Limiting the “Per Se Grave or Serious” Doctrine: People v. Kennedy and Vehicular Homicide–DUI

I. Introduction

In People v. Kennedy, 2025 CO 63, the Colorado Supreme Court confronted a recurring and difficult question in proportionality jurisprudence: when may a sentencing court treat a particular offense as “per se grave or serious”, thereby short‑circuiting the usual gravity analysis in an Eighth Amendment / article II, § 20 review?

The case arose from a tragic incident: Kari Mobley Kennedy, driving with a blood alcohol content more than three times the legal limit and with a history of prior DUI convictions, crossed into oncoming traffic, killing a young driver and severely injuring two passengers, one of whom was left partially paralyzed. Kennedy pleaded guilty to vehicular homicide–DUI and vehicular assault–DUI and accepted a sentencing range of eight to thirty‑three years. The trial court imposed a total of twenty‑nine years, including twenty‑four years for vehicular homicide–DUI, the maximum in the aggravated range.

Kennedy later sought proportionality review, arguing her sentence was unconstitutionally grossly disproportionate. The case presented two central issues:

1. At the doctrinal level: Is vehicular homicide–DUI under section 18‑3‑106(1)(b)(1), C.R.S. (2025), a per se grave or serious offense for purposes of proportionality review?
2. At the case‑specific level: Was Kennedy’s twenty‑four‑year vehicular homicide–DUI sentence grossly disproportionate to her offense and thus unconstitutional?

The Colorado Court of Appeals had held that vehicular homicide–DUI is not per se grave or serious, expressly disagreeing with an earlier division’s decision in People v. Strock, 252 P.3d 1148 (Colo. App. 2010), and nonetheless upheld Kennedy’s sentence as constitutional. The Supreme Court granted certiorari on both parties’ petitions to resolve the conflict and to decide Kennedy’s proportionality challenge.

II. Summary of the Opinion

A. Holdings of the Court

Majority opinion (Justice Hood, joined by Justices Gabriel, Samour, and Berkenkotter)

1. Vehicular homicide–DUI is not per se grave or serious.
   The court holds that vehicular homicide–DUI, a strict‑liability offense requiring no proof of mens rea, cannot be designated per se grave or serious for proportionality purposes. The court emphasizes that:
   • Mens rea is a “key gauge of culpability” in assessing the gravity of an offense.
   • Because vehicular homicide–DUI has no mental‑state element, courts cannot say that every conviction under the statute necessarily reflects grave or serious culpability across “all factual scenarios.”
   • Colorado has never designated a strict‑liability crime as per se grave or serious; the court declines to be the first to do so.
   • This holding explicitly disapproves contrary Court of Appeals decisions, including Strock.
2. Kennedy’s twenty‑four‑year vehicular homicide–DUI sentence is not grossly disproportionate.
   Applying an abbreviated proportionality review, the court concludes Kennedy’s sentence does not raise an inference of gross disproportionality in light of:
   • the extreme harm (death and severe long‑term injury),
   • her extraordinarily high BAC,
   • her history of multiple prior DUIs and failed rehabilitation efforts (including conduct while on bond),
   • the fact that the sentence is within the statutorily authorized aggravated range,
   • her own agreement to a range encompassing twenty‑four years as part of a plea bargain, and
   • the availability of parole.
   Because no inference of gross disproportionality arises, the court holds Kennedy is not entitled to an extended proportionality review.

The judgment of the court of appeals is affirmed.

B. Concurring Opinions

• Justice Boatright, joined by Chief Justice Márquez (concurring in part and in the judgment)
  Agrees the sentence is constitutional, but sharply disagrees with the majority’s refusal to classify vehicular homicide–DUI as per se grave or serious. For him, the combination of:
  • the defendant’s voluntary choice to drink to excess and then drive, and
  • the inevitable result of a death
  makes every instance of vehicular homicide–DUI inherently grave and serious, regardless of the absence of a conventional mens rea element.
• Justice Samour, joined by Justice Gabriel (specially concurring)
  Fully concurs in the majority’s analysis and result, but writes separately to urge that Colorado should abandon the entire “per se grave or serious” category in future cases. He notes:
  • The per se doctrine is unique to Colorado and has no counterpart in U.S. Supreme Court proportionality jurisprudence.
  • It threatens to make many sentences “all but impervious” to proportionality challenges by allowing courts to bypass scrutiny of the crime’s gravity.
  • The supposed efficiency gains are minimal compared to the doctrinal problems and fairness concerns.
  Because the issue was not squarely before the court or fully briefed, he treats his analysis as an invitation for future reconsideration.
• Justice Hart did not participate.

