S4, E4: After a young man confesses to murder and could fall victim to the county jail system, Horatio and the team must uncover the truth. Despite Tripp securing a written confession from Tobey Hollins, who admits to committing murder, the evidence tells Horatio that Tobey is innocent. As Horatio races to prove his innocence, Tobey waits for his arraignment in prison and ends up killing another inmate in alleged self-defense. Now, the pressure is on for the CSIs to find out the true culprit in both cases before the system swallows up Tobey for the rest of his life.