I think what Sauron is getting at is that you have to intend to kill someone for it to be murder… even if it is a spur of the moment thing. Doing something dumb (out of anger or perhaps drunk driving) the charge is usually involuntary manslaughter though if it can be proved that you knew you were risking the lives of others and took no precautions or changed your actions to prevent it (ie everytime you get drunk you always drive home and one day you drive home drunk and kill someone then you might have a case for a weak form of murder in that it was likely you were going to kill someone even if it was only yourself).