Cameron (Terminator) - Summer Glau

Summer Glau

Four years prior to The Sarah Connor Chronicles, Josh Friedman developed another pilot in which he wanted to cast Summer Glau. However, she was already committed to Serenity, a spin-off film of the television series Firefly, on which Glau was a regular. Despite this, Friedman "always kept her in mind" and, as the pilot for The Sarah Connor Chronicles was being cast, she was called in to audition. Glau did not plan on auditioning, however, because she had a preconceived idea that the producers wanted "statuesque, icy blondes" for the role, and felt that she did not suit such an image. She agreed to audition after being encouraged by her mother to do so and became comfortable with the idea of performing upon the realization that Friedman had a different idea for how Terminators would be portrayed on the show.

Friedman wrote the scene used for the audition; it involved Cameron discussing with John the future in which she meets him, how he saves her life and how she feels about him, even though as a robot she is technically incapable of any feeling at all. The audition continued with Friedman and the other producers watching Glau's fight scenes from her previous work on Firefly and Serenity. Glau was cast in February 2007 with Friedman feeling that "there was really no second choice basically written for her." Lena Headey, who portrays Sarah Connor, revealed Glau's role to the public a month later.

Glau trained with stunt coordinator Joel Cramer to prepare for the physical demands of her role. In learning martial arts for Serenity, Glau used her training in ballet to learn fight scenes by counts, as if they were choreographies. About bringing the practice to Terminator, Glau said, "When you're working with a stunt guy ... and you need to anticipate every swing he's going to take at you ... it's important that you know exactly the timing that it's all going to play out." Training focused heavily on the destruction of breakable set pieces, safety in hand to hand fights and the use of a variety of firearms. Glau was challenged during fight scenes by not being able to move or act humanly by things such as pushing her hair out of her face. Glau modeled Cameron's walk after that of a dressage horse for its precision.