On The Mysteries of Laura episode “The Mystery of the Unknown Caller,” Laura’s (Debra Messing) younger sister Lucy shows up in town. The reunion isn’t planned or really welcomed. Lucy is a suspect in a murder investigation in Brooklyn. After Laura runs after and tackles her sister, the two reheads sit down for a chat. “You’re so good at this policing thing,” the younger one says with sarcasm. Nonetheless, Laura pledges to save her sister (with a pinky swear!).
Lucy Diamond is portrayed by Debby Ryan. The 22-year-old actress is best known for her roles on Disney Channel’s Jessie (Jessie Prescott, the young nanny living in New York City) and The Suite Life On Deck
