Riker is a guard at Belle Reve Penitentiary.
Riker guarded the new prisoners Mister Freeze, "Tommy Terror", "Tuppence Terror" and Icicle Jr. to the courtyard, where they were introduced to Amanda Waller.
While Cooper and Hauser led the prisoners to their cells, Riker patrolled the gangways to make sure the prisoners kept quiet.
He was in the mess hall when Mister Freeze staged a coup on Icicle Sr.. After Wilcox activated his collar, Banks and Riker dragged him out of the room.
When Icicle Sr. staged a riot and breakout, Hauser and Riker were still in the main hall. They were easily overpowered and locked away.
Riker participated in a routine check of a truck with medical waste exiting the facility.
The guards at Belle Reve were designed by Jerome Moore, who decided to give all of them a different personality and a nametag.