D. Knapp was a Human Starfleet officer in the 22nd century.
In 2151, he was named as an Imaging and sensor technologies officer on the dedication plaque of the Enterprise NX-01. (ENT: "Broken Bow", dedication plaque)
In 2154, he was named as a Propulsion Systems officer on the dedication plaque of the Columbia NX-02. (ENT: "Affliction", dedication plaque)
In January of 2155, he was named as a Thermal Operations officer on the directory placards at the Fleet Operations Center, Sol Sector. His office was in room #1323. (ENT: "Demons", directories)
Knapp was named for director of photography Doug Knapp.