This reminds me of the Mean World Syndrome. From Wikipedia:
Mean world syndrome is a term coined by George Gerbner to describe a phenomenon whereby violence-related content of mass media makes viewers believe that the world is more dangerous than it actually is. Mean world syndrome is one of the main conclusions of cultivation theory. Gerbner, a pioneer researcher on the effects of television on society, argued that people who watch television tended to think of the world as an intimidating and unforgiving place.
Like your experience on local TV, I had a similar thoughts about being on 20/20: