Events of L.A. Noire
He is encountered again during the case The Black Caesar, in which he is an officer guarding the crime scene. Upon their arrival, Detectives Cole Phelps and Roy Earle are greeted by Officer Wallis, who then directs them up the stairs towards the crime scene. He stands guard for the remainder of the time. Then when Phelps and Earle catch Fleetwood Morgan, he is the one who takes him into custody.
Officer Wallis made a final appearance in the case Manifest Destiny. He was one of the officers present at the scene of the bus shooting.