this should explain and clarify
http://dictionary.law.com
manslaughter
n. the unlawful killing of another person without premeditation or so-called "malice aforethought" (an evil intent prior to the killing). It is distinguished from murder (which brings greater penalties) by lack of any prior intention to kill anyone or create a deadly situation. There are two levels of manslaughter: voluntary and involuntary. Voluntary manslaughter includes killing in heat of passion or while committing a felony. Involuntary manslaughter occurs when a death is caused by a violation of a non-felony, such as reckless driving (called "vehicular manslaughter"). Examples: Eddy Hothead gets into a drunken argument in a saloon with his acquaintance Bob Bonehead, and Hothead hits Bonehead over the head with a beer bottle, causing internal bleeding and death. Brent Burgle sneaks into a warehouse intent on theft and is surprised by a security man, whom Burgle knocks down a flight of stairs, killing him. Both are voluntary manslaughter. However, if either man had used a gun, a murder charge is most likely since he brought a deadly weapon to use in the crime. The immediate rage in finding a loved one in bed with another followed by a killing before the passion cools usually limits the charge to voluntary manslaughter and not murder, but prior attacks could convince a District Attorney and a jury that the killing was not totally spontaneous. Lenny Leadfoot drives 70 miles per hour on a twisting mountain road, goes off a cliff and his passenger is killed in the crash. Leadfoot can be charged with involuntary manslaughter.
murder
n. the killing of a human being by a sane person, with intent, malice aforethought (prior intention to kill the particular victim or anyone who gets in the way) and with no legal excuse or authority. In those clear circumstances, this is first degree murder. By statute, many states consider a killing in which there is torture, movement of the person before the killing (kidnapping) or the death of a police officer or prison guard, or it was as an incident to another crime (as during a hold-up or rape), to be first degree murder, with or without premeditation and with malice presumed. Second degree murder is such a killing without premeditation, as in the heat of passion or in a sudden quarrel or fight. Malice in second degree murder may be implied from a death due to the reckless lack of concern for the life of others (such as firing a gun into a crowd or bashing someone with any deadly weapon). Depending on the circumstances and state laws, murder in the first or second degree may be chargeable to a person who did not actually kill, but was involved in a crime with a partner who actually did the killing or someone died as the result of the crime. Example: In a liquor store stick-up in which the clerk shoots back at the hold-up man and kills a bystander, the armed robber can be convicted of at least second degree murder. A charge of murder requires that the victim must die within a year of the attack. Death of an unborn child who is "quick" (fetus is moving) can be murder, provided there was premeditation, malice and no legal authority. Thus, abortion is not murder under the law. Example: Jack Violent shoots his pregnant girlfriend, killing the fetus. Manslaughter, both voluntary and involuntary, lacks the element of malice aforethought.
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