Spoiler warning: Plot and/or ending details follow.
Brian Denham was a 23rd century human male and resident of the Federation colony on Tarsus IV.
Originally from the colony on Epsilon Sorona II, Denham and his family were relocated to Tarsus IV after a disaster on Epsilon Sorona made it necessary for Starfleet and the Department of Colony Support to relocate them to Tarsus IV.
Having lost family members to the massacre, Denham volunteered to assist Lieutenant Commander Gabriel Lorca in pursuing former Governor Adrian Kodos and his followers. (DSC novel: Drastic Measures)