III. Doctrinal and Precedential Background

A. Constitutional Proportionality Review

Both the Eighth Amendment and article II, § 20 of the Colorado Constitution prohibit “cruel and unusual” punishments. A term‑of‑years sentence violates these provisions only if it is “grossly disproportionate” to the offense. This framework stems from U.S. Supreme Court cases:

• Solem v. Helm, 463 U.S. 277 (1983) – articulates the basic two‑step proportionality analysis.
• Harmelin v. Michigan, 501 U.S. 957 (1991) – confirms that gross disproportionality is the controlling standard (Justice Kennedy’s concurrence is especially influential).

Colorado has adopted Solem’s two‑step structure, using the terminology of abbreviated and extended proportionality review:

1. Abbreviated review (step one) – The court:
   • assesses the gravity or seriousness of the offense, and
   • compares it to the harshness of the penalty.
   Only if this comparison gives rise to an inference that the sentence is grossly disproportionate does the court proceed to the second step.
2. Extended review (step two) – The court compares:
   • the challenged sentence with sentences for other crimes in the same jurisdiction, and
   • sentences for the same crime in other jurisdictions.

Colorado cases such as Close v. People, 48 P.3d 528 (Colo. 2002), Wells‑Yates v. People, 2019 CO 90M, and McDonald v. People, 2024 CO 75, refine this framework and supply the now‑canonical list of factors used to gauge the gravity of an offense.

B. The Gravity Factors: From Solem to McDonald

Drawing on Solem, McDonald reiterates that assessing the “gravity or seriousness” of an offense typically turns on seven interrelated factors:

1. Harm caused or threatened to the victim or society;
2. Whether the offense involved violence or the threat of violence;
3. The “absolute magnitude” of the crime;
4. Whether the offense is a lesser‑included or greater offense;
5. Whether the offense is an attempted or completed crime;
6. The defendant’s role (principal, complicitor, accessory); and
7. The defendant’s culpability and motive (including mens rea).

The majority in Kennedy relies heavily on factor (7), emphasizing that mens rea is crucial to culpability and thus to gravity.

C. The Colorado‑Specific “Per Se Grave or Serious” Doctrine

Colorado has overlaid the Solem framework with a unique innovation: the “per se grave or serious” designation. As clarified in Wells‑Yates:

• A crime is per se grave or serious only if, based solely on its statutory elements, it “necessarily involves grave or serious conduct in every potential factual scenario.”
• For such crimes, courts may skip directly to assessing the harshness of the penalty in abbreviated review, because the gravity of the offense is conclusively presumed.
• Examples that remain per se grave or serious (post‑Wells‑Yates) include aggravated robbery, robbery, burglary and related inchoate forms, felony menacing, accessory to first degree murder, and sale or distribution of narcotics.

But Wells‑Yates also sharply narrowed the doctrine:

• Per se labels must be used cautiously and only for “rare” crimes.
• Courts should be especially wary where legislative amendments suggest a softened view of the offense’s seriousness.
• Most importantly, the per se label has serious due process consequences, because it usually makes a statutorily authorized sentence “all but impervious” to proportionality challenges.

McDonald later held that these limits in Wells‑Yates applied retroactively in the sense of governing how proportionality reviews are conducted, but did not retroactively invalidate sentences.

D. Vehicular Homicide and Prior Colorado Cases

Colorado law distinguishes between:

• Reckless vehicular homicide – where death is caused by reckless driving.
• Vehicular homicide–DUI – where death is caused by driving “under the influence” of alcohol or drugs, a strict‑liability offense under § 18‑3‑106(1)(b)(1).

