When off-duty officer Mark Riley is killed during the robbery of a money store, the CSI's puzzle over how suspect Anthony Lombardo sustained a gunshot from the incident but wasn't in the surveillance video or noticed by witnesses. Anthony claims to have been an innocent bystander with no knowledge of the three African American men seen in the surveillance video, but his story is debunked when the CSI's find traces of latex and silicone underneath Riley's fingernails and on the bullet that went through Anthony. The latex and silicone match the mask of an African American man that was punctured by a bullet hole found in Anthony's apartment. Flack brings Anthony in to the other side of the interrogation room to show him that his accomplice Mookie is currently talking to the DA to pin the crime on him. Anthony confesses he was a former employee of the money store and was forced to be the inside man in order to pay back his debts to the third accomplice, Eric. When they track down Eric and put him in the same room as Anthony, Eric angrily explains that Anthony was duped into a confession since Mookie had died in the shooting. We learn that Adam had pretended to be Mookie by dressing in his clothes and used the guise in the editing of footage from a previous time Mookie had spoken to a DA. Eric incriminates himself in the crime in his confrontation with Anthony and the CSI's are able to bring closure to Riley's grieving family.