People v. Kennedy (2025 CO 63): Vehicular Homicide–DUI Is Not Per Se “Grave or Serious” for Colorado Proportionality Review

I. Introduction

Case: People v. Kennedy, 2025 CO 63 (Colorado Supreme Court, Dec. 15, 2025).
Parties: The People of the State of Colorado (petitioner/cross-respondent) vs. Kari Mobley Kennedy (respondent/cross-petitioner).
Posture: Post-conviction appeal challenging the constitutionality of a prison sentence under the Cruel and Unusual Punishments Clauses of the U.S. and Colorado Constitutions.

The case arises from a fatal drunk-driving crash in which Kennedy, severely intoxicated, crossed into oncoming traffic, killed another driver, and seriously injured two passengers (including partial paralysis). Kennedy pleaded guilty to vehicular homicide–DUI under section 18-3-106(1)(b)(I), C.R.S. (2025), and vehicular assault–DUI, and accepted an agreed sentencing range. The trial court imposed consecutive sentences, including twenty-four years for vehicular homicide–DUI (aggravated maximum) plus five years for vehicular assault–DUI.

Two issues dominated the appeal:

1. Whether vehicular homicide–DUI is a per se “grave or serious” crime for Colorado proportionality review (a designation that short-circuits the “gravity” inquiry).
2. Whether Kennedy’s sentence nevertheless raises an inference of gross disproportionality entitling her to an extended proportionality review.

The court of appeals held the offense is not per se grave or serious but still affirmed the sentence, disagreeing with People v. Strock and producing an intra-court-of-appeals split. The Colorado Supreme Court granted certiorari and used the case to clarify the Wells-Yates framework as applied to strict-liability homicide by DUI.

II. Summary of the Opinion

The Colorado Supreme Court affirmed. It held:

• Vehicular homicide–DUI is not per se “grave or serious” for proportionality-review purposes because it is a strict liability offense requiring no mens rea, and mens rea is a “key gauge” of culpability in the per se analysis.
• Considering the facts of Kennedy’s case—death, catastrophic injuries, very high BAC, repeated DUI history, and failure at rehabilitation—the sentence does not raise an inference of gross disproportionality, so Kennedy is not entitled to extended proportionality review.
• To the extent conflicting court of appeals decisions existed (e.g., People v. Strock), they are overruled.

III. Analysis

A. Precedents Cited (and How They Shaped the Holding)

1. The constitutional baseline and two-step proportionality structure

• Solem v. Helm, 463 U.S. 277 (1983): Supplies the canonical two-step proportionality structure. Step one compares gravity to harshness; step two (triggered only if step one yields an inference of gross disproportionality) compares sentences intrajurisdictionally and interjurisdictionally. The court expressly anchors Colorado’s “abbreviated” and “extended” nomenclature in Solem.
• Harmelin v. Michigan, 501 U.S. 957 (1991) (Kennedy, J., concurring): Reinforces that the Eighth Amendment proportionality principle is framed around gross disproportionality. The majority cites the “grossly disproportionate” standard through Harmelin’s influential concurrence.
• Close v. People, 48 P.3d 528 (Colo. 2002), abrogated on other grounds by, Wells-Yates v. People: Provides Colorado’s labels “abbreviated proportionality review” and “extended proportionality review,” and is referenced for the mechanics of ending the inquiry when no inference arises.

2. Colorado’s “per se grave or serious” shortcut, refined

• Wells-Yates v. People, 2019 CO 90M, 454 P.3d 191: The controlling authority for when an offense can be deemed per se grave or serious. Kennedy relies on Wells-Yates for three core propositions:
  1. The per se designation is a Colorado-only shortcut used to avoid case-by-case gravity analysis.
  2. It should be used rarely and cautiously because it removes a meaningful layer of review for defendants.
  3. The per se label is appropriate only if, based solely on statutory elements, there is no set of circumstances where the conduct and culpability are not grave/serious.

  The majority treats the inquiry as akin to a facial constitutional challenge, setting up its reliance on the “no set of circumstances” framing from United States v. Salerno.

