Wessel Ebersohn’s eleventh rule of thriller writing
Your subsidiary characters must be clearly drawn. Their characters must fit the roles they have to play in the story. Many writers base their characters on real people they know. They select a person whom they feel will fit the part in the story, then write the character with that person in mind. Very often a disclaimer in the front of a book, telling you that all the characters are products of the writer’s imagination, has been included for just this reason. No one wants to be sued for a fictitious character.