Yup, RU hit the nail on the head. Also, dress professionally! Take all of your piercings out except for a couple in your ear lobes. Cover up tattoos. For ladies, no cleavage on display, for men, pull your pants up and wear a belt! I saw so many people when I interviewed that didn't follow these basic rules, and while WesternU tends to be more lenient with that than other schools, there's no reason to take a chance. Not to mention you're applying for professional school, so it's in your best interests to appear professional.
Also, treat your interview like a conversation. Mine lasted twice as long as everyone else's in my group and I think that's because it wasn't so much question and answer as it was a conversation.