CSI: NY quote, “Sangre por Sangre”

Adam Ross [to Hawkes]: Hey, what do you know about Fishzilla?
Sheldon Hawkes: Sounds like a bad name for a monster movie.
Adam Ross: Close... it's the nickname of that weird little thing I found at the bottom of the mezcal bottle. Yeah, its real name is snakehead fish, all right, and it's illegal in all 50 States.
Sheldon Hawkes: Then it couldn't have been that easy to get. How did it end up at our crime scene?
Adam Ross: Uh, I don't know, maybe it was left as a message. You know, these things are pretty vicious. They eat everything, even their own kind.
Sheldon Hawkes: The message could be in the name. Snakehead... reference to the Mambas?
Adam Ross: I'm trying to track down where you can buy these things and then maybe I can figure out who purchased it.
Sheldon Hawkes: How are you going to track it down if it's illegal and off the books?
Adam Ross: I... I know a guy that knows a guy that... knows a guy that knows another guy.