Brian Timothy Geraghty is an American actor, known for his role in the Academy Award-winning film The Hurt Locker, for his role alongside Denzel Washington in the 2012 film Flight and for his recurring role, as Warren Knox in the acclaimed HBO drama series Boardwalk Empire. He appeared as a regular on NBC's Chicago P.D., as Sean Roman from 2014 to 2016.
Geraghty was born in Toms River, New Jersey, and is of Irish descent. He graduated from Toms River High School East in 1993 and then the Neighborhood Playhouse School of Theatre before beginning his professional career in New York City; he later moved to Los Angeles.
Geraghty was featured in a small role in the crime drama The Sopranos. Feature roles soon followed, in such pictures as Jarhead,Bobby, The Guardian, We Are Marshall, and The Hurt Locker. He also appeared on the January 6, 2010, episode of Law & Order: Special Victims Unit, "Quickie", as a man intentionally infecting women with HIV. In 2013, he portrayed Agent Knox on the HBO crime drama series Boardwalk Empire. In August 2014, Geraghty was cast as a series regular on the second season of the NBC procedural Chicago P.D., playing Sean Roman. 
Notes and Trivia
- Geraghty is 5' 10" (1.78 m).
- He has been in over a dozen national commercials.
- Geraghty is an avid surfer and often participates in charities to raise money.