James Valenti Sr is the former sheriff of Roswell. A witness to the crash of 1947, Valenti Sr became determined to prove the existence of aliens in Roswell, and gave special attention to the death of Atherton and a freak lightning strike that saw the death of an actress during the filming of They are Among Us. His single-mindedness earned him the nickname ‘Sergeant Martian’ among his peers and ultimately alienated him from his unconvinced family. In 1972, assisting Everett Hubble in the pursuit of his wife’s killer, the suspect was shot, and although the sot was fired by Hubble, it cost Valenti his career. Thereafter he begins to slide into dementia until –as when we first meet him –he enters a nursing home. Jim Valenti visits him there but his visits decline in frequency as the series progresses.