Lieutenant Austin Braddock was a male Starfleet security officer, in the security department aboard the USS Enterprise-E in the 24th century. In the year 2379, he was part of the Piper team under the command of Lieutenant Commander Geordi La Forge, sent to Tezwa's Mount Ranakar to destroy the nadion-pulse cannon firebase located there. Under orders from Security Chief Christine Vale, Lieutenant Braddock had taken basic medical training. Braddock was also trained as a sniper. (TNG novels: A Time to Kill, A Time to Heal)
Braddock continued to serve through 2381, being aboard the Enterprise during the Borg Invasion of 2381. After the Enterprise and the USS Aventine traversed a subspace tunnel from the Azure Nebula ending up near the Carina Arm near the meridian of the Gamma and Delta Quadrants, they were attacked and boarded by a group of Hirogen. Braddock was one of the ten security officers assigned to protect the bridge and Captain Jean-Luc Picard, but the captain refused to leave; second officer Miranda Kadohata ordered Braddock, Cruzen, and Mars to surrender their TR-116 rifles and depart the bridge, an order Braddock only followed hesitantly. (ST - Destiny novel: Mere Mortals)
Spoiler warning: Plot and/or ending details follow.
In 2386, Lieutenant Braddock was part of the away team to the Eizand homeworld, where he was killed in action defending Lieutenants Dina Elfiki and T'Ryssa Chen and Glinn Ravel Dygan. (TNG novel: Hearts and Minds)