This right here is the number one reason why I'd never take a job in the US.
Your fear of coming to the United States, which is second only to France as an international tourist destination, and second to none as a net destination for immigration, is irrational. It is perfectly safe to live in the United States and walk about in public. My children do that all the time. (I say so in a comment in this thread that was posted earlier than your comment.) This news story is news because it is a rare event. But what the news story illustrates is that irrational fear can keep people from doing things that are perfectly safe--like letting their children walk about in public, as I do, or visiting other countries, as I have.