United States v. Singer

• Court: Court of Appeals for the Tenth Circuit
• Decided: January 23, 2026
• Docket: 23-6120
• Status: Published

Opinion

Appellate Case: 23-6120 Document: 56-1 Date Filed: 01/23/2026 Page: 1 FILED United States Court of Appeals PUBLISH Tenth Circuit

UNITED STATES COURT OF APPEALS January 23, 2026

Christopher M. Wolpert FOR THE TENTH CIRCUIT Clerk of Court _________________________________

UNITED STATES OF AMERICA,

Plaintiff - Appellee,

v. No. 23-6120

CHRISTOPHER A. SINGER, a/k/a Christopher Whitefield, a/k/a Christopher Whitfield,

Defendant - Appellant. _________________________________

Appeal from the United States District Court for the Western District of Oklahoma (D.C. No. 5:22-CR-00309-D-1) _________________________________

Laura K. Deskin, Assistant Federal Public Defender (Jeffrey M. Byers, Federal Public Defender, with her on the briefs), Office of the Federal Public Defender for the Western District of Oklahoma, Oklahoma City, Oklahoma, for Defendant-Appellant.

D.H. Dilbeck, Assistant United States Attorney (Robert J. Troester, United States Attorney, with him on the briefs), Office of the United States Attorney for the Western District of Oklahoma, Oklahoma City, Oklahoma, for Plaintiff-Appellee.

_________________________________

Before MATHESON, EID, and ROSSMAN, Circuit Judges. _________________________________

EID, Circuit Judge. _________________________________ Appellate Case: 23-6120 Document: 56-1 Date Filed: 01/23/2026 Page: 2

Christopher Singer appeals his sentence on the ground that the district court

erred in counting his state convictions based on Okla. Stat. tit. 21, § 645 toward its

sentencing calculations because § 645 is not a categorical crime of violence under

either the United States Sentencing Guidelines (the “Guidelines”) or under the Armed

Career Criminal Act (“ACCA”). This is so because, on his reading, § 645 includes

within its ambit assault and battery of an unborn victim, and, under our precedent, the

term “crime of violence” does not include any crime against unborn persons. See

United States v. Adams, 40 F.4th 1162, 1170 (10th Cir. 2022). Because we agree

with Singer that § 645 criminalizes the assault and battery of an unborn person with a

dangerous weapon, and that § 645 is thus not a categorical crime of violence, we

reverse and remand for a new sentencing consistent with this opinion.

I.

During a drive-by shooting investigation, Oklahoma City police discovered

that Christopher Singer, a felon, possessed three rounds of spent 9mm cartridge cases

and one live round of .38 ammunition. The government charged Singer with

possessing ammunition after a felony conviction, and he pleaded guilty.

At Singer’s sentencing, a United States Probation Officer submitted a

presentence investigation report (the “PSR”). The PSR noted three prior Oklahoma

state convictions: two convictions for assault and battery with a dangerous weapon,

in violation of § 645, and robbery with a firearm. Because of these convictions, the

Singer PSR concluded that Singer had at least two prior felony convictions for crimes

of violence under the Guidelines and thus calculated Singer’s base offense level as

2 Appellate Case: 23-6120 Document: 56-1 Date Filed: 01/23/2026 Page: 3

twenty-four. The Singer PSR also concluded that such convictions qualified as

violent felonies under the ACCA, and that Singer was therefore subject to a

mandatory minimum of fifteen years’ imprisonment. The Singer PSR ultimately

determined that Singer’s total offense level was thirty-one and his total criminal

history category was VI. It therefore recommended a guideline range of 188 to 235

months’ imprisonment.

Singer objected to the Singer PSR on one ground relevant here: he disputed

whether his prior Oklahoma state convictions for assault and battery with a

dangerous weapon were categorically crimes of violence under the Guidelines or

violent felonies under the ACCA. In particular, Singer argued that Oklahoma’s crime

of assault and battery with a dangerous weapon extends to victims who have not yet

been born, and therefore that it is not a categorical match for the relevant Guidelines

or ACCA definitions, which include only crimes against persons born alive.

