A sandtrooper of the Galactic Empire served in a sandtrooper regiment within the Stormtrooper Corps of the Imperial Army with the military rank of captain. During the Rebel Alliance's secret mission to Tatooine, the two rebel droids R2-D2 and C-3PO had the Death Star plans in their possession. Dark Lord of the Sith Darth Vader tasked Commander Praji of the 501st Legion with his elite sandtrooper regiment to search Tatooine for the pair of droids and recover the plans.
After discovering that the droids were in possession of the Lars family at the Lars Homestead, the captain led their troopers to the settlement and had them search the home while the captain questioned Owen Lars and Beru Whitesun Lars. It was then when the captain learned that Owen's nephew, Luke Skywalker, left earlier that morning to lead the droids to their workstations. Suspecting that Skywalker was a rebel sympathizer, the captain sent a detachment to search for the nephew, although he captain suspected his forces would return empty-handed. After obtaining all of the relevant information, the captain and their troops returned to Mos Eisley while the few troopers left behind slaughtered the couple and burned down the homestead.