Second Degree Murder

Second-Degree Murder: "all other murders"—any murder that is not first-degree.

Typical Categories

Intent-to-kill without premeditation and deliberation.
Intent to do serious bodily injury (death results).
Depraved heart / extreme recklessness — ∆ consciously disregarded a substantial risk to human life under circumstances manifesting extreme indifference (this is more than ordinary recklessness).

Distinguished from Other Offenses

vs. First-Degree Murder: lacks the premeditation/deliberation that elevates to first degree.
vs. Voluntary Manslaughter: lacks the heat-of-passion / adequate provocation mitigation.
vs. Involuntary Manslaughter: requires extreme recklessness (depraved heart), not mere recklessness or criminal negligence.

Depraved-Heart vs. Involuntary Manslaughter

Depraved heart: "I know this could kill someone—and I don't care." → second-degree murder.
Recklessness: "I know there's a risk, but I underestimate it." → manslaughter (MPC) or sometimes IM.
Criminal negligence: "I didn't realize the risk, but I should have." → involuntary manslaughter.