The district court determined that it was bound by our opinion in United States

v. Taylor, 843 F.3d 1215 (10th Cir. 2016), in which we concluded that the Oklahoma

state crime of assault and battery with a dangerous weapon under § 645 is

categorically a crime of violence within the meaning of the Guidelines. The district

court also reasoned that the relevant definitions in the Guidelines and the ACCA are

identical in all relevant ways, and thus opted to apply Taylor to the ACCA context as

well. The district court therefore overruled Singer’s objection and sentenced him to

180 months’ imprisonment, in accordance with the PSR and the fifteen-year

mandatory minimum imposed by the ACCA.

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Singer filed a timely notice of appeal.

II.

We review legal determinations at sentencing de novo, including whether a

defendant’s conviction is a violent felony under the ACCA and whether it constitutes

a crime of violence under the Guidelines. See United States v. Cartwright, 678 F.3d

907, 909 (10th Cir. 2012); United States v. Wray, 776 F.3d 1182, 1184 (10th Cir.

2015).

When it comes to state law, “[t]he authority and only authority is the State,”

and “the voice adopted by the State as its own . . . should utter the last word.” Erie

R.R. Co. v. Tompkins, 304 U.S. 64, 79 (1938). Thus, when construing state law, we

refer to the decisions of a state’s courts or do our best to predict how the state’s high

court would rule. See Valley Forge Ins. v. Health Care Mgmt. Partners, Ltd., 616

F.3d 1086, 1093 (10th Cir. 2010).

III.

Singer has been convicted in Oklahoma state court of assault and battery with

a dangerous weapon in violation of § 645. Accordingly, Oklahoma law is

determinative of his appeal. In the present case, the district court found that a § 645

offense is categorically a “crime of violence” under the Guidelines, and that it should

factor into the Guidelines’ base offense level accordingly. Singer contends that such

an offense is not categorically a “crime of violence” under the Guidelines. Making

our best Erie prediction, we agree with Singer that the Oklahoma Court of Criminal

Appeals would decide that § 645 criminalizes assault with a dangerous weapon of an

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unborn person. Therefore, because § 645 proscribes conduct that is not covered by

the Guidelines’ definition of “crime of violence,” § 645 is not a “crime of violence”

for sentencing purposes.

A.

To decide whether a prior conviction “is a ‘crime of violence’ under the

Guidelines and therefore qualifies [the defendant] for an enhanced sentence,” our

precedents and those of the Supreme Court demand we apply the “categorical

approach.” United States v. O’Connor, 874 F.3d 1147, 1151 (10th Cir. 2017). Under

the categorical approach, we must look “to the elements of the statute of conviction

and not to the particular facts underlying that conviction.” Id. (cleaned up).

Therefore, our only task in this appeal is to “compare the scope of the conduct

covered by the elements of the crime” with the Guidelines’ “definition of ‘crime of

violence.’” Id.

Binding Tenth Circuit precedent controls the definition of crime of violence.

We recently held that the term “crime of violence” in § 4B1.2(a)(1) of the Guidelines

does not include any crime against unborn persons. See United States v. Adams, 40

F.4th 1162, 1170 (10th Cir. 2022) (considering a Kansas statute under the categorical

approach). As used in the Guidelines, the term “crime of violence” means “any

offense under federal or state law, punishable by imprisonment for a term exceeding

one year, that . . . has as an element the use, attempted use, or threatened use of

physical force against the person of another.” U.S. Sent’g Guidelines Manual

§ 4B1.2(a) (U.S. Sent’g Comm’n 2022). We held that, under federal law, “the person 5 Appellate Case: 23-6120 Document: 56-1 Date Filed: 01/23/2026 Page: 6

of another” means only “those born alive,” and thus excludes “victims . . . not yet

born.” Adams, 40 F.4th at 1169 (citing the Dictionary Act, 1 U.S.C. § 8(a)). We

therefore concluded that if a state crime “allows a conviction . . . when the victim is a

fetus,” there is a “mismatch” between “the elements of the state crime and the

guidelines’ definition of a crime of violence.” Id. at 1170–71 (emphasis in original).

