Forensic Files is an American true crime documentary series that first aired in the 1990s and later found a large audience through cable reruns and streaming, with narrator Peter Thomas guiding viewers through real cases solved by forensic science. Its restrained opening theme became closely tied to the show's methodical, evidence-first style, making it instantly recognisable even without the visuals. As true crime videos, explainers and reaction clips grew online, creators began reusing the intro as shorthand for investigation and deduction, and it remains popular because it sets a serious, credible tone in just a few seconds.