Key precedents include:

• People v. Hulse, 557 P.2d 1205 (Colo. 1976)
  Upheld the General Assembly’s decision to punish reckless vehicular homicide more severely than criminally negligent homicide, emphasizing the legislature’s “legitimate interest in discouraging a specific evil” associated with deaths caused through use of a motor vehicle.
• People v. Rostad, 669 P.2d 126 (Colo. 1983)
  Upheld the constitutionality of strict‑liability vehicular homicide–DUI against due process challenges. Rostad held that:
  • Strict‑liability offenses still require proof of a voluntary act; they are not “no‑fault” crimes.
  • The General Assembly may, within constitutional limits, criminalize and punish conduct without requiring a conventional culpable mental state.

At the intermediate appellate level, however, divisions split on whether vehicular homicide–DUI is per se grave or serious. Strock had treated it as per se grave or serious, while the division below in Kennedy rejected that approach. The Supreme Court confronted and resolved this split in Kennedy.

IV. The Majority Opinion: Mens Rea, Strict Liability, and Proportionality

A. Why Vehicular Homicide–DUI Is Not Per Se Grave or Serious

The majority approaches the per se question in three principal steps.

1. Mens rea as a “key gauge of culpability”

Justice Hood begins with the statutory elements of vehicular homicide–DUI:

1. Operating or driving a motor vehicle;
2. While under the influence of alcohol or one or more drugs; and

3. Such conduct is the proximate cause of the death of another.

The statute explicitly defines this as a strict‑liability crime. It requires no proof that the defendant acted intentionally, knowingly, recklessly, or even with criminal negligence regarding the death. By contrast, Solem and Colorado’s proportionality cases treat the offender’s mental state as central to assessing moral blameworthiness.

Because vehicular homicide–DUI lacks any mens rea element, the majority reasons that courts cannot reliably say that every conviction under the statute reflects the same degree of culpability across all factual scenarios. In other words, there may be marginal cases—however rare—where:

• The driver’s impairment is barely over the legal threshold,
• The driving conduct is otherwise unremarkable, and
• The fatality results from an unusual chain of events.

In such cases, culpability might be substantially lower than in the paradigmatic, highly reckless drunk‑driving homicide. Because the per se designation requires that the offense be grave or serious in every potential factual scenario, the absence of a mens rea element undermines the doctrinal foundation for such a label.

2. Strict‑liability offenses and the per se doctrine

The majority then draws a categorical line: Colorado has never designated a strict‑liability offense as per se grave or serious, and the court declines to do so now. This is not an idle observation but a structural one:

• Per se status is conceptually analogous to a facial constitutional rule (citing United States v. Salerno, 481 U.S. 739, 745 (1987)): to label a statute per se grave or serious is to say there is “no set of circumstances” under which the offense, as statutorily defined, would yield conduct that is not grave or serious.
• Strict‑liability statutes, by their nature, decouple criminal liability from any mental‑state element. That decoupling makes it especially difficult to say that all conduct swept in by the statute is equally grave or serious for proportionality purposes.

In essence, the court says: where the legislature has declined to specify a mental state, courts should be hesitant to read in uniformly high culpability for all offenders when performing constitutional proportionality review.

3. Harm, standing alone, is not enough

Justice Hood explicitly acknowledges that vehicular homicide–DUI always involves the ultimate harm—the death of a human being. The court is careful not to trivialize this:

• The harm is “enormous.”
• The offense is plainly serious in everyday speech and in sentencing policy.

But the court emphasizes that harm alone does not justify a per se designation. Several other homicide‑type offenses—manslaughter, criminally negligent homicide, careless driving resulting in death—also always involve death, but none has been deemed per se grave or serious. The distinctive feature of the per se doctrine is not merely severe harm, but a combination of severe harm and consistently high culpability across all factual permutations.

Accordingly, the majority holds that vehicular homicide–DUI cannot be treated as per se grave or serious under Colorado’s proportionality jurisprudence, and it formally disapproves inconsistent court of appeals decisions such as Strock.

B. Kennedy’s Sentence and the Abbreviated Proportionality Review

Having rejected the per se shortcut, the court proceeds to a case‑specific abbreviated proportionality review.