Accordingly, as we have applied the categorical approach, such a state crime is not a

“crime of violence” under the Guidelines. See id.

One issue remains: the “scope of the conduct covered by the elements of the

crime.” O’Connor, 874 F.3d at 1151. And that is a question of pure Oklahoma state

law. Singer and the government both acknowledge that the dispositive question in

this appeal is whether, under Oklahoma law, Oklahoma’s state crime of assault and

battery with a dangerous weapon under § 645 applies to victims who are not yet born.

The answer to that question is necessary to resolve Singer’s appeal of his sentence.

Singer’s appeal also requires us to evaluate whether Oklahoma assault and

battery with a dangerous weapon is a “violent felony” under the ACCA. At

sentencing, the district court concluded that Singer’s two Oklahoma state convictions

for assault and battery with a dangerous weapon were “violent felonies” within the

meaning of the ACCA. Because Singer had another violent felony conviction, the

district court ruled that he had three ACCA-predicate convictions, and therefore

sentenced him under the ACCA. Singer contends on appeal that his Oklahoma § 645

convictions are not violent felonies under the ACCA for the same reasons he argues

they do not qualify as crimes of violence under the Guidelines.

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Under controlling Supreme Court precedent, we must analyze that question

using precisely the same “categorical approach” that we are bound to employ in the

Guidelines context. See Mathis v. United States, 579 U.S. 500, 509 (2016).

Therefore, to determine whether an offense is a “violent felony” under the ACCA, we

must “focus solely on whether the elements of the crime of conviction sufficiently

match the elements of” the predicate offense in the ACCA, “while ignoring the

particular facts of the case.” Id. at 504.

Adams controls our analysis of this ACCA question, too. A “violent felony”

under the ACCA is “any crime punishable by imprisonment for a term exceeding one

year . . . that . . . 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). As

Singer, the government, and the district court agree, the ACCA and the Guidelines

are identical in the only way relevant here—they both concern crimes against “the

person of another.” Compare 18 U.S.C. § 924(e)(2)(B)(i), with U.S.S.G. § 4B1.2(a).

Accordingly, as Singer and the government agree, our precedent in Adams prescribes

our analysis of what constitutes a “violent felony” under the ACCA.

Therefore, Singer’s appeal of the district court’s ACCA ruling also turns on

the elements of Singer’s state-law offenses. If the Oklahoma state crime of assault

and battery with a dangerous weapon extends to victims who are unborn persons,

then Singer’s two convictions for that crime are not categorically violent felonies

under the ACCA, and they cannot serve as predicate offenses for sentencing under

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the ACCA. That state-law question is once again dispositive of Singer’s appeal of

his sentence.

B.

The state-law question at issue in this appeal is clearly novel. Neither

Oklahoma’s Constitution, nor its statutes, nor its courts have squarely addressed it. 1

Moreover, there are compelling arguments in both directions. Still, the Oklahoma

Court of Criminal Appeals’s opinions offer us a “reasonably clear and principled

course” to resolve this question in Singer’s favor. Pino v. United States, 507 F.3d

1233, 1236 (10th Cir. 2007).

