query: Who is Dexter's sister?
passage: Jennifer Carpenter
Jennifer Leann Carpenter (born December 7, 1979) is an American actress. She is known for playing Debra Morgan, the adoptive sister of the title character of the Showtime series Dexter, for which she earned a Saturn Award in 2009, and also for playing Rebecca Harris in the CBS television series Limitless.
passage: Darkly Dreaming Dexter
Dexter succeeds in managing his double life until he investigates the "Tamiami Slasher", who has murdered three prostitutes. Dexter's adoptive sister, Deborah, who is also on the force and wants to be promoted to Homicide — and knowing that her brother has eerie "hunches" — asks him for help in solving the case. Dexter eventually decides to help Deborah due to his moral code, but still feels a compelling pull to the killer due to similar desires. After a lucid dream, Dexter drives around Miami and spots a refrigerated truck. When he follows the truck, the killer throws a severed head at his car.