I think yes, one of its influences is so delicate to notice. And that is that when you so much cruel scenes, you may get really used to it and feel relaxed with it; that is it becomes something normal. So, it spreads.
I also agree with you. For instance, look at all of the school shootings of late. I seriously doubt if so many sick minds just woke up one day and said "I think I will go shoot up a school". I think they were already sick in the head and saw it plagued all over the news, and dwelled on the idea.....eventually taking action. While I agree that we need to be made aware of these heinous crimes, I do think that in several cases, far to much attention is paid to the person doing the crimes. To psycho's they thrive on that attention.