The Court of Criminal Appeals has twice had occasion to consider whether

unborn persons are “human beings” such that they can be victims of a crime. The

Court of Criminal Appeals first addressed this question in Hughes v. State, 868 P.2d

730 (Okla. Crim. App. 1994). Hughes concerned the homicide statute then in effect

in Oklahoma, Okla. Stat. tit. 21, § 691 (1981). See 868 P.2d at 731. In Hughes, the

Court of Criminal Appeals held that “whether or not it is ultimately born alive, an

unborn fetus that was viable at the time of injury is a ‘human being,’” and thus falls

within the statutory definition of “Homicide” as “the killing of one human being by

1 We note here that the district court determined that it was bound by our holding in Taylor. However, in Taylor, we did not consider the specific issue of whether Oklahoma law criminalizes the assault and battery of unborn persons with a dangerous weapon. The government concedes as much, stating that our opinion in Taylor “did not squarely address whether Okla. Stat. tit. 21, § 645 was categorically not a crime of violence because it covered unborn victims.” Aple. Br. at 3 n.2. Thus, our analysis here is not impacted by Taylor. 8 Appellate Case: 23-6120 Document: 56-1 Date Filed: 01/23/2026 Page: 9

another.” Id. (quoting Okla. Stat. tit. 21, § 691 (1981)). The Court of Criminal

Appeals reasoned that “[t]he purpose of Section 691 is, ultimately, to protect human

life,” that “[a] viable human fetus is nothing less than human life,” and that “[a]n

offspring of human parents cannot reasonably be considered to be other than a human

being.” Id. at 734 (internal quotation marks and citations omitted). Therefore, the

court held, “the term ‘human being’ in Section 691—according to its plain and

ordinary meaning—includes a viable human fetus.” Id. Likewise, the court

overruled a prior decision, which “held that a viable fetus is not a ‘person’ within the

meaning of” Oklahoma’s statute criminalizing assault and battery with a deadly

weapon. Id. (citing Okla. Stat. tit. 21, § 652 (1981)).

A quarter of a century later in State v. Green, 474 P.3d 886 (Okla. Crim. App.

2020), the Court of Criminal Appeals relied on Hughes to reach a similar conclusion

with respect to Oklahoma’s child neglect statute. Id. at 890–91. Referencing

Hughes, the Green court wrote that “just as a viable fetus may be the victim of a

homicide or an assault with a dangerous weapon, so too may he or she be a victim of

child neglect . . . .” Id. at 893. The court reasoned that, like the term “human being,”

the term “child” in the child neglect statute, “according to its plain and ordinary

meaning[,] includes a viable human fetus.” Id. at 891. Therefore, the court

concluded, the child neglect statute criminalized neglect of a viable fetus, not only

neglect of a child who has already been born alive. See id.

The Court of Criminal Appeals has twice considered the question of whether

an unborn person can be the victim of a crime that, by its terms, applies to a “human

9 Appellate Case: 23-6120 Document: 56-1 Date Filed: 01/23/2026 Page: 10

being” or a “person.” And both times, it concluded that an unborn person could be a

victim. Accordingly, we have no reason to believe that, if presented with this same

question a third time, the Court of Criminal Appeals would decide the question any

other way. And so, making our best Erie guess, we conclude that § 645 criminalizes

assault and battery with a dangerous weapon against an unborn person.

In making this prediction, we are cognizant of legitimate countervailing

arguments. First, in Green itself, the court clarified that “the terms ‘person,’ ‘child,’

‘human being,’ and the like . . . have no general or universal meaning within

[Oklahoma’s] statutes.” 474 P.3d at 890. And § 645 is altogether separate from the

other criminal provisions that the Oklahoma Court of Criminal Appeals interpreted in

Green and Hughes. Compare Okla. Stat. tit. 21, § 645 (“Assault, battery, or assault

and battery with dangerous weapon,” in Ch. 20, “Assault and Battery”), with id.

