The source of American optimism is a faulty view of our past, to which we believe we will someday be able to return.
But once you take a real, honest look at the past, you'll see it was worse than the present. Much worse, in terms of serial killers.
Before, serial killers didn't make the news quite so much because their deeds were hushed up by frightened people, and the extent of their murders were often unknown. A few years back, a South American man turned himself in to the police for the rapes and murders or over 200 boys. The country he was in just didn't have the ability to track missing children, so they had no idea what he had done until he turned himself in. Serial killers have existed since time immemorial.
Where do you think all of the vampire/werewolf/witch legends come from? That is how primiitive people attempted to explain serial killers. This sort of thing has always been with us. There is no reason to believe that this crime is especially bad compared to anything that happened in the past.
Sorry. Plenty of doubts still.
There have been more wicked things than this happening, for the entire 1900+ years that folks like you have been warning us that the Second Coming is just around the corner.
I think that apocalyptic millenialism is a form of narcissism and pridefulness, a belief that these must be the last days because I am here to see them-- and therefore a sin.
No man knows the hour. Certainly not you.
-ccm