PUBLISH 

UNITED STATES COURT OF APPEALS 

FOR THE TENTH CIRCUIT 

_________________________________ 

UNITED STATES OF AMERICA, 

 Plaintiff - Appellee, 

v. 

CONNER LEE POLK, 

 Defendant - Appellant. 

No. 22-5037 

_________________________________ 

Appeal from the United States District Court 

for the Northern District of Oklahoma 

(D.C. No. 4:21-CR-00294-GKF-1)

_________________________________ 

Andrew M. Casey of Hendrick, Casey, Hutter, PLLC, Oklahoma City, Oklahoma 

(Shannon M. McMurray of Viridian Legal Services, PLLC, Tulsa, Oklahoma, with him 

on the briefs), for Defendant-Appellant. 

Leena Alam, Assistant United States Attorney (Clinton J. Johnson, United States 

Attorney, Chantelle Dial, Assistant United States Attorney, on the briefs), United States 

Attorney’s Office, Northern District of Oklahoma, Tulsa, Oklahoma, for PlaintiffAppellee. 

_________________________________ 

Before MORITZ, SEYMOUR, and EID, Circuit Judges. 

_________________________________ 

MORITZ, Circuit Judge. 

_________________________________ 

Conner Lee Polk appeals his four-year prison sentence under the Assimilative 

Crimes Act (ACA), 18 U.S.C. § 13, for committing a state-law offense on an Indian 

FILED 

United States Court of Appeals 

Tenth Circuit 

March 13, 2023

Christopher M. Wolpert 

Clerk of Court

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reservation in Oklahoma. Polk argues that the district court should have considered 

imposing a shorter prison term under an Oklahoma statute that permits a departure 

from a mandatory minimum sentence in certain circumstances. Because this state law 

conflicts with federal sentencing policy, the district court properly declined to apply 

it, and we affirm Polk’s sentence. 

Background 

In December 2019, Polk crashed his pickup truck into two cars while 

intoxicated, seriously injuring occupants in one of the vehicles. Because this conduct 

occurred on an Indian reservation and Polk is an Indian, a federal prosecution ensued 

under the ACA. As explained in more detail later, the ACA applies to acts committed 

on an Indian reservation that are crimes in the state within which the reservation is 

located—here, Oklahoma—but are not otherwise crimes under federal law. See

§ 13(a). The government charged Polk under the ACA with an Oklahoma DUI 

offense that carries a mandatory prison sentence of at least 4 years and at most 20 

years. See Okla. Stat. tit. 47, § 11-904(B)(1). He eventually pleaded guilty to that 

offense.1

Despite the mandatory minimum applicable to his offense, Polk at sentencing 

requested a prison term of less than four years. For support, he cited Oklahoma’s 

“safety-valve” law, which allows state-court judges in certain circumstances to 

1

 Polk also pleaded guilty to an ACA offense for involvement in an accident 

that damaged a vehicle, see Okla. Stat. tit. 47, § 10-103, for which he received a 

concurrent six-month prison sentence. He does not challenge his conviction or 

sentence for this offense. 

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impose a sentence below a statutory mandatory minimum. See Okla. Stat. tit. 22, 

§ 985.1(A). The district court, however, concluded that it could not apply 

Oklahoma’s safety-valve law because that provision conflicts with federal sentencing 

provisions that permit federal courts to depart from statutory mandatory minimums 

only in two limited circumstances, neither of which exists here. See 18 U.S.C. 

§ 3553(e)–(f). Given this conflict, the district court sentenced Polk to the four-year 

mandatory minimum prison term. 

Analysis 

Polk appeals his sentence, arguing that the district court erred in declining to 

apply Oklahoma’s safety-valve law to consider whether he qualified for a departure 

below the four-year mandatory minimum. That argument hinges on whether the 

district court properly interpreted the ACA, the relevant federal sentencing 

provisions, and Oklahoma’s safety-valve law. We review those legal determinations 

de novo. See United States v. Chapman, 839 F.3d 1232, 1241 (10th Cir. 2016).

As relevant here, the ACA provides federal jurisdiction over certain criminal 

acts committed on Indian reservations.2 United States v. Garcia, 893 F.2d 250, 253 

2

 By its terms, the ACA applies only to crimes committed on federal 

enclaves—“areas where states have ceded jurisdiction over land within their borders 

to Congress, such as military bases, federal facilities, and national parks and forests.” 

