Second degree murder is an unlawful killing committed with malice but without the premeditation and deliberation that raise a killing to first degree murder. It sits between first degree murder, which is the most serious form, and manslaughter, which generally involves a killing without malice.
The exact definition depends on the jurisdiction. Some states use degrees of murder, others use different labels, and the federal system has its own rule. This guide explains the common elements, how the categories compare, and why the line between them matters at sentencing.
The Common Elements
Prosecutors must generally prove that the defendant unlawfully killed another human being and acted with malice aforethought. Malice does not require hatred or ill will in the everyday sense. In criminal law, malice means one of several mental states:
- Intent to kill. The defendant meant to cause death, but the killing was not premeditated.
- Intent to cause serious bodily injury. The defendant intended grave harm, and death resulted.
- Depraved-heart recklessness. The defendant acted with extreme disregard for human life, such as firing a gun into a crowd.
- Felony murder. A death occurring during certain dangerous felonies, in jurisdictions that use that rule.
If the defendant acted with malice but without the deliberate planning that defines first degree murder, the killing is often charged as second degree.
First Degree vs Second Degree vs Manslaughter
| Offense | Key mental state | Typical example |
|---|---|---|
| First degree murder | Willful, deliberate, premeditated intent to kill | A planned killing carried out after reflection |
| Second degree murder | Malice, but no premeditation and deliberation | An intentional killing in a sudden rage, or a killing during an act of extreme recklessness |
| Voluntary manslaughter | Intent to kill mitigated by provocation or heat of passion | A killing in the immediate aftermath of a serious provocation |
| Involuntary manslaughter | Criminal negligence or a lesser unlawful act | A death caused by reckless driving without intent to harm |
The dividing line between first and second degree is usually premeditation. A killing can be intentional and still be second degree if the defendant formed the intent in the moment rather than after deliberation. Manslaughter, by contrast, lacks malice; the killing is unlawful but the mental state is less culpable.
How States Define It
There is no single national definition of second degree murder. States organize homicide law differently, so the same facts can carry different labels depending on where they occur.
California uses a degrees framework. Penal Code section 187 defines murder as the unlawful killing of a human being with malice aforethought, and section 189 lists the categories that are first degree, including willful, deliberate, and premeditated killings. All other murder is second degree. New York uses its own structure, with second degree murder defined at Penal Law section 125.25 and first degree murder at section 125.27. Some states do not use degrees at all and instead separate murder from manslaughter by mental state.
Because the statutes differ, always check the homicide provisions of the state where the conduct occurred. The official state code is the controlling text.
Felony Murder
Under the felony murder rule, a death that happens during certain dangerous felonies can be charged as murder even without intent to kill. Whether that death is first or second degree depends on the jurisdiction and on which felony is involved. Many states list certain felonies, such as robbery or burglary, as supporting first degree felony murder, while others classify felony murder as second degree.
The rule is controversial and has been narrowed in several states through legislation and court decisions. Some states limit it to deaths caused directly by a defendant, and others have restricted which underlying felonies qualify. Because the rule varies so much, it is a frequent source of litigation.
The Federal Rule
Federal homicide law is set out at 18 U.S.C. section 1111. It defines murder as the unlawful killing of a human being with malice aforethought and classifies as first degree murder killings that are willful, deliberate, malicious, and premeditated, along with killings committed by poison, lying in wait, or in the perpetration of certain enumerated felonies. The statute states that any other murder is murder in the second degree. Federal courts also handle killings on federal land, in special maritime and territorial jurisdiction, and in other circumstances tied to federal authority.
Defenses
Common defenses to a second degree murder charge include self-defense or defense of others, accident or lack of intent, and the absence of malice. In some jurisdictions, a defendant may argue diminished capacity or intoxication to negate the specific mental state required, though the availability of these defenses varies widely. Insanity is a separate defense that focuses on the defendant's capacity to understand the wrongfulness of the act.
The prosecution bears the burden of proving every element beyond a reasonable doubt. If the evidence shows a killing but not malice, the result may be manslaughter rather than murder.
Sentencing
Penalties for second degree murder vary significantly by state and by the presence of aggravating factors. Sentences often include a long term of imprisonment, and in many jurisdictions a life sentence with the possibility of parole is available. Some states impose a fixed term of years, and some allow the death penalty only for first degree murder. The range is broad, so the sentencing statute of the convicting jurisdiction controls.
Charging and Plea Decisions
Prosecutors decide which homicide charge to file, and the choice between first and second degree murder often turns on the evidence of planning. Defense counsel may seek a reduction to manslaughter or negotiate a plea to a lesser offense. Because the difference in exposure can be enormous, the charging decision is usually the central battleground in a homicide case, and it can change as evidence develops.
Bottom Line
Second degree murder is an unlawful killing with malice but without premeditation and deliberation. The label matters because it carries different penalties and different proof requirements than first degree murder and manslaughter, and because states define it in their own way.
This guide is general information, not legal advice. Homicide definitions and sentences vary by state and by the facts, and a criminal defense attorney can advise you on a specific case.