1. Gravity of Kennedy’s conduct

The majority’s gravity assessment emphasizes both harm and culpability as reflected in the facts (not merely the elements):

• Actual harm: One victim was killed; two others were severely injured; one suffered partial paralysis.
• Severity of intoxication: Hours after the crash, Kennedy’s BAC was 0.282, over three times the legal limit.
• Recidivism and failed rehabilitation:
  • This was Kennedy’s fourth drinking‑and‑driving offense.
  • She continued to abuse alcohol and medication even after being released on bond in this case.

These facts, the court concludes, demonstrate high culpability and grave harm, negating any suggestion that Kennedy’s vehicular homicide–DUI conviction was at the mild end of the spectrum.

2. Harshness of the penalty

The court then examines the harshness of the twenty‑four‑year sentence for vehicular homicide–DUI:

• The sentence is within the statutorily authorized aggravated range for the offense.
• Sentences within the statutory range are presumed constitutional; legislative judgment on punishment is entitled to deference.
• Kennedy affirmatively agreed, as part of a negotiated plea, to a sentencing range of eight to thirty‑three years that encompassed the twenty‑four years actually imposed.
• The sentence includes the possibility of parole, which mitigates harshness in the proportionality analysis.

Considering gravity and harshness together, the majority finds no inference of gross disproportionality. Because this threshold inference is absent, Kennedy is not entitled to an extended proportionality review comparing sentences across crimes and jurisdictions.

V. The Concurring Opinions: Competing Views of Per Se Gravity

A. Justice Boatright (joined by Chief Justice Márquez): Vehicular Homicide–DUI Is Per Se Grave or Serious

Justice Boatright agrees that Kennedy’s sentence is constitutional, but he “see[s] it completely the opposite” regarding the per se question.

1. Voluntariness as culpability in strict liability

For Justice Boatright, the central moral fact is that in every vehicular homicide–DUI:

• The defendant voluntarily chooses to become intoxicated, and
• Then voluntarily drives a motor vehicle.

Citing Rostad, he emphasizes that strict liability in Colorado still requires a voluntary act—the minimal “conscious mental activity” sufficient for criminal liability. Thus, he rejects the majority’s suggestion that strict liability leaves courts unable to assess culpability:

• The legislature has chosen to define culpability for vehicular homicide–DUI in terms of voluntary conduct (drinking and driving), not in terms of the offender’s mental state regarding the resulting death.
• Every conviction for vehicular homicide–DUI, by statutory definition, reflects this baseline culpable choice.

2. Magnitude of harm and “specific evil”

Justice Boatright underscores the extraordinary harm of drunk‑driving fatalities, citing National Highway Traffic Safety Administration data:

• Thirty‑four people die every day in the U.S. due to drunk driving—one every forty‑two minutes.
• Annual alcohol‑related highway fatalities remain high—over 12,000 deaths in recent years.

He quotes U.S. Supreme Court references to the “carnage” and “slaughter” on the highways, and he invokes this court’s own acknowledgment in Hulse that vehicular homicide addresses a “specific evil” of great societal consequence. In his view:

• Vehicular homicide–DUI always involves completed death (never just an attempt).
• It is a standalone offense, not a lesser‑included form of something else.
• The “absolute magnitude” of the crime—senseless loss of life—makes it grave in every case.

3. Legislative signals vs. Wells‑Yates

Responding to Wells‑Yates, which used recent legislative reductions in drug penalties as a reason against per se gravity for drug offenses, Justice Boatright notes that:

• In the DUI context, the legislative trend is the opposite: penalties have increased and BAC thresholds have been tightened over decades.
• Colorado has not softened penalties for vehicular homicide–DUI; it has, for example, created felony DUI for fourth convictions.

Given this backdrop, he sees no legislative basis for treating vehicular homicide–DUI as anything other than inherently grave and serious.

4. Conclusion of the concurrence

Justice Boatright would hold that vehicular homicide–DUI is per se grave or serious. In his view:

• The offense always entails culpable voluntary conduct and catastrophic harm.
• It neatly fits the “rare” category of crimes that are grave or serious in every potential factual scenario.

