Richard Arnold was a Starfleet officer in the 24th century. He was a captain in 2363.
In 2353, he was listed as a Starfleet Operational Support Services officer on a directory placard in Starbase 32, Maxia sector. His office was located in room #35871. (TNG: "Violations", directory)
In 2368, he was listed as a Warp Technologies Development Group officer on the second version of the dedication plaque of the USS Enterprise-D. (TNG: "Silicon Avatar", dedication plaque)
This character was only mentioned in writing.