§ 691 (“Homicide defined,” in Ch. 24, “Homicide”), and id. § 652 (“Shooting or

discharging firearm with intent to kill—Use of vehicle to facilitate discharge of

weapon in conscious disregard of safety of others—Assault and battery with deadly

weapon, etc.,” in Ch. 21, “Attempts to Kill”);, and id. § 843.5 (“Child abuse—Child

neglect—Child sexual abuse—Child sexual exploitation—Enabling—Penalties,” in

Ch. 30, “Miscellaneous Offenses Against the Person”). It seems, therefore, that the

Court of Criminal Appeals in Green intentionally reserved for a future date the

question of whether an unborn person can be the victim of a crime in a statute like

§ 645, arguably rendering Hughes and Green inapposite.

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However, our task in the Erie context is not to determine the exact scope of

Oklahoma precedent. Indeed, the fact that we must make an Erie “guess”

presupposes an “absence of explicit guidance from the state courts.” Pehle v. Farm

Bureau Life Ins., 397 F.3d 897, 902 (10th Cir. 2005) (quoting United Parcel Serv.,

Inc. v. Weben Indus., 794 F.2d 1005, 1008 (5th Cir. 1996)). In this context, our goal

is “reach[ing] the result that would probably be reached were the question to be

litigated in a state court.” Cottonwood Mall Shopping Ctr., Inc. v. Utah Power &

Light Co., 440 F.2d 36, 40 (10th Cir. 1971) (quotation omitted). In that inquiry, the

Court of Criminal Appeals’s reasoning in Hughes and Green is clearly relevant to

determine what that same court would do when presented with essentially the same

question. See Stuart v. Colo. Interstate Gas Co., 271 F.3d 1221, 1228 (10th Cir.

2001) (stating we are “free to consider all resources available” to make our Erie

prediction (quotation omitted)); cf. Shawn J. Bayern, Case Interpretation, 36 Fla. St.

U.L. Rev. 125, 145 (2009) (detailing how lower courts infer the intent of higher

courts). Thus, while the government is plainly correct that neither the Hughes nor

Green court “purported to opine on the meaning of ‘person’ in [§ 645],” Aplt. Br. at

14, we are persuaded that, based on the court’s reasoning in those cases, they would

reach the same outcome if presented with the question before us.

Second, the government points us to the statutory history of the crimes at issue

in Hughes as evidence that, when the legislature intends to criminalize conduct

against an unborn child, it does so explicitly. After Hughes, but before Green,

Oklahoma’s legislature amended its laws criminalizing homicide and assault and

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battery with a dangerous weapon with intent to kill. See Okla. Stat. tit. 21, § 652

(assault and battery with a dangerous weapon); id. § 691 (homicide). The amended

laws codified the outcome in Hughes by explicitly extending the statutes to include

crimes against “an unborn child,” but excluded certain acts related to legal abortions

or medical procedures. See id. §§ 652, 691. The government argues that because the

legislature has made no similar amendment to § 645, we “can reasonably conclude

the Oklahoma Legislature intentionally amended the most serious violent felony

statutes—homicide and assault and battery with a deadly weapon—to include the

unborn as possible victims but declined [similarly to] amend a lesser violent felony

like assault and battery with a dangerous weapon.” Aple. Br. at 9.

While the government’s argument is not without merit, we find it less

persuasive than the Court of Criminal Appeals’s nearly on-point caselaw. Based on

the statutory history, an Oklahoma court might reasonably conclude that the

legislature amended the more serious crimes primarily to exclude liability related to

legal abortions and medical procedures, but that the Oklahoma legislature intended to

leave intact broad liability for the less-serious § 645. Or perhaps a court could

conclude that the Oklahoma legislature was responding narrowly and directly to

Hughes, and not thinking about other criminal provisions at all. And in any event,

the absence of the term “unborn” in Oklahoma’s child neglect statute did not prevent

the Court of Criminal Appeals from holding that it extended to unborn persons in

Green, which was decided after the amendments to §§ 652 and 691.