He therefore concurs only in the judgment, not in the majority’s doctrinal holding on per se status.

B. Justice Samour (joined by Justice Gabriel): Questioning the Per Se Doctrine Itself

Justice Samour fully joins the majority, including its refusal to classify vehicular homicide–DUI as per se grave or serious. But his special concurrence is devoted to a broader institutional question: Should Colorado retain the per se doctrine at all?

1. The per se label as a Colorado outlier

Justice Samour stresses that the per se grave or serious concept:

• Has no basis in U.S. Supreme Court Eighth Amendment jurisprudence.
• Is unique to Colorado and was developed in a line of state decisions (e.g., Gaskins, Close, Deroulet).
• Is in tension with the identical wording of the Eighth Amendment and article II, § 20, and with Colorado’s general practice of following the Supreme Court’s proportionality framework.

2. Due process and fairness concerns

The core of his critique is that per se designations:

• Allow courts to skip the gravity assessment in abbreviated proportionality review.
• Combine that shortcut with strong deference to legislative sentencing ranges, thus making statutorily authorized sentences almost immune to proportionality challenges.
• Are especially troubling in habitual‑criminal settings, where trial courts have no discretion once predicate felonies are established.

He quotes Wells‑Yates’s warning that per se labels can leave sentences “impervious to attack on proportionality grounds,” a result he finds inconsistent with the constitutional guarantee against cruel and unusual punishment.

3. Limited benefits, significant costs

Justice Samour is skeptical that the per se doctrine delivers meaningful gains:

• While the gravity determination is “imprecise” and somewhat “art” rather than science, the Solem/McDonald factors provide adequate guidance.
• In practice, applying these factors to a particular case is neither exceptionally burdensome nor time‑consuming, as the majority’s brief gravity analysis in Kennedy illustrates.
• By contrast, debates over per se status (as in this very case) can be extensive, divisive, and conceptually confusing.

He notes that the drug‑offense experience in Wells‑Yates revealed another problem: per se labels can ossify even as legislative policy evolves. If the legislature later reduces penalties or reclassifies crimes, per se labels may lag behind, preserving an inflated sense of gravity inconsistent with current policy.

4. Invitation for future reconsideration

Because the question of abolishing the per se doctrine was not fully briefed, Justice Samour does not propose resolving it in Kennedy. Instead, he:

• Signals that the doctrine’s foundations are weak and that its disadvantages likely outweigh its benefits.
• Emphasizes that eliminating per se designations would be a procedural change in how courts conduct abbreviated proportionality review, not a retroactive invalidation of sentences (citing McDonald).

Taken together, his concurrence suggests that Kennedy may be a transitional case, presaging a future decision that could remove the per se category from Colorado’s proportionality jurisprudence altogether.

VI. Precedents and Their Influence in Kennedy

A. Federal Cases

• Solem v. Helm, 463 U.S. 277 (1983)
  Provides the two‑step proportionality framework and the criteria for assessing gravity (harm and culpability). McDonald and the majority in Kennedy draw heavily from Solem’s factors.
• Harmelin v. Michigan, 501 U.S. 957 (1991)
  Confirms that the controlling test is whether the sentence is “grossly disproportionate.” The majority in Kennedy cites Harmelin’s articulation of the standard.
• United States v. Salerno, 481 U.S. 739 (1987)
  Supplies the “no set of circumstances” language, which the majority uses by analogy to explain what it means for a crime to qualify as per se grave or serious based on its elements.
• Birchfield v. North Dakota, 579 U.S. 438 (2016); Mitchell v. Wisconsin, 588 U.S. 840 (2019); South Dakota v. Neville, 459 U.S. 553 (1983); Tate v. Short, 401 U.S. 395 (1971)
  Cited mainly in Justice Boatright’s concurrence to highlight the national recognition of the severe harms of drunk driving and the effectiveness of stringent DUI laws.

