In United States law, depraved-heart murder, also known as depraved-indifference murder, is a type of murder where an individual acts with a "depraved indifference" to human life and where such act results in a death, despite that individual not explicitly intending to kill. In a depraved-heart murder, defendants commit an act even though they know their act runs an unusually high risk of causing death or serious bodily harm to a person. If the risk of death or bodily harm is great enough, ignoring it demonstrates a "depraved indifference" to human life and the resulting death is considered to have been committed with malice aforethought. In some states, depraved-heart killings constitute second-degree murder, while in others, the act would be charged with "wanton murder," varying degrees of manslaughter, or third-degree murder.
It ["depraved heart" murder] is the form [of murder] that establishes that the wilful doing of a dangerous and reckless act with wanton indifference to the consequences and perils involved is just as blameworthy, and just as worthy of punishment, when the harmful result ensues as is the express intent to kill itself. This highly blameworthy state of mind is not one of mere negligence... It is not merely one even of gross criminal negligence... It involves rather the deliberate perpetration of a knowingly dangerous act with reckless and wanton unconcern and indifference as to whether anyone is harmed or not. The common law treats such a state of mind as just as blameworthy, just as anti-social and, therefore, just as truly murderous as the specific intents to kill and to harm.
The common law punishes unintentional homicide as murder if the defendant commits an act of gross recklessness. A classic example of depraved-heart murder under the common law is in the case Commonwealth v. Malone, a Pennsylvania case in which the court affirmed the second-degree murder conviction of a teenager for a death arising from a game of modified Russian roulette in which each player pointed and fired the gun at the other, eventually resulting in the death of one of them.
Depraved-heart murder is recognized in the Model Penal Code § 210.2(1)(b). The Model Penal Code considers unintentional killing to constitute murder when the conduct of the defendant manifests "extreme indifference to the value of human life".
The Canadian Criminal Code categorises murder as first- and second-degree for sentencing purposes. However, the Supreme Court held that murder requires, at minimum, subjective knowledge that death is a likely consequence of the defendant's actions. Mere recklessness, no matter how extreme, is not sufficient to burden the defendant with the stigma of being labeled a murderer. The circumstances that give rise to depraved-heart second-degree murder in the US only constitute manslaughter in Canada.
Murder is not classified into degrees, unlike in Canada, but sentences are more severe in cases where there are more aggravating than mitigating factors. The guidelines start with the recommended sentence for murder being 12 years if the offender is under 18 (see Starting points for murder). An offender 18 years of age or older, will receive a minimum non-parole period of 15 years. Penalties increase when at least one aggravating factor (as defined in the Criminal Justice Act) can be proven beyond a reasonable doubt. In cases involving multiple murders, a second (multiple) murder conviction(s), or the murder of a police officer, then the detention term can be the prisoner's whole life. In English criminal law, however, murder requires intent to kill or cause grievous bodily harm. Recklessness as to harm will not suffice. In a case where death results from recklessness, the defendant will be guilty of reckless manslaughter.
A similar concept is Eventualvorsatz, also called dolus eventualis or bedingter Vorsatz (literally: "conditional intent"). Under this concept, a court can treat the result of a criminal act as intentional if the defendant did not explicitly intend this result, but realized it was likely and knowingly accepted this risk.
While Eventualvorsatz can apply to any crime, it is usually only applied in cases involving bodily harm or murder. Typical cases where courts recognized Eventualvorsatz (in this case for murder) include setting fire to an inhabited house and reckless speeding in an urban area. 
In the 1946 case, Commonwealth v. Malone, the Supreme Court of Pennsylvania affirmed the conviction of a teenager on the charge of second degree murder using the depraved-heart doctrine. The teenager in question had set up a game of Russian roulette which ended in the death of another teenager, a friend of the defendant. When tried for the crime of murder, his defense argued that since he had no intent to kill, the defendant could not be convicted of murder. The prosecution successfully argued using the depraved-heart doctrine that his recklessness and carelessness amounted to a level of negligence sufficient to serve as evidence of criminally culpable intent.