Randall was a prisoner in Green River County Detention Center.
Randall was a career criminal who spent most of his life in and out of jail including several times in the old cell block of Green River County Detention Center. Randall witnessed the death of serial killer Mark Moody and had to clean up the blood the next day. He also saw Nurse Dolores Glockner once for treatment and heard stories about Glockner being a possible killer of inmates. Randall was eventually released and by the time he returned, Glockner was gone.
When the detention center's old cellblock was reopened, Randall, now 54, was once more a prisoner. Randall noticed the lights flickering and a clock stopping and someone going by his cell. Randall attracted a guard's attention, but the guard refused to listen to Randall and was killed by the ghost of Glockner. Though Randall heard the guard's screams, he didn't see exactly what happened.
Three months later, the warden of the detention center, Deacon, calls in Sam and Dean Winchester to investigate and get rid of the ghost. While mopping the bathroom floor, Sam recognizes Randall as a witness to the guard's death and asks him about it. Randall tells him that people say the stress of the job got to the guard and dodges Sam's question about what he thinks killed the guard. After Randall mentions having been a prisoner in the old cellblock, Sam asks him about the death of Mark Moody, the Winchesters' prime suspect for the ghost haunting the prison. Randall tells Sam how the guards bashed Moody's head in and he kept quiet out of fear of the same fate. Randall also tells Sam how it was impossible to mop up all of the blood.
Later, after discovering that Mark Moody is not their ghost, Sam and Dean approach Randall for information, paying him with cigarettes. Randall identifies the ghost Dean describes as Nurse Glockner but admits to being unaware of what ultimately happened to her. Randall shares the rumors of Glockner being a killer with the Winchesters as well and with the help of Mara Daniels, the Winchesters are able to confirm that Glockner is in fact the ghost they are dealing with.