B. Colorado Proportionality and Per Se Cases

• Close v. People, 48 P.3d 528 (Colo. 2002) (abrogated in part by Wells‑Yates)
  Earlier articulation of abbreviated and extended proportionality review; recognized the heavy deference due to legislative sentencing ranges.
• People v. Gaskins, 825 P.2d 30 (Colo. 1992)
  Part of the early line of cases designating some offenses as per se grave or serious based on their inherent violence or potential for violence or drug‑related harm.
• Deroulet v. People, 48 P.3d 520 (Colo. 2002) (abrogated in part by Wells‑Yates)
  Another pre‑Wells‑Yates case that accepted and extended per se classifications.
• Rutter v. People, 2015 CO 71
  Emphasizes that statutorily authorized sentences are presumed constitutional and that sentences within the presumptive range rarely raise an inference of gross disproportionality.
• Wells‑Yates v. People, 2019 CO 90M
  The centerpiece for the majority’s analysis:
  • Introduces a more rigorous test for per se status: limited to “rare” offenses that necessarily involve grave or serious conduct in every case.
  • Removes narcotics‑related offenses from blanket per se status, in part due to legislative reductions in penalties.
  • Warns that per se designations should be used sparingly because of their due process consequences.
• McDonald v. People, 2024 CO 75
  Reaffirms and systematizes the Solem/Wells‑Yates factors; lists which crimes remain per se grave or serious; holds Wells‑Yates’s rules about per se designations apply retroactively in proportionality reviews.

C. Vehicular Homicide and DUI‑Related Cases

• People v. Hulse, 557 P.2d 1205 (Colo. 1976)
  Cited in Justice Boatright’s concurrence to support strong legislative deference for heightened penalties addressing vehicular homicide as a “specific evil.”
• People v. Rostad, 669 P.2d 126 (Colo. 1983)
  Clarifies that strict‑liability vehicular homicide–DUI still requires a voluntary act and thus entails a minimal level of “conscious mental activity.” Central to Justice Boatright’s argument that vehicular homicide–DUI has sufficient culpability to be per se grave or serious.
• People v. Strock, 252 P.3d 1148 (Colo. App. 2010)
  Had previously designated vehicular homicide–DUI (or treated it) as per se grave or serious. Explicitly disapproved by the majority in Kennedy.

VII. Impact and Future Implications

A. Immediate Doctrinal Impact

1. Vehicular homicide–DUI is definitively not per se grave or serious.
   Trial and appellate courts in Colorado can no longer simply assume the gravity of vehicular homicide–DUI based on its elements alone. In every proportionality challenge involving this offense, courts must:
   • Evaluate gravity case by case, using the Solem/McDonald factors, and
   • Compare that gravity to the actual sentence imposed.
2. Strict‑liability offenses are unlikely candidates for per se status.
   The majority’s categorical observation—that Colorado has never designated a strict‑liability offense as per se grave or serious and declines to start now—strongly suggests that:
   • No strict‑liability crime should be treated as per se grave or serious going forward, absent extraordinary circumstances.

B. Practical Consequences for Vehicular Homicide–DUI Sentencing

For defendants convicted of vehicular homicide–DUI, Kennedy:

• Opens the door to proportionality challenges that would have been foreclosed under a per se designation.
• Nonetheless sets a high bar for such challenges:
  • Where the offense involves high BAC, prior DUIs, egregious driving, or additional injuries, courts are likely to find no inference of gross disproportionality for statutorily authorized sentences.
  • Plea agreements that encompass the challenged term will weigh heavily against the defendant, as in Kennedy.

At the same time, Kennedy suggests that in truly marginal cases—e.g., minimal criminal history, near‑threshold impairment, unusual contributing circumstances—defendants may now have a more viable argument for extended proportionality review than they would have had if the offense were per se grave or serious.

C. Habitual Criminal Sentencing

The per se label matters most when courts review habitual criminal sentences, which can be dramatically enhanced. Removing vehicular homicide–DUI from the per se category has at least two implications:

• Defendants facing habitual enhancements based on vehicular homicide–DUI will receive a more nuanced gravity assessment rather than an automatic presumption of extreme seriousness.
• The combined effect of Wells‑Yates, McDonald, and Kennedy is to modestly expand the scope of meaningful proportionality review in habitual cases, though the gross‑disproportionality standard remains stringent.

