On Major Crimes Season 3 Episode 18, Philip Stroh is trying to leverage a deal for information on "future murders" and the unit tries to figure out the source of his information in order to stop three murders.
Morales: No matter how many ways you look at it, some things never make sense. All I can tell you is they didn't suffer. Sanchez: How do you know that? Morales: Carbon monoxide poisoning. They were asphyxiated. Probably went to sleep inside a running car, inside a garage.