Captain Jim Brass: [about Langston] He's a little cranky for an academic, isn't he?
Gil Grissom: Actually, he's an M.D from back east. A colleague at his hospital turned out to be an angel of death, killed 27 patients before he was caught. Langston was the staff's research pathologist, all the morbidity evidence came across his desk, but he was unable to connect the dots. He wrote a book about it.
Captain Jim Brass: Was it any good?
Gil Grissom: I liked it.
Nick Stokes: [In class, Grissom has learned through Langston where to find a DJK victim. Grissom is out with the CSI team in the area where they were told to look] There's ten stab wounds.
Captain Jim Brass: [to Grissom] Guess you won't be leaving just yet.
Gil Grissom: So, let's assume that 'shoe print' was involved in all four murders. It's possible that he knew, Gerald, right? Is it also possible that he was an accomplice of D.J.K.?
Greg Sanders: That would explain the 9 post-mortem stab wounds in Ian Wallace. It's a continuation of the master's work.
Catherine Willows: But if he was D.J.K.'s helper, back in the day, why go quiet for 10 years then suddenly start killing again?
Greg Sanders: Maybe he was doing time?
Catherine Willows: And when he realized that his old partner turned informant, he got scared and killed him.
Gil Grissom: Maybe that's what brought the old thrill back. Once these guys get a taste, it never seems to go away.