United States v. Harris, 10 F.4th 1005, 1010 (10th Cir. 2021). It applies to crimes on 

Indian reservations by way of 18 U.S.C. § 1152, which extends federal-enclave law 

to Indian country, see United States v. Langford, 641 F.3d 1195, 1197 (10th Cir. 

2011) (explaining that “in conjunction,” ACA and § 1152 “(1) assimilate state 

criminal law into federal law” for acts committed on federal enclaves and “(2) apply 

these assimilated state crimes to acts committed in Indian country”). 

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(10th Cir. 1989). When such acts occur, they are often prohibited by specific federal 

criminal statutes. For instance, the Major Crimes Act, 18 U.S.C. § 1153(a), 

proscribes a list of severe offenses, such as murder and kidnapping, that are federal 

crimes when committed by Indians in Indian country. But sometimes, as is the case 

here, no particular federal statute covers the defendant’s conduct, meaning it would 

not otherwise be a federal crime. United States v. Jones, 921 F.3d 932, 935 (10th Cir. 

2019). In that event, the ACA steps in and generates a federal offense using the laws 

of the state in which the relevant reservation is located. See id. More precisely, it 

allows federal courts to “borrow [the relevant crime] from preexisting state law,” 

thereby creating an applicable federal offense to fill the gap in the U.S. Code. United 

States v. Christie, 717 F.3d 1156, 1170 (10th Cir. 2013); cf. also United States v. 

Martinez, 1 F.4th 788, 790 (10th Cir. 2021) (explaining that “[t]he assimilated state 

offense becomes a federal offense punishable under federal law”), cert. denied, 142 

S. Ct. 1373 (2022). 

Notably, however, the ACA does not require federal courts to incorporate 

every aspect of state criminal law that may apply to the newly created offense. See 

Christie, 717 F.3d at 1171–72. To the contrary, it requires only that they ensure the 

defendant receives a “like punishment,” § 13(a)—one similar to the punishment he or 

she would receive in state court. See Christie, 717 F.3d at 1171–72 (emphasizing that 

“the ACA requires like punishment, not precisely the same punishment”). Typically, 

this like-punishment standard means that we must apply “any maximum and 

minimum prison terms pr[e]scribed by state law for an assimilated crime.” Id. at 

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1171. But in imposing a sentence between those mandatory values, federal courts 

need not “duplicate every last nuance of the sentence that would be imposed in state 

court.” Id. at 1172 (quoting Garcia, 893 F.2d at 254). And critically, “federal courts 

must depart from state [sentencing laws] when Congress has expressed a specific and 

contrary penal policy.” Id.; see also United States v. Wood, 386 F.3d 961, 963 (10th 

Cir. 2004) (“[W]hen sentencing defendants for assimilated crimes, federal courts 

have consistently declined to assimilate state sentencing laws if such laws conflict 

with the [United States Sentencing] Guidelines and their underlying policies.”). 

Applying this principle, the district court concluded that it could not sentence 

Polk under the Oklahoma safety-valve law because that law conflicts with federal 

sentencing policy, in particular 18 U.S.C. § 3553(e) and (f). Polk disputes this 

conclusion, arguing that no such conflict exists and that the district court therefore 

should have incorporated Oklahoma’s safety-valve law and considered imposing a 

prison term of less than four years. 

But Polk does not meaningfully grapple with the district court’s reasons for 

finding a conflict. As the district court explained, under § 3553, federal sentencing 

judges may “depart from a mandatory minimum sentence only in [two] enumerated, 

limited circumstances,” neither of which applies here.3

 App. vol. 1, 41; see also 

United States v. C.D., 848 F.3d 1286, 1292 & n.5 (10th Cir. 2017) (noting that 

3

 As the district court also noted, the Guidelines similarly permit such 

departures only in the two circumstances outlined in § 3553(e) and (f). See U.S.S.G. 

§§ 5C1.2, 5K1.1. 

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§ 3553 contains the “only two congressionally-authorized exceptions to a mandatory 

minimum sentence” (emphasis added)). Specifically, they may do so only when the 

defendant (1) provides substantial assistance to a criminal investigation or 

prosecution, or (2) is convicted of certain listed drug offenses and satisfies five 

statutory factors. § 3553(e)–(f). Oklahoma’s safety-valve law, on the other hand, 

allows departures from mandatory minimums under a broader set of circumstances. 

