CSI: Crime Scene Investigation

Snuff - S3-E8

Corrected entry: Catherine tells the snuff film producer that they know he was infected with HIV by accidental blood transfer from the actress he killed because they 'tested the DNA of the HIV'. No, they didn't. HIV is a retrovirus - it has no DNA. It has RNA, a far simpler nucleic acid which is completely distinct from DNA. Catherine is a scientist, trained and experienced in genetic 'fingerprinting' - she would never make a mistake like that.

Correction: On the other hand, the producer in question isn't a scientist, trained or otherwise. She has to use terminology that he'll understand, rather than being 100% accurate. It's not the actual truth, but, you know, people do that sort of thing when they need to convince people. Most laypersons know about DNA, but few are familiar with RNA. And police are entirely allowed to lie to you, so that's not an issue either.