Murder Sings The Blues - S3-E7
Factual error: Several police and crime lab personnel are in the train car looking at the dead girl and discussing the possibility that this death could be the result of a bio-hazard or chemical hazard. Later in the episode, ebola and anthrax were discussed. These are level 3/4 hazards which require Hazmat suits and oxygen supplies. At the very least, there should have been very serious access control to the scene. None of them are wearing any type of protective gear except rubber gloves, and there is nothing more than standard crime scene access control. Contrast this with a scene later in the same episode where 2 characters in the lab are wearing respirators when dealing with the dust and other stuff from vacuum cleaning system. If the CSI team or the police really suspected that there was a biohazard or dangerous chemical agent present at the crime scene, then their behaviour was quite cavalier under the circumstances.