Cassie was born in Beijing, China. She has black, shoulder-length hair. She has brown eyes, and normally wears a red coat over a brown shirt, she wears a grey skirt. Her traits are: admirable, wide-eyed and pleasant.
As of the release of the World Edition, the player may choose Cassie to join the investigation of each crime scene (in any World Edition case) and provide hint bonuses. She's available as a 4-hint partner. (Note that this feature is only available on the mobile version of the game.)