Sam was the son of Michael Fuller and followed in his father footsteps by serving as a Starfleet security officer. By 2266, Lieutenant Fuller served as a security section chief aboard the Enterprise. During a workout in the gymnasium in November 2266, Sam was made to disappear by Charles Evans after he laughed at him, but he was later restored by the Thasians. (TOS episode: "Charlie X").
In late 2266 and early 2267, Fuller led his security team on many skirmishes against the Orions and the Klingons, including the engagements in System 1324 and System 7348, and lost many of his men in the line of duty. Fuller himself met his death while defending Starbase 42 from an attack by the IKS D'K'tahg. (TOS novels: The Edge of the Sword, Killing Blow, and River of Blood).