One the SWAT officers who is escorting Dulles chief engineer Leslie Barnes to the antenna arrey at the Annex Skywalk was carrying the Ithaca 37 shotgun. Then when they entered the skywalk, O'Reilly shut off the skywalk to provoke the SWAT team. After O'Reilly killed the SWAT commander, the SWAT officer with the Ithaca shotgun fired at the mercenary, but missed O'Reilly when he dived for cover. Then the rest of the mercenaries opened fired at the other SWAT officers. As the Ithaca 37 shotgun carrying SWAT officer fired at Sheldon, who on top of the scaffolding rig, Sheldon kills that office carrying that shotgun with a Heckler & Koch MP5K. The shotgun was last seen near the dead SWAT officer near the skywalk.