Michelle McNamara, initially writing a book about the Golden State Killer, became deeply involved in the investigation, experiencing the emotional toll of pursuing a suspect only to have DNA evidence exonerate them. This immersion into the dark world of homicide investigations, coupled with her access to case files, led her to experience vicarious trauma, ultimately contributing to her self-medication and accidental overdose.

Impact: High. This highlights the profound psychological impact of deep-dive investigative work on individuals, even those not in law enforcement. It underscores the dangers of vicarious trauma and the potential for personal tragedy when confronting extreme darkness.

In the source video, this keypoint occurs from 02:59:50 to 03:02:26.

Sources in support: Megyn Kelly (Host), Paul Holes (Former Cold Case Investigator)