Forget what you saw in the movies. Despite the news reports about tourist troubles on Florida highways and the availability of handguns, the United States is a relatively safe place. The typical crime victim in the USA is not a sweet little grandmother or a European tourist.
Most crime victims are single, unemployed, young men.
Members of their own families usually kill murder victims. Our gun crimes scare people. Some people even avoid a trip to the USA for fear of a bullet. Don't worry, you will find little danger. Most Americans have never seen a shooting except in the movies.