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And, more troublingly for our purposes, relying on this statutory history

requires us to divine through indirect evidence (legislative silence) what we can

determine based on direct evidence (the Court of Criminal Appeals’s decisions in

Hughes and Green). That is always a fraught proposition. Cf. Cent. Bank of Denver,

N.A. v. First Interstate Bank of Denver, N.A., 511 U.S. 164, 187 (1994) (stating that

legislative “inaction lacks persuasive significance because several equally tenable

inferences may be drawn from such inaction” (quotation omitted)); Encino

Motorcars, LLC v. Navarro, 584 U.S. 79, 90 (2018) (“Silence in the legislative

history, no matter how clanging, cannot defeat the better reading of the text and

statutory context.” (cleaned up)). Deciding this case on the statutory history requires

us to make assumptions both about the meaning of that silence, and about the

persuasive value that the Court of Criminal Appeals would afford that silence. We

are not best positioned to muse about the meaning of legislative silence in

interpreting Oklahoma law. By contrast, deciding this case as we do today requires

us only to extend the logic of two Court of Criminal Appeals cases that are nearly,

but not perfectly, on point. Framed in this way, we believe the “clear and principled

course” to resolve this question is to apply the Court of Criminal Appeals’s reasoning

in Hughes and Green and hold that § 645 criminalizes the assault and battery with a

dangerous weapon of an unborn person. Pino, 507 F.3d at 1236. 2

2 The government further argues that Oklahoma’s Uniform Jury Instructions militate for finding that § 645 does not apply to an unborn person. The government’s argument to that end tracks with its argument about statutory silence: it asserts that because courts give a jury instruction that “a person/(human being) shall include an 13 Appellate Case: 23-6120 Document: 56-1 Date Filed: 01/23/2026 Page: 14

C.

Tying everything together, because § 645 criminalizes the assault and battery

with a dangerous weapon of an unborn person, it is not a “crime of violence” under

the Guidelines or the ACCA. This follows from our decision in Adams in which we

held that if a state crime “allows a conviction . . . when the victim is a fetus,” there is

a “mismatch” between “the elements of the state crime and the guidelines’ definition

of a crime of violence.” Id. at 1170–71 (emphasis in original). And, under the

categorical approach, where such a mismatch exists, the state crime is not a “crime of

violence” for Guidelines purposes, id., or ACCA purposes, see Mathis, 579 U.S. at

509.

Finally, because § 645 convictions are not convictions for crimes of violence

under the Guidelines or under the ACCA, the district court erred in calculating

Singer’s sentence to the extent it increased his sentence by classifying his § 645

convictions as crimes of violence.

unborn child” in §§ 652 and 691 cases, but omit that instruction for § 645 cases, then § 645 must not criminalize conduct against unborn people. Aple. Br. at 10 (quoting Okla. Unif. Instr. 4-57). It is true that “jury instructions provide useful guidance on the content of state law.” United States v. Hamilton, 889 F.3d 688, 693 (10th Cir. 2018). However, this argument suffers the same pitfalls as the argument about statutory silence. First, the Uniform Jury Instructions are intended to track the elements of the underlying criminal statute. Thus, any silence in the Uniform Jury Instructions has only the same, but not greater, persuasive value as the silence in the statute. Second, and illustrative of the first point, the child neglect statute at issue in Green did not expressly include an “unborn child” in the relevant jury instructions. See Okla. Unif. Inst. 4-37. 14 Appellate Case: 23-6120 Document: 56-1 Date Filed: 01/23/2026 Page: 15

IV.

For the foregoing reasons, we REVERSE the district court and REMAND for

resentencing consistent with this opinion.

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23-6120, United States v. Singer

MATHESON, Circuit Judge, concurring in the judgment.

I concur in the judgment based on the uncertain scope of Okla. Stat. tit. 21

§ 645. See United States v. Degeare, 884 F.3d 1241, 1244 (10th Cir. 2018) (stating

“we must be certain that the violent-felony moniker necessarily applies to a particular

offense before we can treat that offense as an ACCA predicate.” (quotations

omitted)).