For other uses of this name, see Peterson (disambiguation)
Scientist stationed with the Atlantis expedition during their first year in the Pegasus Galaxy. He was unable to hold his cool when it was believed that a contagion had infected the survey team he had joined. What initially was an assessment of water damage to a pier of Atlantis became an outright panic for the civilian, who was determined to escape infection by retreating from the hot zone (despite Elizabeth Weir's order to maintain a lockdown).
Peterson knew almost as much about Ancient technology as Dr. Rodney McKay, and was able to easily bypass the locking mechanisms on the doors inside the city. The infection overriding his ability to think clearly, Peterson was stopped by John Sheppard who eventually intercepted him as he made his way back to the command tower. But John's presence allowed the transport chamber in that sector to become powered. Despite being shot by Sheppard's P-90 the hysterical Peterson entered the chamber and beamed himself into the mess hall, infecting everyone there.
Peterson died shortly afterward, not because of his wounds, but the hallucinatory virus.
Hot Zone - Believing he is not infected (and fervently hoping to remain so) Peterson disobeys the self-regulated lockdown and walks toward the command tower, disabling doors as he goes.