D. The Future of the Per Se Doctrine

Justice Samour’s concurrence positions Kennedy as a potential pivot point in Colorado’s proportionality jurisprudence:

• Two justices (Samour and Gabriel) openly suggest that the per se category should be eliminated.
• The majority opinion itself, though not abandoning the doctrine, reflects skepticism by:
  • Reinforcing that per se status must be “rare,” and
  • Refusing to expand the list to include vehicular homicide–DUI.

Future litigants may well seek certiorari squarely on whether the per se doctrine should survive at all. If the court ultimately “deep‑sixes” the doctrine, as Justice Samour suggests, Colorado would fully align its proportionality analysis with Solem and U.S. Supreme Court precedent, and every proportionality challenge would require at least a minimal gravity‑and‑harshness analysis tailored to the case.

VIII. Complex Concepts Simplified

A. “Gross Disproportionality”

A sentence is unconstitutional only if it is not just harsh, but grossly disproportional to the offense. That means:

• The punishment is so extreme relative to the crime that it shocks the conscience or runs counter to contemporary standards of decency.
• Most long sentences within statutory ranges—even for serious conduct—will not meet this standard.

B. Abbreviated vs. Extended Proportionality Review

• Abbreviated review: A quick, threshold comparison:
  • How serious was the actual conduct?
  • How severe is the actual sentence?
  If no reasonable inference of gross disproportionality arises, the analysis ends.
• Extended review: A deeper dive that includes comparing:
  • Sentences for other crimes within Colorado, and
  • Sentences for the same crime in other states.
  Courts reach this step only if the abbreviated review indicates a potential gross disproportionality.

C. “Per Se Grave or Serious” Offense

A “per se grave or serious” offense is one that courts have decided is inherently very serious in every case, based on its statutory elements alone. For such offenses:

• Courts assume the gravity of the offense without looking at the particular facts.
• They skip directly to considering whether the sentence is harsh.

This makes it substantially harder for a defendant to succeed on a proportionality challenge.

D. Strict Liability vs. Mens Rea

• Mens rea: The mental state required for a crime—intentional, knowing, reckless, criminally negligent. It reflects how blameworthy the defendant is.
• Strict liability: The statute does not require proof of any of these mental states. The prosecution need only prove:
  • A voluntary act (or omission), and
  • The other elements (e.g., being under the influence, causing death).

In Colorado, strict‑liability crimes still require voluntary conduct but dispense with proof of a conventional mental state regarding the harmful result. That is why the majority in Kennedy views them as poor candidates for per se gravity: culpability can vary widely from case to case even though the statutory elements are the same.

E. Aggravated Sentencing Range and Parole

• Aggravated range: Colorado statutes often provide a presumptive sentencing range and an aggravated range. Sentences in the aggravated range (like Kennedy’s twenty‑four years) reflect judicial findings of aggravating circumstances, but they remain within the outer bounds authorized by statute.
• Parole: Most term‑of‑years sentences allow for the possibility of release before the full term is served. In proportionality analysis, this possibility reduces the effective harshness of the punishment.

IX. Conclusion

People v. Kennedy is a significant development in Colorado’s proportionality jurisprudence. It does three important things:

1. It holds that vehicular homicide–DUI is not per se grave or serious, primarily because it is a strict‑liability offense lacking a mens rea element—a key marker of culpability.
2. It reaffirms that statutorily authorized sentences, especially those embraced in plea agreements, are presumptively constitutional and that the threshold for finding gross disproportionality is high. Kennedy’s twenty‑four‑year sentence, imposed in the aggravated range for a recidivist offender whose conduct caused death and severe injury, does not meet that threshold.
3. Through the concurring opinions, it exposes deep fissures in the court’s view of the per se grave or serious doctrine—one concurrence would expand it to vehicular homicide–DUI, and another would abolish it altogether.

In the broader legal context, Kennedy continues the recalibration begun in Wells‑Yates and McDonald, moving Colorado away from rigid categorical presumptions and toward more nuanced, fact‑sensitive proportionality reviews. While the decision does not weaken the state’s substantive commitment to punishing drunk‑driving homicides severely, it ensures that constitutional proportionality analysis retains a meaningful, individualized component—even in the face of grave harm and strong legislative policies against DUI.