Shane is portrayed in the television series as a Georgia sheriff's deputy, and is the best friend and partner of Rick Grimes. Shane is wracked with grief when Rick is severely wounded in a firefight with escaped convicts. When the dead began to rise, Shane tries and fails to rescue a comatose Rick at the hospital.[6] He is tormented by having left Rick in the hospital, but also knows that he never would have been able to save Rick's wife and son, Lori and Carl, had he not done so. Shane harbors feelings for Lori, and the two begin a sexual relationship after assuming that Rick is dead. Upon gathering the group of survivors on the outskirts of Atlanta, Shane becomes its de facto leader.[7]

Shane is later shocked when he finds Rick alive and well among a returning scavenger group. Lori, believing Shane manipulated her into having the affair, ends their relationship. At the same time, Shane finds his leadership within the group challenged by Rick. This leads to several instances in which Shane loses both his temper and self-control. In the episode "Wildfire," he is seen contemplating whether or not to shoot Rick in the back.[8] Later, at the CDC's Atlanta compound, Shane gets drunk and nearly rapes Lori, believing she secretly loves him.

In Season 2, Shane reveals to Lori that he plans to leave the group. However, he changes his mind when Carl is accidentally shot by a man named Otis, who leads them to the farm of his employer, veterinarian Hershel Greene.[9] To save Carl's life, Shane goes with Otis to retrieve medical supplies where, in order to escape with the supplies, he shoots Otis and leaves him to the advancing "walkers." Lori is later revealed to be pregnant with what may be Shane's baby. When Shane learns about the pregnancy from Rick, he confronts Lori, who makes it clear that although she is uncertain who the biological father is, she and Rick alone will be raising the baby.

Shane's behavior steadily becomes even more unstable. He becomes focused on turning Lori against Rick, presumably with the hope of reigniting a relationship with her, fathering the child, and resuming leadership of the group. The group resolves to execute Randall, another survivor taken prisoner by the group after he attacked them. However, when Rick refuses to kill an unarmed man, Shane verbally taunts him, boasting that he (Shane) would make a better leader and that Lori loves him instead. Eventually, Shane secretly releases Randall and kills him in the woods, later making it appear that Randall attacked Shane and escaped. Shane then lures Rick into the woods under the pretense of searching for Randall, intending to kill Rick instead. Rick initially refuses to attack his friend and states that he believes Shane will not attack him if he is unarmed. To make this point, Rick begins to hand over his gun to Shane, which ends up being a ruse, as Rick pulls out a knife and stabs Shane. He sobs as he tells Shane that Shane made him do it. Carl, confused about what has taken place, happens upon the scene and shoots Shane through the head when Shane reanimates as a "walker."

In the season finale, it is revealed that Rick - knowing Shane's intentions in bringing him out to the woods - had played along; Rick says he had just wanted it to be over. Shane is mentioned in the first episode of season three by Carol and Daryl, and during episode eight he appears to Rick in the form of a hallucinatory version of a defender of Woodbury, whom Rick shoots dead after initially hesitating to do so.