Vance Tolsom, a cop that was convicted of murdering his wife, was killed in prison. Investigation into his murder revealed that he was going to receive a new trial based on newly discovered evidence. He had a list of other cops that his wife had had affairs with that had also worked on her murder investigation. Some of the names on the list included Brass, Ecklie, and Detective Vartann.
The CSIs pulled the evidence from the murder of Anne-Marie Tolsom and found that the crime scene had been staged, and matched crime scenes that had been worked by Detective Lucas Martin. Following the lead of Detective Martin's cases the CSI discovered the body of Anne-Marie's sister, Jody, shot to death with Detective Martin's gun. DNA found beneath Jody's fingernails belonged to Anne-Marie.
Detective Martin confessed to helping Anne-Marie fake her murder and frame her husband. A guard from the prison helped her to put the hit on Vance. The prison guard betrayed Anne-Marie and helped the police arrest her.