When the DA informs Nick that Bart Bowden, a violent man he helped put in jail for the murder of Randy James, is going to have his conviction overturned, the CSI team is tasked with proving the killer guilty once again without using any of the evidence from the original trial. All they have available to them is the forensic evidence from the alley where the victim was murdered, a missing person report, and one eyewitness testimony. To get started, Russell takes Nick to the alley crime scene, hoping to jog his memory, while Morgan and Greg start going through the old forensic evidence piece by piece. Nick remembers a vaguely chemical smell in the alleyway at the original crime scene, and Greg determines that the smell was the result of derma coat, which is used by athletes and tradesmen to quickly seal cuts. Bowden was a mechanic and frequently used derma coat, but this evidence alone isn't enough to retry the case. Bowden has a history of anger issues and More...violent outbursts, so the team decides to look into other murders and assaults that might fit the same MO. They eventually determine that Bowden was in the same area as a near-murderous assault on a woman by the name of Maya Reynolds. As Hodges examines the forensic evidence, derma coat turns up again, but not anywhere near the DNA of the man who was convicted of the crime. The final piece of evidence clicks into place when the woman who found Maya after the attack gives the team a set of keys that her dog swallowed at the crime scene. Nick takes the keys and tests them in Bowden's old car, and the engine roars to life. This, combined with the DNA evidence, is enough to try Bowden again, and the team arrests him just as he is being let out of prison.