• United States v. Salerno, 481 U.S. 739 (1987): Supplies the “no set of circumstances” idea that the majority analogizes to the per se grave-or-serious test—if any factual scenario exists where the offense’s statutory elements could capture non-grave/non-serious culpability, the per se label is improper.
• People v. Gaskins, 825 P.2d 30 (Colo. 1992): Quoted (via Wells-Yates) for the point that gravity determinations can be “somewhat imprecise,” explaining why the shortcut exists—and why using it too broadly is risky.
• McDonald v. People, 2024 CO 75, 560 P.3d 412: Provides the modern list of gravity factors and reiterates which offenses remain per se grave or serious after Wells-Yates. Kennedy uses McDonald both as a standard-of-review anchor and as a taxonomy of the remaining per se crimes (robbery, burglary, etc.), underscoring that per se status is reserved for crimes that reliably include culpable mental states and grave harm.

3. Deference to legislative sentencing schemes and parole considerations

• People v. Gross, 830 P.2d 933 (Colo. 1992): Establishes that statutorily authorized sentencing regimes are presumed constitutional.
• Rutter v. People, 2015 CO 71, 363 P.3d 183: Supports the proposition that sentences within the authorized range “likely won’t” raise an inference of gross disproportionality.
• People v. Drake, 785 P.2d 1257 (Colo. 1990), abrogated on other grounds as recognized by, People v. Chavez-Barragan, 2016 CO 66, 379 P.3d 330: Used for the proposition that parole eligibility reduces harshness and therefore reduces the likelihood of an inference of gross disproportionality.

4. The split below and the Court’s corrective function

• People v. Kennedy, 2023 COA 83M, 541 P.3d 11: The decision under review, which held vehicular homicide–DUI is not per se grave or serious but affirmed the sentence.
• People v. Strock, 252 P.3d 1148 (Colo. App. 2010): Identified as part of the inter-division conflict. The supreme court explicitly states that to the extent its holding conflicts with certain court of appeals opinions, “those opinions are overruled,” citing Strock as an example.

5. Authorities highlighted in concurrences (context and doctrinal tension)

Although the majority’s holding is narrow, the concurrences illuminate the doctrinal pressure points:

• People v. Rostad, 669 P.2d 126 (Colo. 1983): Central to Justice Boatright’s view that strict liability still contains a minimum “voluntary act” requirement, suggesting a kind of culpability sufficient for per se status.
• Mitchell v. Wisconsin, 588 U.S. 840 (2019); Birchfield v. North Dakota, 579 U.S. 438 (2016); Breithaupt v. Abram, 352 U.S. 432 (1957); South Dakota v. Neville, 459 U.S. 553 (1983); Tate v. Short, 401 U.S. 395 (1971): Used in the concurrence to emphasize the public-safety stakes and societal condemnation of drunk driving.
• People v. Hulse, 557 P.2d 1205 (Colo. 1976): Invoked to support legislative deference in motor-vehicle-death contexts and to frame DUI harms as a “specific evil” of “greater societal consequence.”
• People v. Rigsby, 2020 CO 74, 471 P.3d 1068; Randolph v. People, 2025 CO 44, 570 P.3d 1022: Cited in the concurrence for Colorado’s mental-state hierarchy and the legislature’s primacy in defining mens rea requirements.
• People v. Deroulet, 48 P.3d 520 (Colo. 2002), abrogated on other grounds by, Wells-Yates v. People: Cited to contextualize what offenses have historically been considered per se grave/serious.
• People v. Johnson, 142 P.3d 722 (Colo. 2006): Appears in Justice Samour’s retroactivity note while questioning whether the per se framework should exist at all.

B. Legal Reasoning (How the Court Got to the Rule)

1. The new clarification: strict liability and the per se designation

The opinion’s central doctrinal move is to tie per se “grave or serious” status to the ability to assess culpability from statutory elements in every case. Under the statute, vehicular homicide–DUI requires: operation of a motor vehicle while under the influence, proximately causing death. It is expressly a strict liability crime (no mens rea required).

The court treats mens rea as a “key gauge of culpability during sentencing.” Without a mens rea element, the court concludes, it is “impossible to evaluate the culpability of defendants convicted of the offense under every factual scenario,” which is fatal to per se status under Wells-Yates’s “rare crimes” approach.

Notably, the court does not say vehicular homicide–DUI is not grave or serious; it says it is not always categorically grave or serious as a matter of elements alone, because culpability cannot be uniformly inferred in the manner required for the per se shortcut.

