A New York jury recently acquitted Guy Rivera of first-degree murder in the 2024 shooting death of NYPD Detective Jonathan Diller during a traffic stop in Queens. Rivera was convicted of manslaughter and weapons charges instead. He faces up to 90 years in prison.
When that verdict was reported, the reaction in many corners was confusion. Acquitted of murder but facing 90 years? How does that work?
The answer lies in something most people outside the criminal justice system rarely think about: the mental state element of a criminal charge. In homicide cases, the difference between murder and manslaughter is not about what happened. It is about what was going on in the defendant’s mind when it happened. Understanding that distinction is one of the most important things a jury does in any homicide case and it is the distinction that will define Rivera’s sentence, whatever it turns out to be.
Mental State Is the Architecture of Criminal Law
Every serious criminal offense in Texas (and in virtually every American jurisdiction) has two components: the act itself, and the mental state with which it was committed. The Latin term is mens rea, meaning guilty mind. The act without the mental state is not a crime. The mental state without the act is not a crime. The criminal charge is the combination.
Texas Penal Code §6.02 defines four mental states, listed here from most to least culpable:
Intentional: The person consciously desires to cause the result. They want the outcome to occur.
Knowing: The person is aware that their conduct is reasonably certain to cause the result, even if causing that specific result is not their conscious objective.
Reckless: The person is aware of a substantial and unjustifiable risk that the result will occur, and disregards that risk in a way that constitutes a gross deviation from the standard of care a reasonable person would exercise.
Criminally negligent: The person should have been aware of a substantial and unjustifiable risk, but was not and that failure to perceive the risk is a gross deviation from the standard of care.
The homicide charges are built on these distinctions. In Texas, murder requires intentional or knowing conduct. Manslaughter requires reckless conduct. Criminally negligent homicide requires criminal negligence. Same dead person, potentially four different charges depending entirely on what the state can prove about what was in the defendant’s mind.
What This Means in Practice: The Rivera Verdict
The Rivera jury was presented with the same set of facts and asked to determine which mental state applied. First-degree murder in New York requires intent to cause death (the deliberate, conscious desire to kill). The jury found the state had not proven that beyond a reasonable doubt.
Manslaughter, by contrast, can be established with a lesser showing about mental state (reckless conduct, or conduct that is so dangerous that it demonstrates depraved indifference to human life, depending on the specific charge). The jury found that standard met.
Rivera was not acquitted because the jury thought the shooting was justified or that the detective’s death was acceptable. He was acquitted of first-degree murder because the jury was not convinced, beyond a reasonable doubt, that he formed the specific intent required for that charge. The manslaughter conviction reflects a different legal conclusion about his mental state and not a different conclusion about what he did.
The sentencing consequences remain severe. Manslaughter is a serious felony. The weapons charges stack on top. The headline “acquitted of murder” describes a legal verdict on a specific mental state element, not an exoneration.
How This Plays Out in Texas Homicide Cases
Texas uses the same mental state framework. The Texas Penal Code defines its homicide offenses as follows:
Capital murder (§19.03): Intentional murder with at least one aggravating circumstance — the victim was a peace officer killed in the line of duty, the murder occurred during another felony, the defendant was hired to commit the killing, or several other enumerated circumstances. Punishment is death or life without parole.
Murder (§19.02): Intentionally or knowingly causes the death of another person. Also covers intentional serious bodily injury that results in death, or committing or attempting to commit a felony other than manslaughter in a way that results in death (felony murder). Punishment is generally a first-degree felony: 5 to 99 years or life.
Manslaughter (§19.04): Recklessly causes the death of another person. A second-degree felony: 2 to 20 years. The same punishment range as intoxication manslaughter, which is the form of manslaughter most frequently litigated in my practice.
Criminally negligent homicide (§19.05): Causes the death of another person through criminal negligence. A state jail felony: 180 days to 2 years.
The difference between a life sentence and a two-year sentence in a case where someone died is, in Texas law, entirely a function of what the jury concludes about the defendant’s mental state.
Why Juries Struggle with Mental State
Mental state is the hardest element for a jury to evaluate because it requires them to look inside a person’s mind at a specific moment in the past — a moment that was almost certainly chaotic, fast-moving, and emotionally charged. No one can directly observe intent. The jury has to infer it from circumstantial evidence: what the defendant said, what they did before and after, how they behaved, what their prior conduct showed.
This inferential process is where skilled defense work happens. The prosecution presents a narrative about what the defendant was thinking. The defense presents an alternative narrative. The jury decides which is more consistent with the evidence beyond a reasonable doubt.
In intoxication manslaughter cases (the category most relevant to this firm’s practice) the mental state question often centers on recklessness: was the defendant aware of a substantial and unjustifiable risk that their conduct would cause death? Driving while intoxicated is legally sufficient to establish that awareness in most cases. But the causation question (whether the defendant’s conduct, and specifically their intoxicated state, actually caused the death) is a separate question that requires independent analysis.
The Instruction That Changes Everything: Sudden Passion
Texas law provides one more mental state wrinkle that is worth understanding: the sudden passion doctrine. Under Texas Penal Code §19.02(d), a defendant convicted of murder may raise sudden passion (passion directly caused by and arising out of provocation by the victim, so great that a person of ordinary temper could not master it) during the punishment phase. If the jury finds sudden passion by a preponderance of the evidence, the punishment range drops from a first-degree felony to a second-degree felony.
This means that a jury can find a defendant guilty of murder but then, in the punishment phase, reduce the effective sentencing range by more than half based on a finding about the defendant’s emotional state at the moment of the killing. The mental state question does not end at the guilt-innocence verdict. It continues into punishment.
The Rivera verdict is a vivid example of why the specific charge matters. The legal distinction between murder and manslaughter is not a technicality. It is the difference between the jury concluding that a person chose to kill and concluding that they acted with reckless disregard for human life. Both conclusions can result in severe punishment. Both reflect a serious moral judgment about the defendant’s conduct. But they are not the same judgment, and the law treats them differently for a reason.
Deandra Grant Law brings more than 30 years of criminal defense experience and more than 500 trials to every case. Partner Douglas Huff leads our violent crimes defense practice.