Alasdair R. Schicker (SecNet username: GLancer) was a soldier in the UNSC. He serviced UH-144 Falcons on Reach. Sometime after the Fall of Reach, the Office of Naval Intelligence launched an ‎investigation of a SecNet message exchange between Schicker and Sergeant Poteet to determine whether he had inadvertently leaked classified information, including the location of Reach, to the Covenant. The man receiving the information was dubbed "Yuma."