It's called "desensitization."
And it's part of the reason viewership of local news continues to head into the abyss.
What does it mean? Well, if your local news leads every day with a murder, then after awhile murders aren't exactly that unusual. And young people watching the news start to think that if murders are basic, everyday occurrences, they can't be all that bad. "Geez dad, murders happen all the time. What's the big deal?"
When young people see this every day, the shock value of a murder begins to fade. They lose their sensitivity to it, and become desensitized. Does this make them more likely to commit murder? To think less of the value of human life? I'm not a psychologist, but I'd guess in some cases the answer is yes.
And it does make parents turn on Raymond instead of your local news.
Remember, we live in a society of obsessive parents. Helicopter parents. Parents who, with enough money, would put their kids in a protective bubble till they're eighteen. If they think something on television is affecting their little darlings, they'll turn on something else.
And if they're not letting their kids watch, they're not watching. Remember, helicopter parents let their kids decide what radio station to listen to and what stations to watch.
While I don't expect stations to stop chasing the scanner (it's too damned easy, right?) I would hope producers keep their more gruesome stories for the late newscast when hopefully the munchkins are tucked in bed.
A while back someone came up with the term "family sensitive news" and the theory was that you kept stuff like grisly crimes off the early newscasts. It was a great idea then, and it still is.
Next time you cover a story about a teenager who has killed someone, think about where he might have gotten the idea that it isn't such a big deal.