Anthony (Tony) DiNozzo
Anthony "Tony" DiNozzo comes from a wealthy family from New York. He is an only child but has been cut off from his family's fortune - similar to Michael Weatherly in real life.
He attended Rhode Island Military Academy as a teenager, and graduated from The Ohio State University, where he played basketball, with a BA in Physical Education.
He has worked in three different police departments - Peoria, Philadelphia, and Baltimore - staying in each location for an average of two years.
At the end of his stint with Baltimore homicide, he was hired by NCIS (prior to the pilot)
Tony is written as a streetwise, smart-aleck, promiscuous former homicide detective.
He is a flirt who does not respect personal boundaries, going so far as to rifle through his colleagues' possessions, both at work and in their homes, and listen in on private phone calls.
Although Tony is in his late 30s or early 40s, he is typically written as possessing a juvenile sense of humor that manifests itself in many ways - pranks, name-calling, etc.
Tony delights in quoting movies in everyday life.
Although his immature behavior often gets Tony into trouble, he also demonstrates himself to be an insightful agent when the need arises.
Tony's coworkers often display visible frustration with his antics, but just the same, throughout the series Tony has been shown to be very loyal to his coworkers at NCIS, particularly his supervisor, Leroy Jethro Gibbs.
Reeves: Who’s Tony?
Gibbs: An old friend.
Reeves: You’re friends with the bass player from Flock of Seagulls?
Tony: If you think about it, science is amazing. I mean video phone sex. You and Jake ever---
Bishop: Wow. You have no boundaries.
Tony: Come on, I'm messing with you.
Bishop: Did you miss the sexual harassment seminar?
Tony: Every year.