1998

A friend of Vern Schillinger, Keller became the new cellmate of Tobias Beecher with plans of ruining Beecher. Beecher fell in love with Keller, and Keller broke his heart (and his arms and his legs) under orders from Schillinger.

1999

Keller apologized to Beecher and confessed to prove he was sorry. Then he was stabbed in the back (presumably by Schillinger), but he survived. Beecher ignored Keller, so Keller tried to get Sister Peter-Marie Reimondo to help him, but she realzied what he was doing. Keller helped Beecher in killing Schillinger's son, Andrew, but it wasn't until Beecher fell under the wing of Kareem Said did he forgive Keller. When Keller saved Beecher's life, they started a relationship.

2000

During the Oz shootout, Keller was shot in the shoulder by Guillaume Tarrant. He died, and had an afterlife experience where, he believes, he was sent to hell. He eventually returned to Oz when Beecher's son was killed. Beecher was told that Keller had killed his son, and attacked him with a knife. Keller was transferred to another cell and refused to forgive Beecher. He became jealous when Beecher began to sleep with other men. Keller and Ryan O'Reilly killed Nate Sheman, then Mondo Browne in the hopes of destroying Simon Adebisi's utopia. The murders were blamed on Supreme Allah.

2001

Keller's old friend, Ronnie Barlog, was sent to Em City and became Beecher's cellmate. Beecher had sex with Barlog, so Keller had sex with Barlog too. When the FBI made a deal with Barlog about three murders that Keller had committed, Keller killed Barlog. Supreme Allah returned, and revealed that he knew Keller and O'Reilly had set him up. When Hank Schillinger's body was found (Beecher had had him killed) Keller had a sudden heart and confessed to the murder to protect Beecher and his family. Keller was transferred to Maryland State Pen, and will stay there the rest of his life.

2002

When evidence surfaced that Pancamo had indeed killed Hank, Keller returned to Oz. The day he returned, however, the FBI informed him that there was a witness to one of the three homosexual murders he'd committed. Sister Peter-Marie convinced Beecher's new girlfriend, Catherine McCain (a lawyer) to represent Keller in his trial. Keller also began to sleep with Officer Claire Howell. When McCain learned she was guilty, she refused to represent Keller and broke up with Beecher. Keller turned down sex with Howell, and she beat him senseless. He was sentenced to death and transferred to death row.

2003

His new lawyer was Harrison, Beecher's father. Keller was upset when he learned that his lawyer is dead. His photograph was taken for a fashion magazine's Death Row glamour extravaganza. He was ecstatic when Beecher was finally paroled. Beecher returned to Oz to meet with his "client", Keller. Beecher wanted to prove that the witness who'd seen Keller dump a body was lying. Keller met with Sister Pete and confessed that he knew Beecher was in love. Later, Beecher returned to inform Keller that his verdict had been overturned. Keller was sent to Unit B, where he met with Franklin Winthrop in a utility closet. Keller made out with him, but then snapped Winthrop's neck for having killed Beecher's father. Beecher visited Keller, who was bored in Unit B. He also confessed to having killed Franklin Winthrop for killing Beecher's father. When Keller learned that Beecher has a sexual relationship, he began to act weird. He finally admitted to Beecher that his ex-wife Bonnie has ovarian cancer and needs an illegal medication to relieve her pain. Keller guilted Beecher into agreeing to, despite the fact that it would violate his parole. So while Beecher was getting the illegal drug, Keller called the police and tipped them to it, causing Beecher to get caught and sent back to Oz. Keller approached Beecher in the gym, trying to be friendly. Beecher ignored the man, and Keller lied, claiming that he hadn't meant for Beecher to be caught. Beecher still wanted nothing to do with him, because he knew that (whether or not Keller had done it) he believed that he was capable of it. In Unit B, Schillinger approached Keller and reminisced about when they'd been friends long ago. Schillinger offered that they become friends again. Keller agreed. Beecher ran into Schillinger and Keller in the library and told Schillinger that Keller had killed Winthrop. Schillinger didn't believe him, but later he asked Keller if he did, and Keller admitted to it. Schillinger didn't care. He auditioned for the part of "Macbeth" and got it. Beecher auditioned for MacDuff, and Keller decided to work props. Schillinger decided that Beecher must die, and Keller agreed to do it. Beecher was called to a "special rehearsal", but only Keller was there. Keller tied Beecher up and threatened to kill him with a shank. Then he admitted that he had agreed to kill him in order to save him, because he knew if he'd told Beecher that he wants to save him Beecher wouldn't believe him. Beecher was returned to Emerald City, and Keller went to Schillinger, telling him that the plan is working beautifully. Keller walked by the interrogation room and witnessed Beecher talking to FBI Agent Taylor. Keller approached Schillinger in Unit B and told him that, during his big sword fight with Beecher at the end of "MacBeth", he would give Schillinger a real knife instead of a prop knife. Keller gave Beecher his prop, and Beecher battled Schillinger. Beecher thrust his prop knife into Schillinger, and Schillinger realized that Keller had betrayed him. He dropped dead to the ground, and Beecher looked over at Keller, holding the prop knife. Beecher was in Emerald City when Keller approached him, saying that he was now Beecher's cellmate. Beecher wanted nothing to do with Keller anymore, even though Keller admitted that he'd taken care of the Aryans for Beecher. Keller also admitted that he'd ruined Beecher's parole because he didn't want to live without him. Beecher told Keller that, if he really loved him, he would leave him alone. Keller refused to do that, so Beecher shoved him away. Keller stumbled over the balcony and landed dead on the floor from the fall.