Corporal Hornsby is part of the NCR Army contingent deployed to the Mojave Wasteland in compliance with an executive order signed by President Kimball. Serving under Lieutenant Carrie Boyd, Walter is an MP stationed at Camp McCarran. He is monitoring the interrogation of a Legionprisoner of war, found standing guard next to the door to the interrogation room where the officer is being detained.
When walking into the interrogation room containing Lt. Boyd and Silus, he will tell the Courier that Boyd is pissed off.
If the Courier is working with Silus, when Walter walks into the interrogation room with Silus, he will be killed and Silus will take his armor and escape Camp McCarran.
Despite being part of the NCR military police, he wears regular NCR armor.