Actually manslaughter is unintended death, resulting from negligence or a preventable accident. Like if a truck flips cause the guy didn\'t want to change the bald tires (that he knew about), killing a bystander.
If you kill someone in a fit of passion, as opposed to a planed death, that\'s murder in the second degree. Like this case.
However, when people co-operate, and plea-bargain, you can often get a murder case sentenced as a manslaughter in the first degree case, which carries a far lesser sentence. In Canada, 12-25, with parole possible after 1/3rd of the sentence is over.