Abigail "Abby" Sciuto (pronounced "shoo-toe") is a fictional forensic scientist in the NCIS television series by CBS Television. The character is a goth with skills in tradional forensics, and in computer forensics and hacking. She is portrayed by Pauley Perrette.
Abby has a gothic style of dress, including black dresses and t-shirts, mini-skirts, and goth jewelery, including anklets and toe rings. She wears pigtailed dyed hair, and at least nine tattoos on her neck, arms, back, ankle and other places. While some of the tattoos are Perrette's, and real, others, such as the large cross on her back, are makeup applied for the occasions when Perrette shows her bare back on camera. The spider web on her neck is not real either, as producer Donald Bellisario wanted the character to have a tattoo that would be visible (almost) all the time.
Abby is a hearing child born to deaf parents, and likes her music loud. Like Gibbs, Abby enjoys caffeine, in the form of a fictional drink called "Caf-Pow," a coffee based beverage. When changing the artwork in her lab, she states that she has a "Chagall feeling", a reference to Marc Chagall, a Jewish Belo-Russian artist whose main works came from fantasy and dreams. Her favorite term for something out of ordinary is "hinky". It is also shown that she enjoys attending concerts, such as the Plastic Death concert which resulted in her having trouble hearing and having to ask DiNozzo to help her ID some audio evidence. Abby has stated that she dreams of visiting the Galápagos Islands and Dollywood before she dies. , Abby graduated with full honors from LSU with a triple major in sociology, criminology and psychology. She earned her master's degree from Georgia State University in criminology and forensic science. Sciuto's interest in forensics came from living near a wrecking yard and being intrigued by the cause and effect of the wrecks. 
Pauley Perrette started studying for a Master's Degree in Criminology before going into the entertainment industry, and has toured the real NCIS offices to meet with the real forensic specialists..
Abby is well-versed in her field of study; she is rarely stumped by the puzzles which Gibbs' team present to her. She does all the work on the evidence herself. In season 3, when she is given an "assistant", Charles "Chip" Sterling, she revolts, but puts up with him. He turns out to be homicidal, and as a result, Abby is freed of him.
It has been shown that she has a younger brother.
Abby gets on well with all the rest of the team, particularly McGee and Tony, and is fond of Ducky who uses her full name, Abigail.
Like Ducky, she shows no fear of Gibbs. The kisses on the cheek and hugs they share are present in many episodes, and Gibbs brings her her favorite beverage, Caf-Pow, on many occasions. Gibbs also shows a tolerance for her idiosyncracies, and a protectiveness over Abby. Abby is the daughter of deaf parents, and occasionally communicates with Gibbs using sign language.
Abby was a close friend of former team mate Caitlin Todd (Kate), hanging out after work and even talking Kate into getting a tattoo. Abby was cold towards Ziva at first, as Ziva was linked with Ari, who killed Kate. Abby eventually came around and they are now friends.
She had a relationship with McGee which she stated that she would like to keep casual. Although the relationship ended late in season one, she has since exhibited jealousy over both the attention that McGee gives to and receives from other women.
Pauley Perrette (AKA Abby Sciuto)