What is a pre-meditated murder?

Premeditated Murder is Murder that you think about and plan before you commit the homicide. For example, a husband can have a Mistress, and the Wife may find out. She can act as if she does not know what is going on when her husband leaves for hours a day for "work", or she can plan a slow painful death for him and his mistress! this is Premeditated Murder. I love studying Psychology of the Human brain.