could produce evidence showing that Shepard ‘necessarily admitted’ to breaking into buildings when he entered his pleas”). We must consider only the facts necessarily admitted by the defendant in pleading guilty even if we are forced “to feign agnosticism about clearly knowable facts.” Shepard, 544 U.S. at 34-35, 125 S.Ct. 1254 (O’Connor, J., dissenting). Moreover, permitting the district court to rely on the state’s proffer of facts underlying the conviction, when the facts are not inherent in the crime of conviction or admitted to by the defendant, implicates the Shepard plurality’s Sixth Amendment concerns. Id. at 24-26, 125 S.Ct. 1254 (plurality); Alston, 611 F.3d at 225-26.
Finally, the fact that a plea is an Alford-type plea does not prevent the resulting conviction from ever serving as a predicate conviction for sentence enhancement. Convictions based on Alford-type pleas can be predicate convictions under the ACCA if the qualifying crime is inherent in the fact of the prior conviction — i.e., if the statute of conviction is categorically a “violent felony” or the Shepard documents demonstrate with certainty that the defendant pleaded guilty to a narrowed charge that would qualify as a “violent felony.” Cf. United States v. Vinton, 631 F.3d 476, 487 (8th Cir.2011) (concluding that a “precisely drawn charging document, which narrowed the charge to a crime that qualifies as” a “crime of violence” under § 4B1.2(a), “is one of the conclusive judicial records that can establish the basis for a defendant’s conviction under an overinclusive statute,” even if the. defendant enters an Alford plea (internal quotation marks omitted)). Additionally, any facts reflected in the Shepard documents to which the defendant did admit in the course of his Alford-type plea can be considered. See, e.g., United States v. Escalera, 401 Fed.Appx. 571, 573 (2d Cir.2010) (unpublished decision) (affirming the district court’s “determination that the offense fell within the. narrowed federal defi[382]*382nition of burglary” because the defendant, although entering an Alford plea, “ ‘confirmed’ the ‘factual basis for the plea’ ” when he responded “yes” to the district court’s question whether the factual allegations proffered by the prosecution were accurate (quoting Shepard, 544 U.S. at 26, 125 S.Ct. 1254)); United States v. Smith, 390 F.3d 661, 666 (9th Cir.2004) (relying on defense counsel’s express admission at the plea hearing that the defendant entered a home to conclude that the defendant’s conviction by nolo contendere plea encompassed the elements of generic burglary), cert denied, 546 U.S. 905, 126 S.Ct. 252, 163 L.Ed.2d 230 (2005). Nevertheless, the Court in Shepard contemplated that some convictions, as here, may not serve as predicate crimes for sentence enhancement because of “the happenstance of state court record-keeping practices and the vagaries of state prosecutors’ charging practices.” 544 U.S. at 22, 125 S.Ct. 1254 (internal quotation marks omitted).
Accordingly, we conclude that the state’s proffer of the factual basis for McMurray’s best-interest plea does not demonstrate that McMurray’s plea necessarily rested on facts identifying his aggravated-assault conviction as a “violent felony.” There is no indication in the plea transcript that McMurray admitted to the government’s proffer of the facts supporting the charge when he entered a best-interest plea. See R.181-3 (Plea Colloquy). Nor do the documents demonstrate that he pleaded to a more narrowed charge than “aggravated assault.” Because the documents do not establish that McMurray necessarily pleaded guilty to a section of the Tennessee aggravated-assault statute qualifying as a “violent felony,” McMurray’s conviction does not qualify as a predicate conviction under the ACCA.
III. CONCLUSION
For the reasons explained above, we conclude that the Tennessee aggravated-assault statute in effect at the time of McMurray’s conviction is not categorically a “violent felony” and that we cannot determine from the available Shepard documents the nature of McMurray’s conviction. Accordingly, McMurray’s 1993 aggravated-assault conviction does not qualify as a “violent felony” under the ACCA. We VACATE the judgment of the district court and REMAND for resentencing consistent with this opinion.