Difference between manslaughter and murder.
Manslaughter is a legal term for the killing of a human being, in a manner considered by law as less culpable than murder. The distinction between murder and manslaughter is said to have first been made by the Ancient Athenian lawmaker Dracon in the 7th century BC.
The law generally differentiates between levels of criminal culpability based on the mens rea, or state of mind. This is particularly true within the law of homicide, where murder requires either the intent to kill – a state of mind called malice, or malice aforethought – or the knowledge that one's actions are likely to result in death; manslaughter, on the other hand, requires a lack of any prior intention to kill or create a deadly situation.
Manslaughter is usually broken down into two distinct categories: voluntary manslaughter and involuntary manslaughter.
As to the first, if they thought it likely that deceased or any other person had taken out the Duke of Denver's revolver that night for any purpose, and that, in looking at, cleaning, shooting with, or otherwise handling the weapon, it had gone off and killed deceased accidentally, then they would return a verdict of death by misadventure accordingly. In that case, how did they explain the conduct of the person, whoever it was, who had dragged the body to the door?
The Coroner then passed on to speak of the law concerning manslaughter. He reminded them that no mere words, however insulting or threatening, can be an efficient excuse for killing anybody, and that the conflict must be sudden and unpremeditated. Did they think, for example, that the Duke had gone out, wishing to induce his guest to return and sleep in the house, and that deceased had retorted upon him with blows or menaces of assault?
If so, and the Duke, having a weapon in his hand, had shot deceased in self-defense, that was only manslaughter. But, in that case, they must ask themselves how the Duke came to go out to deceased with a lethal weapon in his hand? And this suggestion was in direct conflict with the Duke's own evidence.
Lastly, they must consider whether there was sufficient evidence of malice to justify a verdict of murder. They must consider whether any person had a motive, means, and opportunity for killing deceased; and whether they could reasonably account for that person's conduct on any other hypothesis. And, if they thought there was such a person, and that his conduct was in any way suspicious or secretive, or that he had willfully suppressed evidence which might have had a bearing on the case, or (here the Coroner spoke with great emphasis, staring over the Duke's head) fabricated other evidence with intent to mislead—then all these circumstances might be sufficient to amount to a violent presumption of guilt against some party, in which case they were in duty bound to bring in a verdict of willful murder against that party.
And, in considering this aspect of the question, the Coroner added, they would have to decide in their own minds whether the person who had dragged deceased towards the conservatory door had done so with the object of obtaining assistance or of thrusting the body down the garden well, which, as they had heard from Inspector Craikes, was situated close by the spot where the body had been found. If the jury were satisfied that deceased had been murdered, but were not prepared to accuse any particular person on the evidence, they might bring in a verdict of murder against an unknown person, or persons; but, if they felt justified in laying the killing at any person's door, then they must allow no respect of persons to prevent them from doing their duty.
Guided by these extremely plain hints, the jury, without very long consultation, returned a verdict of willful murder against Gerald, Duke of Denver.