Corporal Grenwick, a Human male, functioned as a Death Star trooper. He was stationed on the first Death Star as both a guard and an interrogator throughout the duration of the Galactic Civil War.
During 0 BBY, Grenwick worked under Sergeant Major Enfield, offering his tactical insight and managing the detention block's operational timetable. As an interrogation specialist, he witnessed Darth Vader's interrogation and torture of Princess Leia Organa from Alderaan within her holding cell.
Shortly thereafter, the Battle of Yavin resulted in the first Death Star's complete annihilation.