2. The second holding: no inference of gross disproportionality on these facts

After refusing the per se shortcut, the court performs the “abbreviated” gravity-vs.-harshness comparison and concludes the analysis ends there:

• Gravity: Kennedy’s conduct caused death and severe, life-altering injuries; her BAC remained extraordinarily high hours later; she had a repeated DUI history (fourth DUI); and she struggled to abstain even after release.
• Harshness: The 24-year sentence was within the statutorily authorized range, was within the plea-agreed range, and carried parole eligibility.

Given legislative deference and the individualized aggravating circumstances, the court finds no inference of gross disproportionality, so Kennedy is not entitled to the extended comparative step.

3. What the concurrences reveal about the doctrine

Justice Boatright’s concurrence (joined by Chief Justice Márquez) frames the dispute as fundamentally moral and harm-based: death-by-drunk-driving is inherently grave enough to be per se, regardless of intent, and strict liability reflects the legislature’s judgment that voluntariness suffices. Justice Samour’s special concurrence, by contrast, suggests the per se category should be eliminated entirely, calling it unsupported by U.S. Supreme Court doctrine and potentially unfair because it makes proportionality challenges “all but impervious” once the label applies.

The majority does not adopt either concurrence’s broader proposal; it instead issues a narrower rule: strict liability (no mens rea) defeats per se status for this offense.

C. Impact (What Changes After People v. Kennedy)

1. Direct doctrinal impact in Colorado proportionality litigation

• Vehicular homicide–DUI cannot be treated as automatically grave/serious at the threshold stage of an abbreviated proportionality review.
• Trial courts must conduct an ad hoc gravity analysis (rather than skipping directly to sentence harshness) when defendants seek proportionality review for vehicular homicide–DUI.
• The court’s express overruling “to the extent” of conflict resolves the court-of-appeals split and undercuts reliance on People v. Strock for per se treatment of this offense.

2. Practical impact: more threshold analysis, but not necessarily more relief

The decision does not meaningfully lower sentences or create a new constitutional ceiling; it changes the analytic pathway. Many vehicular homicide–DUI cases will still be found grave and the sentences upheld—especially in high-BAC or recidivist situations—because the court’s second holding demonstrates how easily the gravity-harshness comparison can end the case without extended review.

3. Broader implication: strict liability as a limiting principle on per se designations

While the opinion is formally confined to vehicular homicide–DUI, its reasoning signals a more general constraint: where the statutory elements omit mens rea, the court is reluctant (perhaps categorically unwilling) to confer the per se label. That matters for any strict-liability offense that might be argued to be inherently grave based on harm alone.

IV. Complex Concepts Simplified

• Proportionality review: A constitutional check asking whether a sentence is so extreme compared to the crime that it becomes “cruel and unusual.”
• Abbreviated vs. extended review: “Abbreviated” is the first-screen comparison (gravity vs. harshness). “Extended” happens only if the first screen suggests the sentence might be grossly disproportionate, and then compares sentences across crimes and jurisdictions.
• Per se grave or serious: A Colorado shortcut: if a crime is always grave/serious based solely on its elements, courts skip directly to evaluating the sentence’s harshness. Kennedy narrows this shortcut by rejecting it for vehicular homicide–DUI.
• Mens rea: The mental state required for guilt (e.g., intentionally, knowingly, recklessly). The majority treats mens rea as a key indicator of culpability for deciding whether a crime can be per se grave/serious.
• Strict liability offense: A crime that does not require proof of mens rea. Under Kennedy, that absence prevents courts from confidently treating the offense as always grave/serious for proportionality “per se” purposes.
• Inference of gross disproportionality: A threshold signal that the sentence might be unconstitutionally extreme—needed to unlock the extended comparative analysis.

V. Conclusion

People v. Kennedy establishes a clear Colorado rule: vehicular homicide–DUI is not per se grave or serious for proportionality-review purposes because it is a strict liability offense lacking a mens rea element, which the court views as essential to uniformly assessing culpability across all possible cases. At the same time, the court underscores that the absence of per se status does not imply leniency: applying the ordinary, fact-specific abbreviated review, it holds that Kennedy’s twenty-four-year sentence does not raise an inference of gross disproportionality in light of the catastrophic harm, extreme intoxication, and recidivism.

The decision’s enduring significance lies in its re-calibration of Colorado’s distinctive per se shortcut: it preserves the shortcut in theory (despite invitations to expand it or abolish it), but constrains its reach by insisting that per se gravity requires an elements-based, across-the-board culpability assessment that strict liability statutes cannot provide.