Lieutenant General Robert Brewster was a United States Air Force officer and in charge of Cyber Research Systems. He was the father of Katherine Brewster. He was wary of allowing Skynet to take over all defense programs and would rather that a human being was always in control to keep the machines from gaining too much power.
He was originally meant to be a leader of the Resistance in the alternate original timeline, which was created due to the destruction of the Cyberdyne Building. However, General Brewster was killed when Skynet was allowed into all military systems to stop a computer supervirus as T-X activated the prototype Series 1 and HK-Drone kept at the Cyber Research Systems division building, and the machines became self-aware and killed Brewster along with many other Air Force personnel present at the building. In his last moments, Brewster instructed his daughter and John Connor to go to Crystal Peak. Both originally thought it housed the Skynet core and they could destroy it and avoid Judgment Day, but it really was a fallout shelter and he sent them there to guarantee their survival.