S4·E20 No Exit

When five young people are found dead by the tracks, Goren and Eames initially write them off as a suicide until their investigation reveals that one of the victims, Carmine Ruggiero, had no desire to be part of a suicide pact. Although initially they begin looking into a website that gives instructions on how to committ suicide, their investigation leads them to the unsolved suicide of Edie Elverson, one of Ruggiero's co-workers, whom he had once testifed against in a harrassment suit. Goren soon realises that another of the company's employees, Hubert Skoller, is trying very hard to push them to an answer.