In 2003, Gigandet made his acting debut with a guest appearance in the crime television series
CSI: Crime Scene Investigation. In August 2007, Gigandet was cast in the
Summit Entertainment/
Mandalay Pictures action drama film
Never Back Down. He portrayed the role of villainous bad boy and fighting champion Ryan McCarthy, who sets out to take down the film's protagonist. Gigandet and co-star
Sean Faris shared an award for "Best Fight" at the
2008 MTV Movie Awards. In December 2007, Summit Entertainment cast Gigandet in the planned film adaptation of the best-selling
vampire book series
Twilight by
Stephenie Meyer. He signed on to portray the role of the "tracker" vampire
James. Gigandet received his second "Best Fight" award win at the
2009 MTV Movie Awards with
Robert Pattinson. Also in 2009, Gigandet starred as Corporal Gallo in the sci-fi thriller
Pandorum. In 2009, Gigandet was cast alongside
Leighton Meester and
Minka Kelly in the thriller film
The Roommate. That same year, Gigandet starred as the villainous prison guard Chase in the psychological
straight-to-DVD thriller
The Experiment. In 2011, Gigandet portrayed Jonah in the psychological thriller
Trespass and had a supporting role in the vampire thriller
Priest. ==Personal life==