See Okla. Stat. tit. 22, § 985.1(A) (permitting departure for certain qualifying 

offenses when mandatory minimum “is not necessary for the protection of the 

public,” “would result in substantial injustice to the defendant,” or “is not necessary 

for the protection of the public and the defendant . . . has been accepted” to 

alternative court, diversion program, or community sentencing). Thus, as the district 

court concluded, Oklahoma’s safety-valve law conflicts with federal sentencing 

policy because it would allow a prison term below the mandatory minimum in 

circumstances other than those exclusively provided for in § 3553(e) and (f).4

 Polk’s contrary argument does not undermine this straightforward textual 

conclusion. He suggests that the district court erred by basing its conclusion that a 

conflict exists on a determination that the federal safety-valve provision, § 3553(f), 

4

 This direct tension between what state law permits and what federal law 

forbids answers Polk’s assertion, drawn from an analogy to the conflict-preemption 

doctrine, that two laws do not conflict if they merely “overlap” and that a conflict 

instead requires that it be “[im]possible to comply with both” laws. Rep. Br. 6 

(quoting Kansas v. Garcia, 140 S. Ct. 791, 806 (2020)). This impossibility standard 

plainly is met here: Both provisions cannot be given effect because, as mentioned 

above, Oklahoma’s safety-valve law allows departures for reasons that would not 

support a departure under § 3553(e) and (f). 

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“never references” the ACA specifically. Aplt. Br. 25–26. From that premise, Polk 

then argues that no language in § 3553(f) shows that Congress intended “to exclude 

[the ACA] from [federal] safety[-]valve consideration.” Rep. Br. 3. But this argument 

both misunderstands and fails to refute the district court’s conflict analysis. As 

explained, the district court did not base its conclusion that Oklahoma’s safety-valve 

law conflicts with § 3553 on Congress’s failure to mention the ACA in subsection (f) 

(or subsection (e), for that matter).5

 Instead, it based that conclusion on the fact that 

Oklahoma’s safety-valve law would allow departures below the mandatory minimum 

in circumstances beyond those provided for in § 3553(e) and (f). Nothing about 

Polk’s § 3553(f) argument disputes this unambiguous conflict, and this conflict is 

fatal to Polk’s sentencing challenge.6 See Christie, 717 F.3d at 1172. 

Conclusion

In sum, because Oklahoma’s safety-valve law conflicts with federal sentencing 

5

 To the extent that this failure to mention the ACA in the federal safety-valve 

provision has any significance, it suggests that Congress did intend to exclude ACA 

offenses because § 3553(f) specifies that it applies only “in the case of” certain 

enumerated drug offenses. See Navajo Nation v. Dalley, 896 F.3d 1196, 1213 (10th Cir. 

2018) (“[T]he enumeration of certain things in a statute suggests that the legislature had 

no intent of including things not listed or embraced” (quoting Seneca-Cayuga Tribe of 

Okla. v. Nat’l Indian Gaming Comm’n, 327 F.3d 1019, 1034 & n.24 (10th Cir. 2003))). 

6

 Because the relevant statutory language is unambiguous, we do not address 

Polk’s arguments about legislative history, statutory purpose, and the rule of lenity 

supporting his position. See In re Geneva Steel Co., 281 F.3d 1173, 1178 (10th Cir. 

2002) (noting that courts must interpret an unambiguous statute “according to its 

plain meaning,” considering legislative history and statutory purpose only “[i]f a 

statute is ambiguous”); United States v. Black, 773 F.3d 1113, 1117 (10th Cir. 2014) 

(requiring showing of “grievous ambiguity or uncertainty in the statute” to apply rule 

of lenity (quoting Dean v. United States, 556 U.S. 568, 577 (2009))). 

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policy—specifically, § 3553(e) and (f)—the district court did not err in declining to 

apply that state law when sentencing Polk. Instead, the district court properly 

incorporated only the state-law mandatory minimum applicable to Polk’s crime, 

thereby providing him with the “like punishment” the ACA requires. § 13(a). Thus, 

we affirm Polk’s sentence. 

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